----- Original Message -----
From: "joel hallas" <jrhallas@optonline.net>
Folks,
I seem to have a new problem with my Paragon. It transmits spurs 600 Hz
above and below the carrier about 10 to 20 dB down from the carrier.
This was reported to me by someone using the spectrum scope on an
SDR-1000. I have confirmed that at least one is there on another
receiver and the level seems about right. I can also notice the effect
on strong receive signals. I thought it was them <g>!
I will put it on the spectrum analyzer at work next week, but wondered
if this is a known problem? I have done the "routine" things like
tighten all board screws and reseat all connectors and master reset.
Any thoughts?
Thanks!
Joel Hallas, W1ZR
Joel,
What was the input voltage to the Paragon? I think it
maybe sensitive to input voltage. Before I retired it,
I ran mine off of a 13.8V supply and never had any
complaints about my TX purity, nor did I notice any
spurs on receive (-40dBc spurs would surely manifest
reciprocal mixing products with strong signals which
I never saw in practice). When I put it on a spectrum
analyzer, however, it looked horrible:
http://www.dellroy.com/W4EF's-Ham-Radio-Page/Paragon/paragon_tx_spectrum.htm
I never resolved the discrepancy, but in thinking
back, I may have carelessly run the spectrum
analyzer test at 12.0V input instead of +13.8V.
I know that my Omin 6+ just plain doesn't work
at 12.0V (it needs +13.8V) and I suspect that
the Paragon may have similar issues. I had intended
to re-run the test with a variable supply, but I
just haven't had the time (not much incentive since
I am not using the Paragon currently).
In any case, I would start with supply voltage
and go from there.
73, Mike W4EF..........................................
|