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Old September 5th 08, 12:34 PM posted to rec.radio.amateur.homebrew
cliff wright cliff wright is offline
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First recorded activity by RadioBanter: Jan 2007
Posts: 58
Default Sending power into rig unused for 30 years : Precautions ?

Andrew VK3BFA wrote:

On Aug 16, 4:03 pm, (Dave Platt) wrote:

Now retired I'm trying to become active again.
My TS-520S has not been on for 30 years.
I don't have a variactor ( variable transformer ).



KISS. Wire a 60w light globe in series, turn it on, let it sit for a
few hours. Filaments OFF for this test.

Havent used a variac for this for years - reason - its the switch on
current surge thats going to kill old electros, and the variac has no
current limiting whereas the light bulb does. You will see a brief
"Flash" as the caps charge up, then maybe a dull glow, eventually, no
light at all.

Given that the caps used were / are modern, and of good quality to
start with, the KISS method works well.

Oh, BTW - when all this is done, apply full mains power, let the tube
filaments soak for a few hours lest they have gone gassy.

Andrew VK3BFA.

Well I still use a kenwood 820s and it goes fine. In fact I'm just
putting the WARC bands into it.
The only parts I would be really concerned about are the 450 vot
electros in series acroos the 800 volt final ht supply. If you were very
careful a good look at the caps smoothing the 300 volt screen and driver
plate supply might also be a good idea. If you do a search on google you
will find all the tech data you might need including circuits and manuals.
It's a pretty good rig except for some poor final tank design on some
bands. a rewind of the Pi network inductor can help a lot and the use of
the proper values for a working Q of 12.
This can give you up to 25 or 30 watts more output on some bands with no
more DC input. It also saves you finals a lot of potential grief. See
the QST 1983 upgrade article for a few ideas.
Cliff Wright ZL1BDA ex G3NIA