My wife has apparently decided to humor me in that she has agreed to permit me to construct a backyard shelter whenever we get around to buying a house -- providing that it also becomes my radio and server room.  This isn't really a problem for me since I had planned on doing this anyway, but it got me thinking: what's the best way to protect my equipment from damage caused by EMP?

I spent some time this afternoon researching this on the Internet, and there really isn't much out there:

 * use equipment as little as necessary,
 * store equipment in a Faraday cage when not in use, and
 * maintain a stock of spare parts

Given the history of amateur radio and emergency communications, one would figure this kind of preparation and information would be a little more complete and easier to find.  Does anyone have any suggestions as to where I can find more information on this topic that is complete, accurate, and useful?

4NEC2 has a *huge* learning curve, for lots of reasons.

The first and biggest one is that the code was written long ago in FORTRAN.  Data files were designed for punch cards (I'm not kidding) with a very unfriendly interface which has zero tolerance for errors.  Data output is... a bunch of numbers.  Great for hardcore engineers, I guess, but it doesn't mean much to me.

http://www.qsl.net/wb6tpu/swindex.html is an excellent archive of NEC-related code.  You should find some GUI frontends that may work for you, and someone's even ported the code to C which makes it easier to build.

Here are the ham-related apps I've got on my palm:

GOLog (http://home.earthlink.net/~golog/) is designed for contest logging.  I used it for the California QSO Party and it worked well.  The Windows sync conduit translates the logs into Cabrillo format suitable for emailing.  I wish there was a Unix conduit.  Ah well.

PocketBeacon (http://www.searat.com/pocketbeacon) displays time in UTC and the NCDXF/IARU beacons.  If you enter your latitude and longitude, it gives the range and bearing from your location to each of the beacons.

PocketSat+ (http://www.bigfattail.com/software/pocketsatplus/) is the best darned satellite program out there.  Really.  It's totally flexible and is fully functional even if you don't pay the reasonable $25 registration fee.

QSO-73 (google for it!) is another logging application I'm looking at.  It includes explanations and examples of standard Q-symbols (QRM, QRN, etc), a Morse code table, and the ability to store a list of frequencies with information about them as well as logging contacts.

Hope this helps!

Well, I corresponded with Clif from Avvid, and it's his opinion based on the information available that repair of this rig will probably not be cost-effective.  Sigh.

Time to go shopping.  I'll be checking for polarity protection as a feature, even though I'll be much much more careful next time.

I have collected results from the AF board.

For obvious reasons, my ohmmeter gave different answers based on which orientation of probes I used.  I tested each combination of orientations and test points.

I zeroed the ohmmeter between each transistor, and I used the X1 setting on the ohmmeter.  It was acting up a little, but these were the best results I could get.

Q3

Red       Black     Ohms
Base      Collector infinity
Base      Emitter   infinity
Collector Base      9
Collector Emitter   infinity
Emitter   Base      10
Emitter   Collector 12

Q4

Red       Black     Ohms
Base      Collector 4.5
Base      Emitter   4.5
Collector Base      infinity
Collector Emitter   infinity
Emitter   Base      infinity
Emitter   Collector 100

The AF board is easily accessible from the bottom of the rig.  I left the ohmmeter on the last time I put it away so I need new batteries.

I did test with the AC power cord, and it immediately blew the 6A fuse.  That points to an internal failure in my books.

I'll get back to you all tomorrow on the AF board tests.

I accidentally put the red power cable on the black terminal and the black power cable on the red terminal.

This blew every fuse in my RigRunner (except the 40A fuse) and it also blew the fuse inside my TNC.  I had two rigs connected at the time -- a TR-7400A which survived unscathed and a TS-520 which didn't.

I have removed the covers from the TS-520, and there are no obviously smoked components.  The only fuse on the TS-520 that I've found is part of the internal AC power supply, which I'm not using.  If I had an AC power cord, I'd try that.  Alternatively, if I could find one of those custom connectors, I'd build one.  Anyway.

When I turn the TS-520 on while it's connected to my power supply, the voltmeter drops to about half a volt and the ammeter raises to about half an amp.  It also causes any other device on the power bus to suffer a low-voltage condition (the TNC resets, for example) until I turn the TS-520 back off.

Suggestions?  I'm totally okay with "send it in to be professionally serviced" if that's the right answer.  I just want to make sure that I've done everything I can before sending it in.

Thanks!

I thought I blew a fuse because I replaced the fuse and powered it on and nothing happened.

Turns out the fuse I had inserted was the same blown one that I had removed.  Duh.

That radio works fine.  Unfortunately, the HF rig didn't survive the zap and doesn't have a nice obvious diode.

I'll post about that in a more relevant area.

Okay.  Troubleshooting would be easier if I had the manual.  If anyone out there has the manual, please let me know.

I believe I have blown the fuse on my Kenwood TR-7400A.

I bought it used and did not receive the manual.  I checked under the top and bottom panels and couldn't find the fuse.

Could someone who has this rig or the manual for it please tell me where the fuse is?

Thanks!

Now that you mention it, I can see that FM signals would need a frequency-domain device, while my oscilloscope is definitely a time-domain device.

I am a little nervous about connecting the output of my rig directly to the oscilloscope.  According to my MFJ, the rig generates 100W.  Shouldn't I have some serious attenuation in place so I don't zorch anything?

I was planning on using a two-tone generator to check for distortion, instead of my voice.  Wouldn't that work?

Does anyone have any pointers on how to use an oscilloscope to check signal quality?  I'd like to ensure that the signals I transmit (CW and SSB on HF, FM (voice and digital) on VHF) are clean and solid.

URLs with documented procedures deeply appreciated, as well as suggested vendors for probes and the like.

Ever since I bought my wife her spinning wheel, I've been wondering how difficult it would be to modify it to generate electricity.

I can get the big wheel going at 90 RPM without getting too tired.  The small pulley wheel on the spindle spins 6.5 times as fast as the big wheel on the slowest setting.  How difficult would it be to build something like an automobile's alternator that would be light enough to fit nicely in the place of the spindle and flyer?

I spent some time on Google looking for prior work in this field, and I'm surprised that I couldn't find anything.  Has anyone tried this?  How was it?

I recently received the December QST which has a very nice article on battery power.  Thanks!

Oooh!  I think I understand what you meant with regard to the diodes.

http://www.ibexmfg.com/appnotes/app07.htm

This page discusses UPS design.  The second diagram looks like it would meet my needs -- keep the battery continuously charged while running the station, with the station using the power supply to run during normal conditions.  The diodes in the diagram are even Schottky rectifiers.  Hmm.

Thanks for your help!