[hpsdr] Excalibur Issues

[Graham / KE9H]

Jeremy:

The warbling you are describing is usually the result of driving the Atlas
bus with multiple 10 MHz frequency sources.  Are you sure that you have
turned off both Mercury and Penelope 10 MHz output to the bus?

The fact that the warbling goes away when you turn off Excalibur would be
consistent with two drive sources.

Do you have an oscilloscope that you can look at the 10 MHz line on the
Atlas bus with?

As far as having a bad TCXO, that is possible, but I have not seen one 
of them
fail that way, so far.

--- Graham / KE9H

==

On 11/10/2010 2:19 PM, Jeremy McDermond wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> I was working on some improvements to Heterodyne in the past couple of days, and noticed a significant warble to signals when I switched to SSB mode on the ham bands.  It's something that I could both hear (which made conversations unintelligible), and see on the waterfall (you could see what were supposed to be constant tones looking like sine waves).  I narrowed the issue down to Excalibur.  When I have it pulled, signals are okay, but when it's in the system, I get the warbling effect.  For fun and games, I set the Excalibur jumper to "external" without anything hooked up, and the warbling went away.
>
> I took my MFJ-259B with a length of RG-58 cable stripped on the end to expose ground and signal (I know, not a real precision instrument) and measured the frequency at TP2 (the output of the Crystek), and was measuring 50 MHz.  I'm wondering if I have a bad TCXO, or whether folks maybe have other ideas (cue making fun of the software guy).
>
> --
> Jeremy McDermond (NH6Z)
> Xenotropic Systems
> mcdermj at xenotropic.com
>
>
>
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