Another consideration: current FCC rules require harmonics to be at least 43dB below the fundamental, the article says the filter shown is good for only 34dB. When you design your board, consider adding a five or seven stage output filter, then you should be OK with the law.

Looks like an interesting transmitter. I'll keep the schematic handy in case I decide to build one myself. GL on your build.

I like K1WJ's answer--they're no longer required, but they're nice to have and look through from time to time. Many years ago I operated air mobile, but I left that job and began a new career in a different town. One day, thumbing through an old log, I saw that one of my AM contacts was with a lady ham in a neighboring town. I found out that she had become an SK, and that her son was keeping up the family hobby. We became good friends.

I also keep copies of my license grants in the log, as well as a copy of the mandatory RF exposure survey, and any other pertinent station data. For example, when I installed my last two antennas, I recorded the Rr, Z and SWR of each, and the tuner settings that produced best matching, so that if anything goes wrong in the future I can refer back to my installation notes. I've also got the serial numbers of all my equipment in there as well.

I may be wrong, but I think you still need to keep records of any third-party traffic. Current FCC rules are available online, and I'll have to check to be sure, but I do it anyway.

My initial thoughts are that the coax is OK, and that the 10 and 15-meter traps are OK, too. So I might check the 20-meter trap and 40-meter add-on. Here's why; I've seen a lot of baby spiders get into tight places and grow into grown-up spiders, weaving webs that can get water soaked from condensation and rain, and sometimes even plugging drain holes. My first inclination is to check the 20-meter trap.

What I think may have happened is that the end cap failed and allowed water into the antenna. You said the rain was heavy at times, and end caps do go bad with lots of UV from the sun and from any hail that you may have had over the past several years. It may look fine from the ground, but it could have holes or cracks in it that you can't see.

Another possibility is that corrosion has slowly set in somewhere around the 20-meter trap. The resulting aluminum oxide crud has effectively removed the trap and/or top element from electrical continuity with the rest of the antenna. I'd check that, too.

You'll probably have to take the antenna down and dismantle it. If you can, pop the end caps off the traps and check that everything is alright inside--chances are you'll have to clean and seal each one. Check the caps as well--they could be cracked and/or about to disintegrate. You can order replacements from the manufacturer, which I would probably do anyway. If you do have to disassemble the antenna, clearly mark which element is which, and which end is toward the fed end (or outer end), so when you put it back together you get it right.

You will probably need to check for oxidation corrosion at each joint as well, and might have to scrape each down to base metal again. If that's the case, use a ScotchBrite pad or something like it, and something like NoAlOx compound at each joint when you reassemble the antenna.

It's doubtful that you will need to replace the coax, but it wouldn't hurt to do it anyway. I would check it with a 50Ω dummy load at the antenna end to insure that the SWR is close to 1:1. If it is, the coax is still good,  but if you're going to make the antenna work as if it were a new antenna, then you might as well make the coax new as well.

Good luck troubleshooting it. Let us know what you find--your feedback will help others in a similar situation. GL

My first rig was a Yaesu FT101E that I bought second-hand for $600 at a ham radio store more than 30 years ago. That was a lot of money then--probably still is, especially for used equipment. Today that radio can be had for around $100, and it still covers most of the ham HF spectrum.

Then I went to the Dayton Hamvention, attended a seminar hosted by Bob Heil, K9EID, and saw how easy it was to convert a CB radio to 10m FM. When I got home, I found a modifiable CB at a thrift mart for $2 and bought about $15 worth of parts to do the mod. I had a blast with the converted rig--working stations from Seattle, Wash. to Miami, Fla. while driving around in Oklahoma City. It was a lot of fun, for less than 20 bucks.

There are still some bargain rigs out there, especially if you consider some of the kit radios. Take a look at the Vectronics kits, the kits offered by NorCalQRP.com; those at www.qrpkits.com; those offered by Dave Benson, K1SWL; and the popular Steve Weber, KD1JV, kits. You pay extra because you have to buy a soldering iron and solder, but prices are within reason, and half the fun is in building it on your own.

Consider this--golfing is a pastime that will initially set you back hundreds of bucks for the clubs, bag, and balls. Then it costs extra every time you play--in greens fees, lost balls, lost bets, and beer afterwards. A ham station is pretty much a one-time expense; thereafter it costs only 10¢, probably much less, for every hour you use it. That's a lot cheaper than golfing, boating, shooting, and a host of other hobbies.

Congratulations of the license. You'll soon find that ours can be an inexpensive hobby after all. GL es 73.

Citizens Band, anyone?

And you don't necessarily need much power on UHF when your communication range is generally limited to line-of-sight.

It could be a cold solder joint. I've seen it in a lot of homebrew projects--the solder job looks good, but dirt, grease, insulation, etc. sometimes prevent good connections. It's probably in the vicinity of where you put your finger when you do get signals. GL

Perhaps you've seen the expression, "QRP is when you care enough to send the very least!"

I like it.

I hope that means 10⁶Ω to 10⁸Ω (10MΩ to 1,000MΩ), otherwise don't apply power to the circuit--the mat will become a very hot dummy load almost instantly!

I have a 5-foot wide ESD mat at work, but in a pinch I have used empty ESD bags as improvised mats. They may not be as good, nor as fancy as the real thing, but seem to get the job done nonetheless. GL with your setup, and thanks for the info.

I've been happy with this one: http://www.autekresearch.com/va1.htm.  The links on the web site tell more.  I like it because it is shirt-pocket sized, operates from a single 9V battery, and has an auto-off feature. GL

I'd rather have the miniscule insertion loss and be able to instantly see SWR anomalies than to not have it in line and miss a potentially costly problem. That's my 2¢ worth.

"I don't know if this original stuff contains any PCB's or not."

It's probably best to replace the oil with something you know is safe. Your local electric utility probably has barrels of PBC-free transformer oil and might let you have a gallon for free, or at little cost. Another substitute is mineral oil, which you can buy by the gallon at a tack shop, farm supply store, or from a veterinarian.

Here's the deal; if you have an antenna that exhibits a perfect match (ie. 50Ω ±oj) to the feedline and transmitter, practically all of the power generated by the transmitter will be radiated.  For a less-than-ideal antenna, less than ideal power will be radiated.

Antenna tuners will help minimize losses in the transmission line, and will deliver more power to the antenna, but cannot turn a bad antenna into a good one.

In your case, I'd set the antenna where it has the most wire in the radiating element, then tune the tuner to lowest feedline losses. A bad antenna will never be as good as an efficient one, but bad antennas can be made to work where better antennas are impossible.

GL.

I would not waste the effort of putting the knife switch at the antenna side of the transmission line--I can't see that it will do much good there.  What I would do is connect the ladder line to the antenna (good planning to use the pulley). On the shack side of the transmission line I would have the spark-gap connected to ground rod, as you plan, and would run the line through a metal bulkhead that is also connected to the ground rod.  I would then mount the knife switch on the inside of the metal bulkhead, within easy reach for disconnection when you are not using your radios. The switch's bottom terminals can go to your radio or tuner, the top terminals to the bulkhead (or, for fun, to a neon bulb, so you can watch the flashes of static charges).  The knife switch location inside the shack will be a lot more convenient, and the metal bulkhead will do much to keep direct lightning strikes outside the house.

There were plans for building a spark plug spark gap in older ARRL handbooks and antenna books. Depending on the distance between electrodes, the gap would be safe for powers exceeding a kilowatt. Polyphaser or Alpha-Delta lightning arrestors in the coax between the tuner and rig, properly grounded to the entry bulkhead, will further protect your radio. GL

Depends somewhat on the device, but it's easy enough to step down the voltage to a safe level. Voltage regulators, such as a 7808, will take 12V at the input and deliver 8V at the output. Circuits should be online and in the ARRL Handbook. Another approach is to use a string of diodes to lower the voltage. Each silicon diode in the series will drop .6V, so a string of six will drop 3.6V, enough to lower 12V to 8.4. Use something like 1N4001s or so, with a current rating high enough to handle your "device" current. A third approach is to use a voltage divider or potentiometer, but don't forget to figure in your device's resistance and current requirements when calculating resistor values. GL