[R-390] R390 carrier level pot fix

[David Wise]

I misspoke, partly.  It's mentioned in the Pearls (Jun 2002, search for "R523"), but the actual 2007 article is in Y2K-R3 Chapter 11.  (Search for "Carrier Zero".)

Just today, as I reviewed it, an improvement occurred to me.  Better late than never.

Supplement to "R-390/R-390A Carrier Meter Zero Adjust Mod":

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If you need a low value of R537 to get 100dB, and this
makes it impossible to zero, you can increase the current in
R537, which will shift the zero-adjust range upward.
A neat way to do this is to lift R541 (270 ohms, V508 pin 7,
cathode resistor) off ground and run it to R537.
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73,
Dave Wise (SWL in Hillsboro Oregon)

________________________________
From: James Barrie [barrie at eos.net]
Sent: Tuesday, February 24, 2015 5:37 PM
To: David Wise
Subject: R390 carrier level pot fix

Where in the Pearl of Wisdom is it?
Tnx
73
Jim
WA8SDF