"Al Parker" <[EMAIL PROTECTED]> made an utterance to the drakelist gang
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Hi Jack,
I'd suspect a resistor heating up. Take a look at the one in the
plate line to the driver 12BY7 first. I haven't pulled the skem, but IIRC
it's abt 470 ohm, 1/2 watt, and it gets "stressed", reducing votage to the
driver, and it's output goes down. Also check the cathode & screen
resistors for the finals, abt 18 & 68 ohms respectively IIRC. They also
go high in value, and will affect the balance of teh tubes, and output..
Hope this helps,
73,
Al, W8UT
New Bern, NC
BoatAnchors appreciated here
http://www.thecompendium.net/radio/
http://www.hammarlund.info
----- Original Message -----
From: "Jack Wilson" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, July 24, 2005 3:05 PM
Subject: [drakelist] T4XB
>
> "Jack Wilson" <[EMAIL PROTECTED]> made an utterance to the drakelist
gang
> ----------------------------------------------------------------------
>
> Hi,
>
> I have a T4XB which just developed a problem. All of a sudden, I found
I
> could
> not get it to tune up. After replacing the finals, testing the power
supply
> with another T4XB, and other various operating tests, I found that I
could
> turn the rig on from a cold start with the tune position selected and
the
> current would start to increase on the meter for about 6- 10 seconds
then
> drop
> off to nothing. If I first turned the rig on and let it warm up, then
> switched to
> the tune position, there would be no current indicated on the meter and,
of
> course,
> it would not tune up. I suspect there is a problem with a cap in the
final
> section, but
> this is only a guess on the part of a non techie.
>
> Any suggestions on where to start to find and fix the problem?
>
> Jack
> K1HW
>
> ----------------------------------------------------------------------
> On Behalf of "Jack Wilson" <[EMAIL PROTECTED]>
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On Behalf of "Al Parker" <[EMAIL PROTECTED]>
Submissions: [email protected]
Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body
Hopelessly Lost: [EMAIL PROTECTED] - help in body of message
Zerobeat Web Page: http://www.zerobeat.net
Brought to you courtesy of TLCHost.net http://www.tlchost.net/
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