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VK3XX > HELP 01.05.08 08:44l 70 Lines 3445 Bytes #999 (0) @ WW
BID : 741604VK3XX
Read: GUEST
Subj: Re: TS830S fault
Path: DB0FHN<DB0RGB<DB0PM<DB0PV<DB0FSG<I4UKI<IR2UBX<IV3SCP<SR1BSZ<ON4HU<
F5GOV<CX2SA<VK4TRS<VK3API
Sent: 080501/0601Z @:VK3API.#MEL.VIC.AUS.OC #:12716 [Lilydale] FBB7.00g
From: VK3XX@VK3API.#MEL.VIC.AUS.OC
To : HELP@WW
Hello to,K0CQ and GM7HUD and other readers,
I have seen postings from you both with the title "Re TS830 fault" which
was a posting of mine to HELP.
I think there is also another posting (G4UEQ?) in reply to this topic
which I havent seen on my BBS. Jerry, you have answered specifically my
posting and I will comment later. Andy, you have apparently seen a messege
talking about a TS870 battery under this topic. Maybe you could tell me if
there was anything in that message which you have seen which gives me any
guidance to my problem as I havent seen it at all here.
Jerry, now to your response. Yes, I can only agree with your comments
about elecrolytic capacitors. I mentioned in my posting that there were 4
off 22mfd caps which I suspected but which I had concluded by a very
basic multimeter check had looked as though they were OK but may not be.
These are associated with the driver and PA supplies and I can believe
that they could give a problem if the leakage builds up after a period of
transmission. They are only accessible after removing the IF board as that
is where I tracked them down to. I set out originally to get some
replacements but local sources with catalogs didnt list more than a few
values of 350+ working voltage.which these need to be. Fortunately I have
sourced some so I will get myself psyched up to get that board out and
replace those to start with. There are also some electros on the rectifier
board for other services which I should also look to changing. That bourd
is also difficult to get out because all connections to it are wire
wrapped!
So we are both thinking along the same track which is where I keep
returning to. Thanks for your comments. The problem I am now convinced is
in the PA box and driver boards and their DC supplies.
Just a further comment from me which you might advise upon. There are lots
of disk ceramic capacitors involved in these circuits eg screen bypasses
on driver and PA which could be breaking down after a period of
transmission. I dont have any experience of those capacitors leaking and
then partially failing due to current flow and restoring after a period of
time again. The screen resistors are nominally 100 ohm really just being a
screen bypass getting their 250 v supply from a separate transformer
winding and rectifier. They check out OK cold but re not difficult to
replace too.
Gerry, you also mentioned rivets in rotary switches. That might be another
possibility as the circuitry for the screen supply goes through the Mode
switch primarily for the Tune process. I used switch cleaner/lubricator
fluid on all the rotary switches last year but I recall having seen
something elsewhere on rivet problems. It looks like you may have seen a
posting which mentioned that in response to mine which hasnt appeared
here.
I know that I am asking a lot trying to get such an old rig working but it
is the challenge as much as the need as I have several other HF rigs
available!
So I sincerely thank you both for your postings and would appreciate
anything else that either of you can contribute. It is great that the
packet system is still good for intelligent replies and contributions.
Andy, you might have some comments to make on ny response to Gerry.
Cheers and
73 - GORDON, VK3XX @ VK3API.#MEL.VIC.AUS.OC
Message timed: 15:41 AEST on 01 May 2008
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