My first instinct would be to try some different tubes and make sure you're
making the measurement with sufficient decoupling...
73...Jordan VE6ZT
----- Original Message -----
From: "Barry Scott" <[email protected]>
To: "Larry Haney" <[email protected]>
Cc: <[email protected]>
Sent: Saturday, November 09, 2024 3:13 PM
Subject: Re: [R-390] R-390 (non-A) - Low RF Gain or bad Antenna relay?
Larry,
Your document prompted me to check the three oscillators in my R390/URR.
On page 46 of TM 11-5820-357-35, the expected voltages of the three
oscillators is defined as being -3v to -11v. I just checked those and
the 1st oscillator is probably good enough (~ -4.8v) but the 2nd
oscillator and the PTO are both quite under spec.
I had scoped the outputs several months ago and I thought they were
stronger than that (or, at least, good enough) but checking just now
while in STANDBY with the VTVM tells a different story. Looks like I
have work to do.
Thanks,
Barry - N4BUQ
On Thu, Nov 7, 2024 at 2:21 AM Larry Haney <[email protected]> wrote:
Jerry, Because I found many different 'specs' for the oscillator
voltages
in the A, I wrote a doc about it. The 390 voltages should be very
similar to the 390As in my doc: R390A Oscillator Output Level Affects
<https://www.r-390a.net/R390A%20Oscillator%20Output%20Level%20Affects.pdf>
.
Regards, Larry
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