April 27, 2017

REPOST: Confessions Of a Broke Lab Lizard (complete)

This was sent in by an anonymous reader.  Pay attention.

Confessions Of a Broke Lab Lizard
By Anonymous
You don't know me. I'm a politically conservative “small l” libertarian who's not a member of any militia group. Every “militia group” I've come across was full of, and run by, a bunch of whiny assclowns. I own three guns, and neither of them are black or in a military caliber. But I'm not here to talk about guns, militias, or whiny assclowns. I'm here to talk about what I've been doing lately. I like to tinker with electronics. I've started doing it in high school, but have been out of it until very recently. This has been hampered by a lack of hobby cash since the economy around here has gone to shit, but I manage.

It started about a year or so ago when I found this book at a library sale. It only cost me a couple bucks. One of my hobbies is checking out library sales, used bookstores, flea markets, tag sales, pawn shops, and antique stores. Ninety percent of what I by is from these sources. A few weeks later, the local ham club had a swap meet and I found a well-used 1980s vintage copy of the ARRL Handbook for Five Bucks. By checking these places out you can put together a good “poor man's” electronics/science lab. You would be surprised at what you can find! Here are a few things I've found for my lab.

I was at a tag sale one weekend and found this old AM/FM/SW/PB multiband radio (the one on the left) for ten bucks. It works perfectly! The cops around here run a digital radio system, but the local ham repeater, volunteer fire department, and search and rescue team do not. This radio covers their frequencies. That was my first inexpensive radio acquisition. My next radio (the one on the right) cost me the princely sum of $25 from a flea market vendor. It's newer than the Lafayette I first bought, and covers some extra frequencies like aircraft and UHF. I can't hear digital systems on these radios, but I can still pick them up and analyze them somewhat.
A trip to Harbor Freight got me a cheap soldering iron, VOM meter, and some electronic tools I didn't already have (or find cheap elsewhere). The radios I bought are cheap and simple enough that after learning a bit from the ARRL Handbook I was able to modify the radios to do a little extra. I then got lucky at a ham radio swap meet last Fall and found this old Oscilloscope (Heathkit) and Grid-Dip Meter. I like the old Heathkit gear because the manual comes with schematics and you can fix it when it breaks.

I found this old Wavetek Cable TV SAM (signal analysis meter) at a pawn shop. It was used to test Cable TV systems, and became obsolete when TV went digital. It's really a rugged wideband receiver with 4-300 MHz. frequency coverage. It cost a bit ($50), but I can hook up my O'Scope to it and have a spectrum analyzer. That's pretty useful. The only other item that cost me that much money was a brand new copy of the ARRL book Experimental Methods in RF Design. However, I couldn't find one used (I don't have Internet. It's as bad as TV) and it was worth it because I'll save money rolling a lot of my own gear and test equipment now.

My “research library” consists of the following books. Most of them were purchased used at flea markets, hamfests, and used book stores. Only a couple were purchased new. They are:

  • Radio Monitoring, by Skip Aery
  • ARRL Handbook, 1982 edition. Published by ARRL.
  • Radio Science Observing, Volumes 1 &2, by Joseph J. Carr
  • Impoverished Radio Experimenter, Volumes 1-6, published by Your Old Time Bookstore
  • Voice Of the Crystal, by H.P. Fredrichs. http://www.hpfriedrichs.com/index.htm
  • Experimental Methods in RF Design, Published by ARRL.
  • Assorted issues of QST and CQ VHF Magazines, picked up at various hamfests.
  • Various old (1950s and 1960s) radio and electronics books downloaded from the Net and printed out; mostly from www.tubebooks.org.

My local Radio Shack went out of business, but before they did I cleaned out their stock of electronics parts: resistors, capacitors, transistors, ICs, et al, solder, and some small tools at 50-90% off. There don't seem to be very many electronic experimenters around here, so there was a lot of stock there. One the best purchases from Radio Shack was this small red desoldering bulb used to remove components. I look for thrown-out electronics on the curb during trash day, grab them, and remove whatever components I can from them. Old picture tube-type TVs (not flat screen) and “boombox” stereos seem to have the best parts, and are the easiest to scrounge parts from. Old microwave ovens are good for high-voltage stuff. I usually don't waste my time with thrown-out computers because the ones I found were truly junked, but I did find a working 1980s vintage TRS-80 Color Computer once.

So far I think I may have spent maybe $300-$500 on my radio experimenter's lab, most of it bought used from local places. I cleaned up a corner of the attic, got one of those light socket adapters, and ran an extension cord from the attic light bulb to my “bench”. It looks like something from the OSS in World War II. I do a lot of “New World Order”-type radio research up there. All my antennas are homebrewed from wire and coathangers. So far I've found some interesting things on the airwaves, but I'm still doing more research on them. As time and money permits, I'm going to expand the frequency coverage of the lab. I found a couple old radar detectors at a tag sale, and am going to see how useful they may be in experiments. My point to all this is that it doesn't take a lot of money to put together a lab where you can do good research.


Since my last article, I cleaned up an even bigger corner of the attic, and replaced that light socket adapter and extension cord with some Romex going to an outlet at my bench. I do a lot of “New World Order”-type radio research up there. I keep finding interesting things on the airwaves that leave me with a lot of questions to answer. Like that dude from Blade Runner, I've seen and heard things you wouldn't believe.
I went to a tag sale a couple weeks ago, and found a few things for my lab cheap. A “Bearcat 250” police scanner and Heathkit tube tester for five bucks each, and an old Readers Digest Atlas for 25 cents. I found some VHF frequencies using my tunable receivers, and now have something that'll let me listen to more than one at a time. The tube tester I picked up because tube-type radio gear is better protected against stuff like lightning and EMP, and the tester will help me keep any tube radios I get running. The atlas is nice to see just where and how far out I'm listening on the shortwave and lower VHF bands.

All you fellow broke lab lizards should be hitting up your local tag sales, flea markets, auctions, antique stores, and pawn shops. You'll find a lot of good stuff at those places that you can use. At auctions, tag sales and flea markets you should be looking in all the cardboard boxes that have electronics in them. That's where you'll find stuff. Hamfests are also good, but you might not find many that are within reasonable driving distance. You should also go through the science, technical, and DIY sections of your local bookstores, especially the ones that sell used books. I've found some nice titles for less than what you would have paid on Amazon.

Don't worry about what you can't hear. Work on the signals you can pick up with the gear you have on hand. I was corresponding with a friend and fellow broke lab lizard who is finishing up his prison term for something that shouldn't even be a crime in my opinion. All he has access to is this Sony AM/FM Walkman-type radio that he can buy at the commissary. By tweaking the tuning coils this way and that he is able to listen above the AM broadcast band to pick up shortwave communications at night, and listen above the FM broadcast band to pick up VHF aircraft communications. Plans for doing this have been circulating the underground for decades. I have a photocopy that someone gave me from the 1990s that was printed in underground zines like “Full Disclosure” (Issue #30) and “Cybertek” (Issue #9). If some guy locked up in prison can do this, then you should be able to do the same or better. Stuff like this is important because you can pick up old Walkman-type AM/FM radios for a couple Bucks apiece, mod them, and hand them out to people who want to stay informed.

There is this old (1979) book you might be able to find called Communications Monitoring, by Robert B. Grove (ISBN 0-8104-0894-0). He is the dude who founded the old “Monitoring Times” magazine. I got mine at a recent hamfest in a box of old radio books and magazines. It has a lot of good info in it, including directions on how to mod out an AM/FM transistor radio to cover the VHF aircraft band, and how to mod tunable weather-band radios to receive radio signals down in the 150 MHz. range.

While I'm writing this, a line of thunderstorms just passed to the South of my QTH. Some AM band country music station from God knows where is playing Glen Campbell's song “Wichita Lineman,” and I found a few electric company frequencies that are busy with crews cleaning up the mess. Interesting listening. The freq ranges I'm scanning are 37.46-37.86 MHz. & 47.68-48.54 MHz. Give them a listen when the electric companies within a hundred miles of you have a reason to be out working. Sometimes the weather conditions will let you hear signals out even farther than that. The old Bearcat 250 is perfect for this job, and fifty channels is more than enough for now.

I've also been spending a lot of time listening to 25-33 MHz. I'm sure you know that the regular CB band in the US is 26.965-27.405 MHz., and the 10 Meter Ham Band is 28-29.7 MHz., but there are all these radios out there that people can buy that go from 25 to 30 MHz. or higher. Some of the brand names are “Galaxy”, “Magnum”, and “Stryker.” I have also seen old army surplus radios that can tune 20-76 MHz. All this gear with similar frequency ranges means there will be people and small groups simply picking a frequency and using it for a little while before switching to another. The frequency ranges 25-27 & 27.4-28 MHz. (above and below the US CB band) see a lot of use among these hobbyists known as “freebanders,” although I've heard some tactical-type communications that didn't sound like radio hobbyists rag-chewing.

A little birdie told me that I should be paying more attention to 54-88 MHz, especially 54-76 MHz. TV stations originally on channels 2-6 went to higher frequency ranges when they went digital. Now these frequency ranges are not being used. So far I haven't seen any analog pirate TV stations on the lower channels, but there are still all these TV modulator boxes and old VCRs out there that operate on Channels 2 & 3, or 3 & 4. Even Wal-Mart still sells them. Military surplus PRC-25, PRC-77, and RT-524 radios will go up to 76 MHz, and there are plenty of them still around. Some of my cheap multiband portable radios were made to tune in the audio from the old analog TV channels. No good for TV reception anymore, but they'll still pick up audio in those frequency ranges. There are also a lot of small FM audio “Mr. Microphone” type transmitters that work from around 87 MHz. into the low end of the FM broadcast band. All the good FM stations (in my opinion) are below 92 MHz, and the interesting stuff is a bonus.

So as you see, even though you might not running the latest, greatest gear, you can still find cheap stuff that will let you do a lot of “research,” and that's what's important.

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