SB-104A 10 Meter Problem

[Multi-Volti Devices]

That's why I called it SOB-104A...

10 m is where is is prone to oscillation. Power out 110W but no signal in
receiver means the signal is probably on another frequency other than where
it should be...my guess somewhere between 30 and 40 MHz. Ask Ron/RTO what to
do (rtoxl at andrews.edu). My memory is really rusty, but I think you need to
align the 10 m slugs with the board in the chassi, not on extender board. I
don't remember much else. Might be a mod to address that, but it's the
reason I was always afraid to work on an SOB-104 without a spectrum
analyzer...looked like a flea comb (ask the guy that bet his wife's cat
chow, oop's cat's chow, sorry) when it was oscillating.

Murray
-----Original Message-----
From: Gary Harmon <gharmon at IDWORLD.NET>
To: HEATH at LISTSERV.TEMPE.GOV <HEATH at LISTSERV.TEMPE.GOV>
Date: Sunday, March 14, 1999 6:44 PM
Subject: SB-104A 10 Meter Problem


>OK your experts, listen up because here's a strange one (not Keith but the
>problem or maybe both).
>
>
>Keith says:
>
>"I have probed this thing off and on for some time now, and am
>baffled.  I have put in known good boards from the other one, and it still
>does
>the same thing.  This would indicate to me the problem is not on one of the
>plug-in boards, but there doesn't seem to be anything not on plug-in boards
>that
>could possibly cause this problem.  Obviously, it's in some circuit
>involving 10
>meters only, but all of these types of circuits are on boards.
>
>What I'm getting is birdies that sweep the band.  They are loudest when you
>release the PTT after going to the transmit mode, and slowly abate, but
>never
>completely go away.  In transmit mode, a watt meter on the output will show
>110
>watts output on all four 10 meter ranges, yet no carrier can be heard in a
>nearby receiver.  I can hear myself when I speak into the mike and turn up
>the
>mike gain, but I think that it is the driver I'm hearing and not the final.
>Also, if you push the PTT button on the mike, it shows the same 110 watts
>output.  Of course, on the bands where it's working right, no output shows
>until
>you speak.  I guess that should tell me something, but it hasn't yet.  I've
>checked voltages and have run thru the entire alignment procedure for the
>working bands, and everything is kosher until you hit ten meters."
>
>What do we have here fellow Greenies???
>
>Thanks in advance,
>Gary
>
>
>Go Spurs!
>========================
>Gary H. Harmon, Jr. - K5JWK
>6302 Robin Forest
>San Antonio, TX 78239
>(210) 657-1549
>gharmon at idworld.net
>=================
>
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