[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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