[R-390] R-390 : L903 in the Calibrator Module

[jgedde at optonline.net]

Hi Jacques,

I can't say it made any difference in how it worked...  I left the capacitor
alone.  I thought the cap increase could reduce output from the 1 MHz
oscillator.

Where did you read about the tubes having to be 5814A's?  I'd like to check
that out too.

John

-----Original Message-----
From: Jacques Fortin <jacques.f at videotron.ca> 
Sent: Thursday, June 13, 2019 10:14 AM
To: jgedde at optonline.net; r-390 at mailman.qth.net
Subject: RE: [R-390] R-390 : L903 in the Calibrator Module

Hi John,

Yes... 0.5µH for an oscillator running at 1MHz makes no sense (only 3.14
ohms of XL).
Have you also changed the value of C 905  (from 150 to 200 pF) ??
I also read yesterday that the V901 and 902 have to be 5814As, maybe to
better resist cathode poisoning (filaments on but no plate current most of
the time).
Is your calibrator working OK with L903 at 0.5mH ??

73, Jacques, VE2JFE