[R-390] COSMOS PTO EP ADJUSTMENT

[Shoppa, Tim]

That would be taking what is perhaps one of the lowest phase noise PTO's ever manufactured, and replacing it with the cacophony of digital circuitry. I don't see the point. And after you're all done you would still have the 17MHz oscillator pulling under AGC action (a weak point of the 390A that occasionally bothers me).

An unobtrusive low-noise (even better, no noise!) frequency counter replacing the veeder root and the window, used with the existing PTO, that I could see. Wouldn't do it, but I could see it. It would change the knob feel because there wouldn't be the slap-slap-slap-slap as the decades whip by in the veeder root... for some this would be a loss, maybe for others a gain.

Tim N3QE

-----Original Message-----
From: r-390-bounces at mailman.qth.net [mailto:r-390-bounces at mailman.qth.net] On Behalf Of Barry
Sent: Wednesday, April 21, 2010 1:34 PM
To: r-390 at mailman.qth.net
Subject: Re: [R-390] COSMOS PTO EP ADJUSTMENT

I wonder if anyone has attempted to replace the PTO with an encoder-drivern LO?  Yeah, it's "heresy", but it sure would put an end to endpoint and linearity problems...

Barry - N4BUQ

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