Free E-Book: Software Defined Radio for Engineers

We really like when a vendor finds a great book on a topic — probably one they care about — and makes it available for free. Analog Devices does this regularly and one you should probably have a look at is Software Defined Radio for Engineers. The book goes for $100 or so on Amazon, and while a digital copy has pluses and minuses, it is hard to beat the $0 price.

The book by [Travis F. Collins], [Robin Getz], [Di Pu], and [Alexander M. Wyglinski] covers a range of topics in 11 chapters. There’s also a website with more information including video lectures and projects forthcoming that appear to use the Pluto SDR. We have a Pluto and have been meaning to write more about it including the hack to make it think it has a better RF chip inside. The hack may not result in meeting all the device specs, but it does work to increase the frequency range and bandwidth. However, the book isn’t tied to a specific piece of hardware.

Make no mistake, the book is a college-level textbook for engineers, so it isn’t going to go easy on the math. So if the equation below bugs you, this might not be the book you start with:

[Di Pu] and [Alexander Wyglinksi] have an older similar book, and it looks like the lecture videos are based on that book (see video below). The projects section on the website doesn’t appear to have any actual projects in it yet, although there are a couple of placeholders.

We have enjoyed Analog’s book selections in the past including The Scientist and Engineer’s Guide to Digital Signal Processing which is a classic. If you visit their library you’ll find lots of books along with classes and videos, too.

If you want something a bit less academic, there’s always [Ossmann’s] videos. Or if you’d rather just use an SDR, there are plenty of inexpensive options to choose from.

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What Is Happening with Our Uk Friends?

by Derrick Krane

There are a number of disturbing incidents, events and trends taking place in the UK.

• Muslim refugees who have no concept of western values, or interest in assimilating are invited in to the UK. Some are terrorists posing as refugees. The prior sentence will be labeled as racist and hateful by many. This is a reflexive response heavily laced with self-righteous outrage which has become typical of the left. This reflexive statement is not applicable as Islam is a religious and political system which transcends race, not a race itself, any more than Catholicism, whose proclaimed members include Italians, Irish, Americans, Quebecois, and Iraqis is a race. I do not hate individual Muslims; on the contrary, I feel sorrow for any persons who live under an oppressive system, including Sharia law, or the demoralized and battered people of North Korea. I also have many concerns and reservations about specific tenets of their belief system and their propensity to force it upon others through violence.
• Muslim Grooming Gangs have engaged in mass rape and prostitution of white British girls.
• The population of the UK is disarmed so they cannot defend themselves against terrorism. The police tell people to Run, Hide and Tell if they are involved in a terrorist incident. As observed elsewhere, this sounds like advice given to a middle schooler on how to deal with a bully. This is pathetic and a joke.
• Tommy Robinson, a bold and outspoken man is imprisoned for 13 months for exercising free speech.
• Alfie Evans, a 23 months old toddler, was gravely ill. Doctors want to remove life support. The parents didn’t want life support removed. Italy offered to pay for air fare and all medical expenses in an effort to save the baby. The British government refused, told the parents they are deciding the child’s fate, and posted police officers at the hospital to keep the parents from leaving with their baby. Police also warn people not to comment on this matter on social media or they could face legal penalties.
• The once mighty military of the British has been stripped of funding and weakened

See the video below for more information:

Trends in the US and UK are often reciprocal. Our cultures as so closely intertwined, Social, cultural and political changes which occur in the UK tend to transfer to the US, and vice versa. In the examples I provided above, there is evident suppression of free speech, parental rights, and de facto acceptance of terrorism and violence, a mostly unarmed police force suffering budget cuts and stretched too thin to be effective and misguided law enforcement priorities. Adding to these internal domestic matters is a weakened military. Cultural Marxism, which has spread throughout both the UK and the US plays at least some role in the above problems.

These are disturbing developments. Some may say why should we Americans care what goes on there? We won our independence from them quite some time ago. So how does this affect us? The answer is it affects us greatly, and we should care.

Analysis

These toxins of Political correctness and multiculturalism have infiltrated Western Civilization, weakening and sickening it. The agenda of the left can also be compared to a social form of OCD (Obsessive Compulsive Disorder). OCD is a neurologically based anxiety disorder, which progresses, demanding the sufferer’s attention to more and more irrelevant details, constantly morphing and growing to consume all of one’s time and attention, and dominate one’s life.

It can never be satisfied, no matter what behavioral changes a person makes, OCD will always demand more. Political Correctness is akin to this. There is no definition of a victory or a met goal. It just keep’s taking and consuming more and more, and can never be satisfied. There are no limits as to what it will consume, nor any consideration of the costs. I am genuinely baffled by the agenda of the left.

There are those who believe there is some dark conspiracy to bring about global domination, and a one world government. I would speculate that it is even worse. There are no end goals; rather a relentless and mindless march with no consideration of the consequences, like lemmings off a cliff.

Syria was torn by warfare and ISIS was taking over and occupying land; an unusual if not unheard of action by terrorists. In response there was a flood of refugees. Europe and the UK opened its doors. The left in their unlimited tolerance and compassion for all (expect those on the right) said send us your refugees. There was insufficient consideration of factors such as:

• Will terrorists or ISIS fighters hide among the refugees and enter Europe?
• Will Syrian refugees assimilate to the European cultures and language, and adopt Western values, contributing instead of taking from a society?
• Who will pay for resettling the refugees, and provide them with housing, transportation, food, and medical care? The estimated cost for 20,000 refugees is about two billion pounds (2.7 billion US dollars).
• The result was a de facto invasion, with costly terrorist attacks throughout the UK and Europe.
• Let’s keep going the left says. If you dare express concern or criticism of the Islamic belief system, you are promptly labeled a hate speech spouting Islamophobic bigot. In the US, so far it will “only” cost you your job and reputation. In the UK, it can mean prison time. This is oppression of free speech and the exchange of ideas.
• Feminists are silent about an Iranian woman who publicly removed her hijab, and was incarcerated for two years. Never mind the hijab is a symbol of female repression, in a patriarchal male dominated society, the same type that feminists always seem to be speaking out against. Keep going. The left is not done yet.
• If you are a white, western Christian, and a conservative you are a member of the only group not tolerated by the left. You are basically a piece of excrement strewn with flies on the bottom of a garbage can. You should hate yourself. The agenda of the left is truly unhinged, deranged, and confused.

Yet another concern, which more directly affects the United States, is that a weak UK weakens the US.  While the United States and the British Empire certainly had their differences in the 18^th and 19th centuries, e.g., the Revolutionary war, and the War of 1812, we have since become the best of friends, economic partners, and allies.

The Brits have been at our side through almost every major conflict in the 20^th and 21^st century. We were at their sides in World War I and World War II, and they repaid us without hesitation in Korea, the 1991 Gulf war, Bosnia, Kosovo, the ongoing Iran/Afghanistan conflict, and of late, Syria. But the UK’s Army, Navy, and Air Force have been stripped to the bone through budget cuts. Strong allies add to our strength. Today, the brits are barely capable of defending themselves, let alone expeditionary actions in support of common interests with the US.

Conclusion

The Brits are losing their identity and culture through the insidious, poisonous insatiable greed of multiculturalism, and so are we. British author and psychiatrist Theodore Dalrymple has written extensively about the sad descent into degeneracy that has overtaken the UK, as they have crumbled from a mighty Empire Upon Which the Sun Never Set to a weakened and divided island –nation. We will have to see what changes occur as Brexit unfolds.

For information on Britain’s past military strength, see the videos below:

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Everything You Didn’t Know You Were Missing About Bias Tees

Do you need a bias tee? If you want to put a DC voltage on top of an RF signal, chances are that you do. But what exactly are bias tees, and how do they work?

If that’s your question, [W2AEW] has an answer for you with this informative video on the basics of bias tees. A bias tee allows a DC bias to be laid over an RF signal, and while that sounds like a simple job, theory and practice often deviate in the RF world. The simplest bias tee would have a capacitor in series with the RF input and output to pass AC but block DC from getting out the input, and a DC input with a series inductance to prevent RF from getting into the DC circuit. Practical circuits are slightly more complicated, and [W2AEW] covers all you need to know about how real-world bias tees are engineered. He also gives some use cases for bias tees, from sending DC signals up a feed line to control an antenna tuner or rotator to adding a DC bias to a high-speed serial line.

It’s an interesting circuit, and we learned a lot, which is par for the course with [W2AEW]’s videos. Check out some of his other offerings, like a practical guide to the mysteries of Smith charts, or his visualization of how standing waves work.

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Lucid Dreaming | Falling back asleep for DEILD?

Hey guys, as the title says I've been trying DEILD for about a week or so. I've encountered two main problems associated with it, that stem from the way I sleep.

1) It takes me a long time to fall asleep, maybe an hour is the average time.
2) I've set an alarm to wake me up at 5:30 AM, I typically close my eyes around 11 PM - 12 AM to fall asleep so I SHOULD be asleep by 1 at latest. The alarm only lasts 10 seconds before auto-dismissing but it isn't particularly intrusive.

Thing is, even though I've done everything to make this alarm not intrusive, the second I hear it I'm pretty awake and I find it difficult to fall back asleep to re-enter my dream as DEILD states.

Does anyone have any solutions and/or other lucid dreaming induction techniques they could recommend? Thanks guys!

P.S. My dream recall is passable, occasionally I remember none but most of the time I'll remember at least one. My best is three in one night.

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A Cleverly Concealed Magnetic Loop Antenna

We’re sure all radio amateurs must have encountered the problem faced by [Alexandre Grimberg PY1AHD] frequently enough that they nod their heads sagely. There you are, relaxing in the sun on the lounger next to the crystal-blue pool, and you fancy working a bit of DX. But the sheer horror of it all, a tower, rotator, and HF Yagi would ruin the aesthetic, so what can be done?

[Alexandre]’s solution is simple and elegant: conceal a circular magnetic loop antenna beneath the rim of a circular plastic poolside table. Construction is the usual copper pipe with a co-axial coupling loop and a large air-gapped variable capacitor, and tuning comes via a long plastic rod that emerges as a discreet knob on the opposite side of the table. It has a 10 MHz to 30 MHz bandwidth, and should provide a decent antenna for such a small space. We can’t help some concern about how easy to access that capacitor is, on these antennas there is induced a surprisingly large RF voltage across its vanes, and anyone unwary enough to sit at the table to enjoy a poolside drink might suffer a nasty RF burn to the knee. Perhaps we’d go for a remotely tuned model instead, for this reason.

[Alexandre] has many unusual loop projects under his belt, as well as producing commercial loops. Most interesting to us on his YouTube feed is this one with a capacitor formed from co-axial soft drink cans.

Thanks [Geekabit] for the tip.

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Silenced Firearms for Survival

by Chad

If you are in a situation where the discharge and report of your firearm carries inherent risk owing to disturbance, adding a silencer (AKA suppressor) is the ideal solution to mitigate those risks. Lessening the noise, or report, of a gun is mechanically very simple, and aside from the cost of the “can” itself only requires an obligatory $200 tax stamp and protracted wait time to get BATFE approval.

Nearly anyone in a short or long term survival situation will benefit from having a suppressor on their gun. If you have shied away from procuring silencers due to the perceived difficulty of acquiring the device or make necessary modifications to your host firearm, this article should put those considerations to bed.

We will explore how suppressors work, the basics of acquiring one legally, and examine an overview of some firearms that yield themselves particularly well to being suppressed, and especially for the purposes of a survival situation. Keep your ear-muffs on for now, though, and read on.

A Note on Terminology

Before we delve into the core of our article, I will address the naming convention around suppressors and silencers. The short version is that the two terms are synonymous, but most gun owners and professionals will fall into one camp or the other for use, and mildly berate whoever uses the opposite. In point of fact, Hiram Percy Maxim (son of Hiram Smith Maxim, of Maxim machine gun fame) invented the first firearm silencer, and it was named as such by him. The common use of the word ‘suppressor’ did not surface until sometime after these devices were common.

The federal government also classifies and regulates such devices as “firearm silencers and mufflers,” so there is that to consider. I think it is only right to allow the inventor of something to dictate the name of his invention, but nevertheless, both words are in common usage.

“Firearm muffler” just sounds clumsy. “Can” is slang for a suppressor or silencer. “Suppressor” is technically a more accurate descriptor of such things, considering a silenced gun is far from silent, and is probably why it is so common among firearm nomenclature sticklers.

Bottom Line: “Silencer” and “Suppressor” are both perfectly acceptable terms and anyone who insists you use one or the other knows exactly what you mean and is simply being pretentious, and you should inform them of the fact. I will stick with suppressor for the remainder of the article. Moving on!

 How Do Suppressors Work?

A suppressor reduces the report of a firearm by moderating and reducing one of the chief factors contributing to noise at the muzzle, which is blast; the expelled, hot propellant gasses being emitted from the muzzle behind the bullet. The other chief factor is the supersonic crack of a bullet breaking the sound barrier- more on that in a minute. The aforementioned gasses, when unchecked, erupt from the muzzle of the gun in their characteristic, skull-rattling boom.

By containing these gasses, giving them room to expand, slow and cool somewhat before reaching the atmosphere, the report at the muzzle can be greatly reduced or eliminated, depending on the combination of suppressor, host firearm and cartridge used. This is very similar in operation to the muffler on a car, and interestingly the inventor of the first silencer also designed mufflers  for automobiles (that he also called silencers, ha!).

Suppressors do great at reducing the report of most guns to less than ear-splitting intensity, but the report will still likely be far from the library-whisper “Hollywood” suppressors that make a tinny thwip and nothing else. The “loudness” of this report is measured in the standard unit of decibels, or dB, and suppressor efficiency is rated according to decibel reduction at the muzzle. Note that this value given by any manufacturers is slightly variable depending on the gun and ammo combination and ambient atmospheric conditions.

The other major factor, mentioned earlier, that contributes to the noise of a gunshot is the supersonic signature, or crack, of a high-velocity bullet. This noise is usually less intense than the muzzle blast, but is still very loud, and the farthest thing from quiet. Because it is generated by the bullet itself breaking the sound barrier, the only way to eliminate this factor is to either use slow “subsonic” ammunition, or one of the very few specially suppressed guns designed to actually bleed off the gasses behind the bullet while it is still in the bore, reducing it to a speed slower than sound before it exits the barrel.

Note that many cartridges are so fast supersonic is inherent to the design, and reducing the velocity of the bullet by reducing the powder charge substantially can actually create functionality issues, especially in semi- and full-automatic guns. Other cartridges are slower than sound by nature, and so need not worry about supersonic signature. If one desires a very quiet suppressor and gun combination, one of these slower cartridges may be ideal.  Some cartridges, especially for handguns, can be had in either subsonic or supersonic varieties depending on the weight of the bullet and load.

As far as the design of the suppressor itself, the internal configuration of the chambers and baffles that slow and route the gasses vary depending on the type and manufacturer. This is not entirely important to our discussion here, but suffice to say some work better than others. The attachment method for connecting it to the host firearm also varies, but is typically a thread-on design for pistols and the rare shotgun suppressors, and one of several common “quick-detach,” or QD, methods for rifles, which again vary depending on the manufacturer and muzzle device.

These methods are not universal! You must know exactly how you will mount your suppressor to a host firearm and set it up accordingly. For all the dizzying variation among them, for the novice this boils down to a simple call or chat with a suppressor manufacturer before purchase, and is nothing to obsess over.

Benefits of Suppression

The most obvious benefit of suppressing a firearm is the reduced, sometimes greatly reduced report of the shot. Your neighbors near the range will appreciate it. This might translate into saving your hearing, and that of your family in a self-defense situation. It allows better communication among police when their words are not being drowned out by gunfire. It might mean less spooking of game on hunting land. It may prevent a shooter from being located when firing from a hide, due to less noise and disturbance from blast around the gun.

Do not discount the 2^nd order effects of using all suppressed guns in a team or group setting: a suppressed firearm, even one that is still supersonic, sounds distinctly different from an unsuppressed one. In such a scenario, any unsuppressed gunshot will stick out immensely, i.e. “not one of ours.”

If firing at a distant threat with a suppressed rifle, they may be confused by the seemingly conflicting information reported by their ears; the report, if heard, will sound farther away, and be harder to locate, while the crack left in the wake of the supersonic bullet, if it passes them, will be heard to the side or rear. These two factors are more germane to military or certain law enforcement vocations than the average citizen prepper, but it pays to know the full benefits of a piece of kit should you ever find yourself in extremis.

It is not hard to see how much is gained from adding a suppressor to a firearm. Aside from the cost and acquisition drawbacks mentioned earlier, the only other factor to consider is the increase in overall length and bulk of the host firearm. This may or may not be an issue depending on your application. Carrying a suppressed handgun concealed is no simple trick for most, and a 16” barreled rifle becomes much less handy with another 7-8” added to it. Think carefully about your intended use, and let that guide your choice and modification of the host firearm.

Quick Guide to Hosts: Getting the Least Bang for Your Buck

Suppressors and suppressor theory is a pursuit distinct from guns in itself. I could handily turn this article into a long diatribe on the life, times and future of suppressors and how to wring every last decibel of reduction from one. Instead, I will go over the perks, flaws and suitability of common cartridges, firearm action types and suppressor classes, and the way they interact with each other, which is really where the magic is if you are seeking a very quiet setup. We’ll cover action types first, then cartridges and finally the classes of suppressors.

Keep in mind, reader, that nearly any conceivable combination of action and cartridge can be suppressed, but not all those combinations are effective, or even viable.

Host Action, Handguns

Revolver– Not suitable for suppression owing to the gap between cylinder face and forcing cone (flash gap), lets some propellant escape noisily, ruining any effect of suppressor on muzzle. A tiny number of revolvers suitable for suppression, either by design or modification, do exist. If you know one, say so in the comments. (No cheating with Google!)

Semi-automatic- Suitable for suppression. Typical attachment will be by factory or aftermarket barrel with threaded muzzle, occasionally a QD mount. Typical handgun suppressors, depending on the host design, must make use of a Nielsen Device, or muzzle booster, to offset the weight of the suppressor hanging off the barrel retarding the action. Note that the noise of the gun cycling and ejecting is not insignificant.

Host Action, Rifles

Bolt Action or Single Shot- very suitable for suppression owing to action being well-sealed when in battery and no reciprocating parts or ejecting cases on firing. Typical attachment method today is QD, sometimes thread-on.

Lever Action- suitable for suppression. Can be very quiet if chambered in pistol cartridge or subsonic rifle cartridge. Typical attachment method today is thread-on.

Semi-automatic- suitable for suppression. Reciprocating action and ejection does create noise. May need tuning for reliability depending on host design and suppressor match, may create issues with gas overpressure. Biggest issue is rifle rounds typically supersonic. Typical attachment method today is QD, sometimes thread-on.

Full-automatic- suitable for suppression as above, but suppressor will need to be of higher grade to withstand rigorous firing schedule.

Host Action, Shotguns

Single Shot- suitable for suppression. Surprisingly quiet with right load. Attachment will be via thread-on choke-type mount.

Double-Barrel-  not suitable for suppression. Insufficient space between barrels to mount suppressors.

Pump action- suitable for suppression. Surprisingly quiet with right load. Attachment will be via thread-on choke-type mount.

Semi-automatic- suitable for suppression. May need tuning for reliability depending on host design. Attachment will be via thread-on choke-type mount.

*Note: Shotgun suppressors have only recently become commercially viable, with the flagship design being offered by Silencer Co., the Salvo 12.

Don’t get too wrapped up on trying to figure out if your gun can mount a suppressor. A simple call to any one of the major manufacturers will determine that with certainty, and more importantly, nearly any modern handgun or rifle will with minimal modification.

Cartridge Selection and Consideration

Most any cartridge and gun will benefit from adding a suppressor, but if one desires a truly quiet combination, you can narrow it down to a few choices, noted below. Remember, the supersonic crack of a bullet is the other major factor contributing to noise upon firing, so any gun that utilizes a supersonic cartridge will present that signature on firing.

The rule of thumb for supersonic velocity is approximately 1150 feet per second at sea level. Use that as a coarse guide for determining if a factory load of any cartridge is supersonic. I will cover most common cartridges below.

.22 LR- Supersonic, but easily had in subsonic. With the right suppressor and ammo can get very close to “Hollywood” quiet. Can make superb small game hunting and pest removal solution.

9mm Para.- Most loads are supersonic, but some can be found that are subsonic by design. May require testing and tuning to find consistently reliable subsonic load and suppressor combo. Nearly any modern service handgun can be set up for suppression and more and more factory guns come stock with threaded barrels standard or as an option.

.40 S&W- The .40’s popularity is dwindling, but still a common host. Lighter bullet weights are typically supersonic, 160-165 grain loads vary and nearly all 180 grain loads are subsonic.

.45ACP- A classic choice for quiet types. Most loads inherently subsonic. Makes a great cartridge in handgun, submachine gun or pistol-caliber carbine for very quiet work.

5.56x45mm / 5.45x39mm- Inherently supersonic. Subsonic loads for use in semi-auto rifles present huge functionality hurdles. Suppressor will tame deafening muzzle-blast, but supersonic crack still quite loud.

.300 AAC Blackout, or .300 Blk- Supersonic or subsonic. Niche cartridge, but has some merit as a dedicated subsonic setup. Mentioned here as one of its primary design objectives was to offer reliable .30 caliber suppressed performance in M4 carbine family of weapons.

.308 Win. / 7.62x51mm- Inherently supersonic. Same principle as 5.56mm applies here.

12 Ga.- Varies by shot/projectile type and load, typically supersonic.

As for the variety of other rifle and handgun cartridges, rest assured that there is in all likelihood a suppressor for it out there. Whether or not your given host is suitable for it is another story; generally speaking, the more popular the host gun, or widely adopted it is, will mean it is more likely to have an off the shelf solution available.

Suppressor Design and Compatibility

Suppressors are designed to function on a pistol, a rifle or a shotgun. Some suppressors are designed to function on a rifle or a pistol, sometimes called multi-use suppressors. Typically, a suppressor will function with the cartridge it was designed for, and smaller (but not always!) with a small loss of efficiency.

Depending on the make and model, it could be made to disassemble, allowing the user to service and maintain it, or not, being serviceable primarily only at the factory. You will see info on compatibility listed plainly with most suppressor product info.

Obtaining a Suppressor

Suppressor ownership is fairly straightforward, and available to citizens in most states. As of the date of this article, nearly every state in the U.S. allows suppressor ownership and their use in hunting. Assuming you live in one of those permissive states, the following criteria apply for purchase:

• Must be a U.S. resident.
• Must be legally able to purchase and own firearm.
• Purchaser must be 21 years old.
• Purchaser must pay $200 transfer tax per suppressor to the BATFE.

There are a few more hoops to jump through, like notifying the chief law enforcement officer in your jurisdiction about taking possession of the item. That sounds bad, but before 2016 you either had to get permission from that law enforcement officer to take possession (resulting in de facto bans in some areas when permission was never granted) or take possession in either a trust or corporation, which is still an option and may be best depending on how you want to protect your asset. You will of course have to submit paperwork, photographs and fingerprints. Expect a wait time of months to a year before you can take possession of your new suppressor.

If all this talk of bureaucracy is making you sweat, don’t fear: many suppressor dealers and manufacturers have extensive experience with getting new owners up to par painlessly. Once you have made the decision to purchase a given model, give them a call and let them get you going down the path to ownership with a minimum of stress.

Conclusion

While tedious and expensive to acquire, the practical and tactical benefits of a suppressor make the process worthwhile. Suppressors increase safety, efficiency and reduce hazards when engaged in nearly any type of shooting. Make the commitment to obtain one if the benefit to your objective is worth the financial and time investment.

Additional Resources

Some considerations in this article were simplified for brevity and ease of reading. Below you will find several links to manufacturers and organizations that can explain use, ownership and legal considerations in greater detail. I suggest you look at them.

American Suppressor Association- Focus on state and federal level lobbying, and public education. Great resources on their site. https://americansuppressorassociation.com/

Dead Air Armament- Makers of high-quality, innovative suppressors. http://deadairsilencers.com

Gemtech- One of the older and most prolific suppressor manufacturers. http://gem-tech.com

SilencerCo.- Another big name in suppressors. http://silencerco.com

Surefire- Known for flashlights, but they also make super heavy-duty cans. www.surefire.com

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Portable Ham Radio Design Fosters Experiments

[Charlie Morris] has been busy building a portable ham radio rig and documenting his progress in a series of videos. You can see the first one below. There’s four parts (more if you count things like part 4 and part 4a as two parts) so far and it is always interesting to see inside a build like this, where the choices and tradeoffs are explained.

The first part covers the Si5351 VFO and the associated display. There’s very little to the VFO other than off-the-shelf modules including an Arduino. You can also see the portable Morse code key which is actually a micro switch. The second part experiments with audio amplifiers. [Charlie] looked at the NE5534 vs discrete amplifiers. He was shooting for lowest current draw that was usable. Other parts discuss the RF amplifier and the receiver. Despite the VFO, there is quite a bit of non-module parts by the time things start shaping up.

There’s a lot of good information about why he selected particular devices and component values. There’s doubtless more videos to come, but there’s enough there now to get started. You can not only pick up some design ideas, but looking at the neat prototype construction can give you some thoughts too.

We aren’t sure what the final project will look like, but we are sure it will be interesting to follow along. [Charlie] has done other homebrew radio design videos and they are always educational.

If you want to look more into the audio amplifier part, you might enjoy our take on the common emitter amplifier. If you want some more to watch about RF design, we like [Michael Ossmann’s] workshop.

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Silicon Bugs In The FTDI FT232R, And A Tidy RF VCO Project

The AK Family of Rifles: A Primer

by Chad

In the U.S., the AK family of rifles has enjoyed considerable, if controversial, popularity among civilians and American enthusiasm for it is today higher than ever. The AK-47 and its variants are the iconic rifle of the Russian Federation, the former U.S.S.R. and a host of former Communist Bloc states. It is found in the hands of fighters and farmers in nearly every corner of the developed and undeveloped world.

The Kalashnikov family of rifles is renowned for ruggedness, simplicity and punch. It has been produced both by official and unauthorized manufacture across the globe in such vast numbers that today its numbers are literally countless. Whether or not you are considering an AK variant for your own purposes or dismissing it as the firearm of our enemies, it is in your best interest to learn the ins and outs of the globe’s most plentiful assault rifle, including its semi-automatic commercial cousins.

In this article we’ll examine the AK family in basic detail, covering the design history in brief, and major variants with their cartridges, operation and considerations for use and equipage. We’ll bust a few myths, and hopefully leave you with a better understanding of this most ubiquitous of rifles.

The AK-47: Design History and Evolution

The AK family of rifles was first properly conceived in 1947, by Mikhail Kalashnikov, one of the 20^th century’s most prolific and respected small arm designers. In his youth, Kalashnikov was attracted to all kinds of machinery, and worked as a mechanic. During World War II, after conscription into the Red Army in 1938, Kalashnikov was made a tank mechanic owing to his engineering skills and small stature.

Later he was promoted to tank commander, and after being wounded in the Battle of Bryansk was recuperating in a hospital in 1942 when he overheard fellow soldiers lament the shortcomings of the Red Army’s issued rifles. Dismayed at their opinion of their weapons, Kalashnikov then had the idea to design a new one, one that would eliminate these shortcomings to give his fellow soldiers an effective battlefield weapon to compete with other nations. This idea would evolve into the basis of the AK-47.

The Soviet leadership during World War II was greatly impressed by the German progenitor of assault rifles, the Sturmgewehr 44. Chambered for an intermediate cartridge, this new weapon combined the accuracy and range of a rifle, with the maneuverability and firepower of a submachine gun.

The Soviets wanted something comparable, and badly, and so in 1944 devised an intermediate cartridge of their own, the 7.62x39mm. Kalashnikov, after much design and refinement, and several rounds of competition and trials against more experienced designers of small arms finalized his rifle design, chambering the new Soviet cartridge in the year of 1947, and calling it the Avtomat Kalashnikova, literally Kalashnikov’s Automatic Rifle, model of 1947.

The AK-47 later entered army trials in 1948, but was not formally adopted until 1949. Initial production was hampered by some difficulties and design revisions: the very first AK-47’s, the Type 1’s, were made of stamped steel receivers, but challenges with welding and alignment during manufacture led to the adoption of a second type, with a milled steel receiver. It was much heavier, but lent itself better to immediate production owing to the existence of the needed milling machinery and tooling. Thanks to these changes and other snags, the rifle did not see widespread distribution to the army until around 1956.

It is here that we encounter our first major variation of the AK family; the heavy, milled steel receivers are the archetypal AK-47, specifically the Types 2 and 3. They are easily identified by appearance, their lack of rivets on the receiver, heft and a distinctive milled rectangular lightening cut on both sides of the receiver over the magazine well.

The AK-47 was upgraded in the year of 1959, going back to a stamped sheet steel receiver, a slanted brake on the muzzle, internal changes to prevent the rifle from firing when the bolt was out of battery. This revision, the Type 4, is better known as the Avtomat Kalashnikova Modernizirovanniy, or AKM, the “M” meaning modernized.

The AKM and its variants are far and away the most plentiful and widespread, being the most commonly encountered today whether or not of licensed production. The AKM is easily identified by its light, riveted and stamped receiver, which also has a small pill-shaped detent just above the magazine well.

The AKM served as the basis of the AK-74, developed in the early 1970’s by Kalashnikov, and is identical in operation and function to the AKM, and differs predominately in its new chambering: the 5.45x39mm, designed to compete with the then new American M16 and its light, fast 5.56 x 45mm cartridge.

The AK-74 and its derivatives are today the main infantry assault rifle of most former U.S.S.R. countries.

A Note on Verbiage

Speaking strictly for American users, most will use “AK-47” or “47” as shorthand for any AK variant chambered in the original 7.62mm cartridge. Most will likewise use “AK-74” or “74” as shorthand for referencing a gun chambered in 5.45mm. “AK” or “Kalashnikov” is used broadly to refer to any rifle in the AK family, or a specific rifle. Individual countries or companies model names will usually be entirely different.

The total number of models, variants and country-specific permutations of the AK family of rifles is nothing short of mind-boggling, and beyond the scope of this article. Instead of making this a historical or reference work, I’ll instead paint with a broader brush and cover things pertaining to the AK-47/AKM and AK-74 designs at large.

The topics we cover will be applicable to the families of rifles as a whole, and will help you make informed decisions about selection and employment, if applicable.

Design Elements and Controls

The AK action is typified by a handful of hallmarks: great reliability and ruggedness in all conditions, a long-stroke gas pistol system, a distinctively slanted or vertical gas block, generous tolerances between moving parts, a large curved magazine and a large, somewhat unwieldy safety and selector lever on the right side of the receiver.

The entirety of the AK design is designed to enable cheap and quick production, and greatly simplified training in its manual of arms. Furniture can be made of any combination of wood, plastic, or metal, in a wide array of colors or finishes.

AK sights are a simple rear notch and hooded front post. The rear notch is usually graduated to allow adjustment for target distance without tools. Windage and elevation adjustment for zeroing is achieved with the front sight, being threaded for elevation and on a driftable base to allow for windage adjustment. This will typically require a tool for the purpose.

The AK, while renowned for its simple design and ease of manufacture also varies wildly in quality from country to country, or manufacturer to manufacturer. One of the most pervasive myths about the AK is that it simply will not break or malfunction as long as it is an AK, and that one hammered together by untrained laborers in a nameless town with no electricity will shoot and shoot and shoot until the end of time.

Like anything else, especially with guns, you get what you pay for, and an AK variant from a maker that is known for fine quality materials and fitment will be a far better and more reliable rifle than one dredged as parts from some undeveloped country and assembled by minimum wage workers. Do not believe the idea that you can pay $350 or $400 for a commercial AK in the U.S. and come away with a quality gun by virtue of it being an AK.

AK magazines are either made of metal or plastics, and vary greatly in their quality and reliability depending on pattern and country of origin. Due to the sheer number of variation between both guns and magazines, you will run into more occurrences of fitting and functionality problems here than, say, with an AR or G3 rifle.

Identification of AK magazines is another sub-article in itself, but let it be said you should give the same care and consideration to selecting your magazines as you do your rifle. 7.62x39mm magazines are easily ID’d against their similar 5.45mm cousins due to their more pronounced curvature.

Insertion of the AK magazine is accomplished by hooking the front tab of the magazine into a lug at the front of the magazine well and then rocking it reward until it engages the magazine release with a pronounced click. This operation will be very fiddly for those used to straight-insertion designs until practiced.

The magazine release is a lever directly behind the magazine well on the underside of the receiver. To remove the magazine, the thumb presses this lever toward the muzzle as the magazine is rocked forward out of the magazine well.

The selector lever of the AK is 3 position: Fully up is Safe, the middle position is Automatic, and fully down is Single, or Semi-Automatic. The design ideology was that a user under serious stress will swipe the selector from safe all the way down to single, and placing the gun on automatic requires a deliberate action.

The selector functions as a dust cover, sealing the receiver when on safe and preventing the bolt from cycling reward enough to strip and chamber a cartridge. Operation of the selector is challenging for right handed shooters, and typically mandates breaking of the firing grip entirely if not using an aftermarket selector lever.

A few countries versions have a modified selector lever that is also engaged by the shooting hand thumb, and consists of a lever on the left side of the receiver just above the pistol grip. This lever is typically forward for Safe, and Rear for Single, with the middle position being Automatic. Operation of this lever is slaved to the main selector lever on the right side of the receiver.

The charging handle protrudes directly from the bolt on the right side of the action, reciprocates with the bolt upon firing and can be grasped with either hand for cycling depending on the technique used.

The AK trigger is unremarkable, save for its typically middling pull. Some variations of the AK are known for a phenomenon known as “trigger slap,” where the trigger is somewhat violently reset by the reciprocating action, and causing discomfort or even pain to the shooter’s trigger finger.

The AK typically does not have a bolt lock, and the bolt not lock open after the last round is fired, and relies either on a notch in the selector lever for achieving this manually or a certain type of magazine equipped with a follower that will restrain the bolt in its reward position after the last round is fired. Using such a device, the bolt will close if the magazine is removed.

Loading and Unloading

To load any AK, follow the steps below. The following assumes you are starting with no magazine in the gun, and the selector off safe.

1. Insert a loaded magazine at proper angle, rocking from front to rear until it engages.
2. Grasping the charging handle with either hand, pull the bolt all the way to the rear, then release, letting it go home under full spring power.
3. Rifle is now loaded and ready to fire. Engage safety if not firing immediately.

The unloading procedure is the reverse. Extra care must be taken during unloading of an AK compared as you must disengage the safety to retract the bolt enough to eject any cartridge in the chamber.

1. Remove magazine by grasping magazine and pressing magazine release forward with thumb. Magazine is rocked from back to front out of magazine well.
2. Move selector off of Safe position.
3. Grasping the charging handle with either hand, pull the bolt all the way to the rear, observe for ejection of chambered cartridge.
4. Release bolt, or engage bolt hold-open if featured.
5. Rifle is now unloaded.

Cartridge Performance: Which Should You Choose?

The 7.62x39mm and 5.45x39mm are completely different cartridges. The venerable 7.62mm, with a projectile weight of 120gr. – 155gr. And muzzle velocity of 2,100fps- 2,430fps falls somewhere between the U.S.’s domestic .300 Blackout and .30-30 Winchester in performance. The .300 Blackout has a slightly better ballistic coefficient but is typically slower with a similar weight of bullet, while the .30-30 Win. can push heavier projectiles faster than the 7.62mm across all loads.

The 5.45x39mm’s closest domestic analogue is the 5.56x45mm, having been designed by Russia to compete with the 5.56mm after they took a good, long look at U.S. employment of that cartridge in Vietnam. The 5.45x39mm uses bullets weighing anywhere from 52gr. to 64gr., with muzzle velocities between 2,800fps and 3,200fps. The inspiration for this cartridge is obvious when ballistic data is compared to the 5.56x45mm.

The 7.62mm, while punchy with good penetration and performance against intermediate barriers, has a ballistic shortcoming in its significant drop at even close-mid range. The average 123gr. Bullet fired by an AK with a muzzle velocity of around 2400 feet per second will drop approximately 42 inches at 350 yards, and will have shed around 1000fps if velocity. That is almost 4 feet!

In comparison, the 5.45mm 7N6 standard load, firing a 53gr. bullet will only drop 28inches at the same distance. The 5.45mm thanks to its superior velocity and ballistic coefficient is much “flatter” shooting at typical engagement distances. Either will serve well for an anti-personnel rifle, but the 5.45mm has far less recoil than the 7.62mm, is significantly lighter, and has better effectiveness with most loads against a human target than the 7.62. Modern armies and agencies have moved away from .30 caliber rifles in the intervening decades for a reason!

Neither7.62 or 5.45 is known for accuracy, but this is mostly due to the majority of AK’s not being particularly accurate rifles, not because the cartridges are inherently inaccurate. Modern commercial ammo fired from another rifle, or even a high-end commercial AK variant can produce excellent groups all the way out to 300 yards and beyond, with many commercial loads being capable of producing around a 1 ½  MOA group at 100 yards.

Your biggest advantage selecting the 7.62mm in the US is going to be cheap and plentiful ammunition. If you do not mind the added weight and recoil, the 7.62 still serves well even today, and modern, high-performance bullets make it significantly more effective than with legacy loads.

5.45mm ammo is not nearly as easy to procure, especially since the ATF banned importation of common surplus military loads from Europe and Asia, but is available and affordable if one is willing to order quantity online. The lighter recoil, and flatter trajectory make the AK-74 a joy to use, and if optimized for accuracy, a real competitor against nearly any Western rifle.

Optimization

A plethora of domestic and foreign aftermarket performance parts and modifications exist for the AK family of rifles, from tuned triggers to stocks, grips and extended handguards. Muzzle devices and extended controls are common, as are optic mounts. You will find modern AK’s equipped with everything one would expect to see on a fighting rifle: lights, lasers, foregrips, IR illuminators and more.

The issue with this newfound modularity is that of weight. Russians historically place weight-savings very low on their priority list when designing small arms and the AK is no different. An AK is a fairly heavy gun when loaded. It is even heavier when saddled with modern accoutrement, and a 7.62 gun can easily tip the scales at 10lbs plus.

The issue of optics mounting is more a problem of expectation than execution. Americans are used to simply mounting an optic to the top of the receiver of most guns, and expecting that rigid receiver to hold zero. Considering the AK’s entire receiver top cover is removable for disassembly and is far from an optically consistent fit, you have a couple of choices:

1.) Install an optics rail in a more rigid location, typically in front of the trunnion over the gas tube. This omits the use of most magnified optics.
2.) Utilize an AK specific side-rail mounted optics base. Contrary to popular opinion, a quality mount on an in-spec rail is very rugged, and not likely to lose zero, but it will necessitate either a cheek riser or more of a “chin-weld” on the stock to see through the optic.
3.) Gamble on some abominable Gun-Show Special replacement top-cover with a rail welded on and set screws to increase rigidity. Pray it works, then curse when it inevitably fails.

#3 is always poor decision unless the solution is from a high-end, AK-centric manufacturer. Numbers 1 and 2 are both acceptable depending on what optic is desired.

When preparing to purchase and install mods and accessories for an AK, you must keep in mind that the sheer number of variations means some parts are designed only for country or regional specific variants. Other parts which should be “bolt-on” will still require a degree of hand fitting to install. Things like trigger and hammer installation are just not as simple or as fool-proof as the installation on an AR. They are typically achievable for the average user, but may require a different approach or tools than normal. When in doubt, consult the manufacturer of either component or rifle.

Considerations for Domestic Use

If you buy a quality rifle and decent ammunition, you should expect a very high degree of reliability out of your AK, certainly comparable to most Western standbys. Do not expect to buy a dirt cheap $300 import parts-kit gun and get a 25,000 service life out of it; people that try to convince you otherwise citing that they “never had a problem” with their “flawless” cheapy have not even put 500 rounds through theirs. As I mentioned above, an AK is not invincible or trouble-free just by virtue of being an AK. Quality speaks. Seek it.

The AK is noticeably less ergonomic than the AR-15 family of rifles, specifically the safety, very short fixed or folding stock that lacks adjustable length of pull, and cramped stock handguards. Manipulations like reloads and taking the rifle off safe will be slower and more prone to error compared to an AR without practice. This is not to say that you cannot obtain a high degree of speed with an AK. You certainly can, but the AR and other western designs simply make some actions easier to accomplish.

A sort of elephant in the room may be the AK’s status as the “Bad Guys’ Gun.” This is probably too much to unpack in this article, but I will give you my thoughts and opinions on the matter and let you make your own decision. First, the AK is also the “Good Guys’ Gun” and serves in one guise or another as the primary infantry rifle of several allied or friendly nations, or as the basis of their domestic variant. I believe technology is agnostic in this regard, and the AK has only the cultural value we assign to it.

Second, the gun culture in the U.S. reflects, well, the rest of our culture: most Americans value merit over nationality, and we happily assimilate foreign people and products that offer benefits or improve our lives. A huge swath of U.S. manufacturers, gunsmith, customizers and gun owners have seen fit to enshrine the AK here and make it a part of our landscape.

The AK’s popularity is booming, and the commercial sector is responding in kind, thanks to a grassroots effort by enthusiasts. More quality domestic AK’s are available now than ever, along with a host of high-performance upgrades. A well-tuned AK is as much a hot-rod as any high-end AR.

All that being said, one must still stop to consider a more subtle issue. This is a rifle that has been depicted on targets, in movies and other media, constantly, and I do mean constantly as being the weapon of bad guys. I mentioned it above, but how would this possibly affect someone’s perception of the person who wields it?

I do not mean to insinuate that, for instance, using an AK in an otherwise righteous home-defense shooting would create any undue legal trouble if the rifle was legal, but I do worry about a case of mistaken identity if a cop or someone else happens upon me in some unknown situation, wielding the distinctive silhouette of an AK, one that he has no doubt engaged many, many times on the target range in practice of just such an occasion. This is admittedly probably only a plausible issue in times of serious societal unrest or worse.

I could be way, way out of my lane with that line of reasoning, and it will take a much smarter person than me to sift that for truthfulness, but there it is.

Bottom Line: If you like or prefer an AK for whatever reason, and spend the money and time to both invest in a good one and train with it like you mean it, it will serve you well, and is able to accomplish well most things you could ask of any general purpose intermediate caliber rifle.

Conclusion

The AK family of rifles is the world’s most ubiquitous and plentiful rifle, bar none. From the mind of a wounded tanker, the AK-47 spawned innumerable variations in the aftermath of World War II, and has been present in nearly every major conflict of the 20^th and 21^st centuries. If you love the AK loathe it, you’d be best served to know how to make the world’s most popular rifle work for you.

What’s your opinion of the AK? Do you prefer yours in 5.45mm or 7.62? Let us know down in the comments section!

via Modern Survival Online https://ift.tt/2MlcuQa

VCF East: SDR on the Altair 8800

You’d be forgiven if you thought software defined radio (SDR) was a relatively recent discovery. After all, few outside of the hardcore amateur radio circles were even familiar with the concept until it was discovered that cheap USB TV tuners could be used as fairly decent receivers from a few hundred MHz all the way up into the GHz range. The advent of the RTL-SDR project in 2012 brought the cost of entry level SDR hardware from hundreds of dollars to tens of dollars effectively overnight. Today there’s more hackers cruising the airwaves via software trickery than there’s ever been before.

But as it turns out, the RTL-SDR project wasn’t the first time software and hardware serendipitously combined to allow hackers to pull back the curtain on the world of radio. All the way back in 1975, an article written by Steve Dompier was published in the People’s Computer Company Newsletter and republished in Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia in 1976 that described a very curious discovery. Nearly a decade before a team at Raytheon would coin the term “software radio”, the article showed that with just a few lines of code one could generate AM radio transmissions from their MITS Altair 8800.

At the time, this was a huge deal. Some even argue that it made an AM radio one of the first I/O devices for use with the Altair 8800. At demonstration of the code at a meeting of the Homebrew Computer Club reportedly ended in a round of wild applause, and Bill Gates would later describe it as one of “The best demo programs I’ve seen for the Altair.” A particularly strong endorsement, considering at this point Gates would have been pushing Microsoft’s BASIC language for the Altair, which this technique didn’t use.

At the recent Vintage Computer Festival East, Bill Degnan showed off an evolved version of Dompier’s original concept that he calls “Altair Jukebox” (on this page you can also find a PDF version of Steve Dompier’s 1975 article). Even 43 years after the discovery that the Altair could perform such a feat, it delighted everyone who stopped by the table. With the LEDs flickering away as the songs came strong and clear through the nearby vintage AM radio, the whole thing seemed almost magical. It’s no wonder Bill Gates was impressed.

How Does it Work?

Naturally, more than a few people wanted to know exactly how the music was being generated. For awhile Bill even had the top off of the Altair so you could see inside; akin to the magician pulling up his sleeves so you can see he wasn’t hiding anything. No, there was no little AM radio transmitter hidden inside the Altair, the effect is simply the product of carefully generated electromagnetic interference (EMI). In truth, it’s due more to a design flaw in the Altair than anything else.

Inadequate EMI shielding in the computer allows a nearby radio to pickup the switching noise of the electronics, causing considerable interference in the low AM frequencies when it’s in operation. Similar effects have been observed with other computers of the era, such as the PDP-8. You can pickup the interference regardless of what program is running on the Altair, it’s just that most programs will generate unstructured noise. But with skillful manipulation of this effect, it’s possible to create something that’s actually quite pleasant sounding.

As it so happens, this is almost precisely the mechanism which has recently allowed the use of cheap USB VGA adapters as software defined transmitters. The interference generated by the device, normally nothing more than an annoyance, is expertly honed to become a useful transmission. Seems like the best tricks never get old.

Taking Requests

Bill took the original research published in Dr. Dobb’s and created a much more polished experience. Rather than having to toggle in data for each song you want to hear on the front panel, the user now has access to a menu which allows them to select from pre-defined pieces stored in the program. The upshot of all this is that anyone could sit down at the table and call up a song without any knowledge of the software or even the Altair itself necessarily.

As an added bonus, Bill had set up an absolutely mint TRS-80 Model 102 as the terminal for the day’s demonstration. Which served as both an excellent example of the incredible battery life the Model 100/102 could achieve with nothing but AA batteries, and a chance for attendees to get hands on time with something different in a sea of green and orange CRT terminals.

The dichotomy between the Altair with its brazen LEDs flickering away madly and the overtly 1980’s Model 102 definitely stood out on the show floor, and it seemed the chair in front of the Tandy was rarely empty. Based solely on the number of times one could hear it launch into the Star Wars theme during the course of the show, it’s safe to say this demonstration was a huge hit today. Just as it was all those years ago at the Homebrew Computer Club.

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Lucid Dreaming | My way of becoming lucid (coffee, exercise, reversed WBTB)

Hey everyone! Nice forum!

Okay this is my own way that I had most success with. It's a combination of exercise, coffee and a variation of WBTB. Please tell me what you think and if you have any tips how to refine it. I don't know it this actually fits more into techniques. I wonder alot about this, or if it's even concidered a technique.

This is how i do it:

First, during the day, I make sure I get a little exercise. It doesn't have to be intense or drastic. Just to get a little sweaty and enough get into a relaxed state. Biking or a speed walk for 20-30 minutes seems to be just fine.
During the evening I don't drink any caffeine! For those nights I have used decaffeinated coffee, but that me because I really love coffee.

When I get naturally tired at night I go to sleep but for max one hour. Then I get up, and stay up for about 3-5 hours, I think somewhere after 4 is optimun. This part could be a little hard, since I have exercised during the day and don't have any caffeine in my system, so I could probably wake up from deep sleep and I have to fight the temptation to fall back to sleep. I have a sophisticated alarm which I can't turn off easily and that helps alot.

Next I make a little coffee, and just a little. I have used about one teaspoon of instant coffee and that works fine for me. It might be good to wait an hour after wakening before drinking it, so my body doesn't have too much time to metabiloze it during the hours im gonna be awake.

Rest of the time, before going back to sleep again I kinda do what I want, nothing too intense or I might have trouble falling back to sleep again. I don't really think or read about lucid dreaming during that time, although it'll probably help too, but I do keep lucid dreaming in mind. Then I just go to sleep, and have a simple intent of being lucid.

Let's get on to the lucid quality. It's not bad at all but I don't get to a crisp, clear LD right away. What seems to happen at the begining of my dream is that I don't reailze fully that im dreaming, but it doesn't take long until I get fully aware, usually not by any RC, just automaticly. I feel concious when I look around and it feels real. Im aware that im asleep and can wake up and can carry out my will. I don't come to think of all my ideas of stuff I want to try in LDs, right away. But I think it's most due to that I get a little overwhelmed by being lucid, the scenery and all the possibilities. If i don't have a strong intent of what I want to do before hand, then I mostly end upp "fooling around" like exploring, flying, having sex or whatever spontaneous ideas I get at the time. So if it's it someting specific I want to try it's a good idea to have the intent before getting to sleep. What seem to happen sometimes is false awakeings, but I can't recall if or when I have ever lost lucidity to that, so it doesn't bother me much. I just wake and get lucid right away when I have done this.

I feel like the most crucial to this is relaxation (trust me, exercise it helps alot), caffeine, timing and mindset (interest, always have LD in mind troughout the day). I think dream recall matters too, and I do keep a dream journal, but I don't write every single day and most of the time I don't write much, just a few sentences, so I try to write at least something.

One feeling I get is that it's more successful the longer I stay up before gong back to sleep again, but if I stay upp for too long i might not be able to fall back asleep. What I want is to get that cozy, sometimes kinda "dreamy" feeling when I get to sleep again. Like im pretty awake but relaxed enough to be able to fall asleep. It's just like i have to get the right balance. Sure, I usually take vitamin B complex and turmeric when I try this, sometimes SJW or rhodiola, but I don't think those are too important. But the caffeine really feels like a key ingredient, keeps the mind awake and maybe some REM-rebound going on? Oh! Forgot to mention that i use tobacco, and that affects dreams alot and it's stronger than cigarettes (like chewing tobacco, you'd probably heard of "snus" in sweden) and sometimes i accidently fall alseep with it. I don't know if it have anything to do with it but sometimes i went back to bed just when the sun is about to rise.

It is very similar to WBTB but the difference is it's like in reverse. Instead of sleeping for 4-6 hours, you sleep for 1 hour. And instead of staying up 45min-1h, you stay up 3-5 hours, sometimes even more. I haven't had much success with normal WBTBs. This made me have LDs two day's in a row and other times not may days apart, but those times i didn't get LDs I didn't do everything right either, so it does require some effort and free time.

I just feel that i have finally found my golden cow on how to get lucid, and have confidence that I will succeed, if I do it right.

Im gonna call it something, mostly for puns: :laughtillhurts:
(EC)RWBTB - (Exercise Caffeine) Revesed Wake Back To Bed

I would be really glad if this "technique" could be refined somehow or that you could pin point what factors that matters alot and/or what else I could try? By the way I don't really want to get into any strong supplements like Huperzine or Galantamine, maybe i'll try sometime, who knows.


Thanks in advance!

via Lucid Dreaming - Dream Views - Attaining Lucidity https://ift.tt/2szJJ9k

Safe and Secure Apartment Living

by Derrick Krane

Burglary is the intrusion into an unoccupied or believed to be unoccupied commercial or residential property with intent to steal items within.  Home invasion is the intrusion into an occupied or believed to be occupied residential property with the intent to steal items within, and/or assault, murder, rape, kidnap or hold hostage the residents.

Both can occur during ordinary days and nights in an urban area with police several minutes away with a 911 call, in a rural area with unreliable phone service and police 30 minutes away, or during periods of civil unrest or a natural disaster with no 911 service and police otherwise occupied.

Your home is supposed to be a place where you feel secure; where you can relax and let your guard down.  In order to feel this way, you need to have a home that has redundant security measures in place.  If you live in an apartment, you will have fewer options than if you own a house for making your living space secure. You can still greatly improve your home security by taking some appropriate measures that will not involve radically altering the property.

Before you move in…

• How is the crime rate in the area? Look at the crime statistics not just in the city, but the area of the city you are locating to. Crime stats show the overall crime in a city, but crime tends to concentrate in specific urban areas, in what is called crime distribution.
• How well has the property been maintained? How much care has the landlord put into the apartment? If the property has been neglected, door frames may be rotted, which will make the best locks and solid doors of limited value.
• Are you moving in with someone? If so, are you in a healthy relationship? If there has been abuse or domestic violence while dating, it is doubtful it will get better if you move in together. If you are moving in with a roommate, how well do you know them? Are they into anything they shouldn’t be, such as selling drugs? Personal safety and security starts with who you invite into your life.

Once you have selected your place…

…do a security survey of your apartment. How would you get in if you were a burglar? Some details to consider:

• Are all of the doors illuminated at night, or would you be able to break in through a dark back or side door?
• Are the doors made of a solid hardwood, or are they hollow, or pine? If the door is solid, is there a peephole? How close are the deadbolts in a door to a window in the door? Could someone elbow out a window and reach in and turn the deadbolt? Is there even a deadbolt, or only an in-knob lock?
• Select an apartment on the ground floor, close to an exit. This will make it easier if you have to GTFO.
• How close are the neighbors? What kind of neighbors are they? The type who would call the police if they saw someone breaking in, or would the neighbors be the ones breaking in?

11 Steps to a More Secure Apartment

1. Securing doors

A solid door, in a sturdy frame, secured with a deadbolt is the best option. Have the landlord change the locks when you move in. With the landlord’s permission, a barrel-bolt lock can also be installed on the door. This will give you a little more security when you are home, and there will be no need for another key for you or the landlord. Use the longest screw possible, not the short little ones included with the lock. The strike plate should also be secured with the longest screws possible.

A noisemaker on the door is another layer of security. Attach bells to your doorknob so any movement of the door will make a jingle.

2. Securing windows

Start by keeping the shades pulled down at night. Don’t let the bad guys see you or what you have.

If the windows have sash locks on them, always keep the windows locked when you are not at home. Ask the landlord if you can install a second sash lock.

Place items on the upper and lower window sills of the first floor that will make a lot of noise if they fall as someone tries to get in. Decorative glass bottles, or jars filled with rocks or shells are an option. Not all burglars are concerned with noise discipline, but those that are can be deterred in this way. It will be very difficult to enter through a window without making noise.

Plant blackberry bushes outside your window, and put a table of cacti inside. Make it unpleasant as possible for a burglar.

3. Cameras

Game trail cameras are used by hunters to determine the amount of wildlife traffic in the area they intend to hunt. They are motion activated to take still images or video. They are inexpensive, water resistant, rugged, easy to setup, and many models have night vision. They are a cost effective surveillance system.

There are no wires or wireless to set up. All you have to do take them out of the package insert the SD card and batteries, and they are ready to go. The cameras can be set up to cover the inside or exterior of your place. To stay on the right side of the law, check local ordinances regarding video surveillance, as well as with your landlord if you are going to place cameras outside.

4. Lighting

Burglars want to work in the dark, so deprive them of this option by illuminating your doors at night. LED bulbs are bright, and low cost to purchase and operate.

5. Get to know the Neighbors

Introduce yourself to your neighbors, learn their names, make some small talk, and see what kind of people you have living the same building as you. Work to get along with your neighbors and avoid any drama. See if people have a sense of community; if they look out for each other, and if they are alert to strangers loitering or observing the building.  See if there are suspicious individuals living in your building or frequently visiting. (More about spotting predators in another article).

6. Mail pick-up

Have a trusted neighbor or friend pick up your mail, or have it stopped at the post office while you are away. A pile of mail is a sign to burglars that says come here and break in.

7. Keep your valuables and schedule off of social media

This is the modern version of letting your mail pile up. Don’t go on social media and show off your new jewelry or high-end electronics, followed by posting when you will be at work or how long you will be out of town. Anybody can be watching.

8. Get training and stay sober, fit, and alert

Don’t be the helpless victim of a home invasion. Get training so you know what you are doing, and know the self-defense and use of force laws in your jurisdiction. Part of being a good neighbor is avoiding over-penetration of adjoining walls. You will need to learn the advantages and limitations of various options for home defense.

If you should have to use a firearm to defend yourself, choose a gun and ammo which will likely incapacitate an intruder, but not likely punch through to your neighbor’s apartment.  Hosing down an intruder with pepper spray is another option, but pepper spray in an enclosed area will result in contamination of your apartment, and it will probably waft through the entire building.

What good are skills and knowledge if you are too drunk or high to use them? Avoid heavy use of alcohol or any illegal drugs, or misuse of prescription drugs, as this will weaken you and make you a target as your life becomes unmanageable.  Many burglars target people buying or selling drugs. If you are involved in the drug trade in any capacity, it is inevitable that your life will be touched by theft or violence.

The same goes for sitting and eating and letting yourself go. Develop and maintain a high level of fitness. You will be a less attractive target.

Develop the proper mindset. Be alert, aware of your neighbors and what is going on in your community, but not paranoid.

9. Protecting and Hiding valuables

Get a safe for emergency cash or precious metals.

Get renters insurance. You can add on items such as electronics, cameras, guns, or jewelry against theft or damage, even when these items are removed from you property.

Off-premise redundancy will provide further insurance against total losses if all the above fails and you are burglarized. Redundant thumb drives or external hard drives, hard copies of critical documents and records, and some emergency cash should be stored off site in a safety deposit box, your car, a locked office cabinet drawer, or gym locker.

Find discreet hiding places in your apartment for valuables, or bury a watertight container off premises, and/or on premises if you have a backyard.

10. Make a safe room

In the event of a home invasion, a safe room is a secure room within your secure apartment where you can retreat to and hold out until help arrives. Ideally, the walls should be thick and made of concrete and the door should be the sturdiest in the house, set into a solid frame, with a deadbolt. A phone and firearm secured in a gun safe are also components of the safe room. This may not be possible in an apartment setting, so you will have to get creative and improvise.  Does your apartment building have a laundry room or cellar?  This may have to do if you can get out of your apartment, but not the building.

11. Be ready to GTFO if the situation calls for it

In addition to or in lieu of a safe room, be prepared to evacuate, or Get The Family Out. (I am providing the more polite version of this acronym here). Note all of the exits, and make certain they are clear of obstructions. If you couldn’t score a first floor apartment, are their fire escapes? Or will you need an emergency ladder to egress?

Conclusion

Assess your situation objectively, keep perspective, and don’t get paranoid about home security. The purpose of securing your home should be to reduce anxiety, not increase it. If things are that bad, it’s time to move and/or consider some serious lifestyle changes. .

via Modern Survival Online https://ift.tt/2sCXvrB

Tracking CubeSats for $25

CubeSats are tiny satellites which tag along as secondary payloads during launches. They have to weigh in at under 1.33 kg, and are often built at low cost. There’s even open source designs for these little spacecrafts. Over 800 CubeSats have been launched over the last few years, with many more launches scheduled in the near future.

[Thomas Cholakov] coupled a homemade cloverleaf antenna to a software-defined radio to track some of these satellites. The antenna is built out of copper-clad wire cut to the correct length to receive 437 MHz signals. Four loops are connected together and terminated to an RF connector.

This homebrew antenna is connected into a RTL-SDR dongle. The dongle picks up the beacon signals sent by the satellites and provides the data to a PC. Due to the motion of the satellites, their beacons can be easily identified by the Doppler shift of the frequency.

[Thomas] uses SDR Console to receive data from the satellites. While the demo only shows basic receiving, much more information on decoding these satellites can be found on the SDR Satellites website.

This looks like a fun weekend project, and probably the cheapest aerospace related project possible. After the break, watch the full video explaining how to build and set up the antenna and dongle.

via Radio Hacks – Hackaday https://ift.tt/2sy79fn