Richard, thanks for reminding me abiut the attenuator. You sure thats enough? I was figuring 10dB. According to the Resistor tables for a Pi it seems easier. Just my own opinion...

73,
Kelly K5AID

I use an innova 3320 dvm; it showed up in an issue in QST some months back. Its good for what it does.?

73,?
Kelly K5AID?

Hey guys it's Kelly. Took a week off to do some things regarding some python programming, and decided to finally tackle the issue with the receiver not hearing anything. First thing I did was to totally remove the AGC board. I went back and did some digging on ND6T's website. I found some 90 degree header pins and soldered them to the RF path trace that was cut.. I used a flat head screwdriver to GENTLY scrape to the copper traces, this time. Then i placed a (don't laugh) female to female arduino jumper wire on the pins, and powered up the radio. Well, IT WORKS!? Loud and obnoxious as ever...boy i sure have missed my lil ubitx. Oh. My custom field day logbook is ready! (Linux only). Going to enjoy the radio for a spell. See you guys on field day! Look for WA5CC. Cross County ARC.??

73,?

Kelly KD5AJ?
ex K5AID?

Kelly, I would suggest this as a pattern of equipment purchases:

1: a good DVM.? There are good ones which won't break your wallet - and you would want as good as you can find.? I've seen them with all sorts of abilities, such as a (rather low bandwidth) frequency counter, transistor tester, and cap meter.? I've heard some horror stories about Chinese products, but I've used some of their stuff and have had no problems with it.? I use a fancy Radio Shack meter which has been adequate, accurate, and precise enough - and rugged.

(Equally important to a good meter - a good soldering iron.)

2: Look for a used scope, minimum 30mhz bandwidth.? Unless you have a lot of experience with them, stick to a used (but working) analog scope.? I've seen some pretty good deals at hamfests... working condition, for under $100.? The more you know, the more useful it can be!

3: Somewhere near the top, antenna testing gear is a necessity.? If you have soldering experience, I would suggest "rolling your own".? I could point out some inexpensive pieces that can be combined together as a very effective tool.? The Handbook has some good stuff in it, the Experimental Methods in RF design book is much better.? (I combine ideas from that with arduino, and have some really useful circuits, like a wide bandwidth and very sensitive dBm meter that reports signal strength to software or spreadsheet - more than a thousand times a second.)

4: Something that receives across the bands - a general coverage receiver of some sort is (IMO) almost a necessity on a decent bench - something with at least moderate shielding and can receive WWV and so on.? Along these lines, if you work with VHF or UHF, a decent SDR dongle is cheap and can be used for all sorts of things - like checking the deviation (and spurs) on a 2m rig.? I paid less than $30 for mine (NESDR Smart)... and there are some which are better and that can go down well into the HF range (mine stops around 27mhz).?

THEN I would recommend a signal generator.? (It could be combined with #3 to do some impressive work.)? I built my own unit by combining a DDS kit with a good attenuator salvaged from a burned signal generator.? You combine them together in a single case, and shield and ground everything, you can keep leakage to a minimum and have something really useful.? For instance... have a impedance bridge with an unknown ferrite toroid on one leg (with a single loop of wire through it)... drive the thing with the signal generator (programmed, using a computer to step it through a frequency range), and watch the output with the digitizing dBm meter.? Presto - you can with a little reading and math, figure out the characteristics of the toroid!? (Especially if you have a couple of known-value caps you can throw in the circuit...)

With those, you can get really creative.

Bob

N4FBZ

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