Sunday, May 22, 2011

Field Day's Coming Up....

Just talked to my son, who'll be taking Friday morning off to help set up, and all day Saturday off to play radio with me again this year. It's kind of a father-and-son tradition, and it's a lot of fun for us both.
Friday night we had the annual "White Elephant" sale where people bring in stuff they no longer want/need, and yours truly does the "auctioneering".
We only raised about $550 this year, a far cry from some of the years where we raised almost $2000. In a way it's good, though, as in the big money years we had a lot of donations from Silent Key estates, so less equipment coming in as donations mean fewer people passed away.
I was too busy this weekend to start checking out my gear, but I'll get started on that next weekend. I did manage to (finally!) get the lights wired up and tested on my little tower trailer, so the next milestone for that will be the DMV inspection and registration so I can hang a license plate on it and be 'legit'. With signs all over the roads out here in Kaliforniastan about traffic fines now being $1,000 ( ? ! ? ) in "construction zones", I'd hate to even think about what they'd clobber you with for a non-registered, non-licensed vehicle.
And now that I've got my Heathkit SB-310 running so well, I started in on my Heathkit "Mohican" GC-1A receiver. As usual, all the controls and switches will need cleaning, and I'm sure I'll have to do an alignment on it. I tried powering it up today for the first time, and nothing....nada.....zip....completely dead. I started checking the battery pack (it takes EIGHT "C" cells), and found the negative lead of the pack was broken loose from the lug on the connector it goes to. Replaced the 40+ year old wire with a new piece, plugged the pack back in, and it started to work. When I shut it down, I pulled the battery pack to disconnect it, and I noticed the batteries were HOT. Uh-oh....never a good sign! Looking at the schematic I saw that there were several electrolytic capacitors directly on the 12 Volt line, so I pulled the chassis out of the case, and one of them (in the audio section) had failed, and the end plug was pushed out of the can about 1/8". I was planning on replacing all of the electrolytics and any other tubular caps in there, and this just confirmed what I've known for years, that you really have to replace these things when they're this old. If the radio had been in use, the electrolytic capacitors probably would have stayed "formed", but these old design types aren't sealed very well, and once they dry out they become more resistor than capacitor.
Don't have any of that value in easy reach, so I'll stop tomorrow on the way home from work and grab a bunch.
Oh, and the dial cord for the bandspread dial has slipped off the drum, and the drum on the main tuning capacitor needs to have the hub soldered on. Somebody tried using some epoxy to "fix" it, but since it's a brass hub on a tin-plated steel drum, soldering it is really the way to go. Since I have to take the whole front panel apart to re-string the dials, I'll solder *both* drums to their hibs, and be done with it.
Have a good week, everybody!

2 comments:

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  2. Seeing as how it's already mid June and I just now read this page, I wanted to mention that when you solder that dial cord drum onto the Mohicans hub be sure to use "Tix" solder, NOT electronics solder. The reason is that the Tix solder is much, much harder and therefore stronger, it's worth the effort to buy some from the MicroMark catalog. Hope this helps out. BTW I love my Mohican despite its flaws. 73 Michael KD5FPO@juno.com

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