[Drake] R4C Low sensitivity
DJED1 at aol.com
DJED1 at aol.com
Sun Feb 26 13:48:36 EST 2006
Scott
Your results seem just a little light compared to my similar R-4C
(6EJ7-type). I am just in the process of checking the alignment, but it looks like it
hasn't changed much since I last did it- so here's what I've got: My radio
calibrator reads S9 +5 on 10M, increasing as I go down to 80 M. However, I've
got the meter set a bit high to compensate for lower gain when I use the PTO
in the transmitter. So my radio reads S9 +5 for a 30 microvolt input, not
the S-9 the factory recommends. So maybe you're one S unit low if you have
already set the S-meter per the manual. Have you checked the absolute level
for S-9? I don't know how repeatable the calibrator is. All in all, still a
great rig for SSB. I was amazed at the sensitivity of the radio- it can read
signals that don't even move the S-meter.
PS I di have some problems a couple of years ago with lowered gain- it
varied with time and temperature. Finally traced it to a bad gain pot on the
noise blanker board. Replace the pot and all has been very stable.
Ed
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