Hello Roger and Laurence,
The '817 that I'm using is quite stable without the tcxo. I've used it
for receive only and found that it stayed on QRG within 0.1 Hz for several
hours on 137 kHz. Perhaps the heat from the TX is causing drift.
The sensitivity on 137 is not so good as we all know...
73
Joe VO1NA
On Sun, 3 Feb 2013, Laurence KL1 X wrote:
Roger - I had the same drift issue and added the txco with little improvement -
best was when unit was powered driven by lower voltage - think mine is set
around 9.6V at the moment and less heat..it also sits in the cool
garage...think Dex also found the same
Laurence KL 1 X
Date: Sun, 3 Feb 2013 19:23:35 +0000
From: [email protected]
To: [email protected]; [email protected]
Subject: LF: WSPR15 - sort of success
After several attempts Tom G8HUH managed to decode my WSPR15 transmission on
137.607kHz this evening. As the FT817 was drifting around 4Hz in the 15 minute
TX slot with the FT817 on 1837.607kHz (I was using a stabilised sig gen for the
LO at 1.7MHz), I think this was messing up the decodes as Tom only gave me -32
and -34dB S/N whereas I have been getting some 6dB BETTER than this with the
WSPR2 transmissions.
If WSPR15 is going to succeed for me I need a more stable rig (or a 0.5ppm TXCO
fitted to the FT817) or a fan to force cool the FT817 - even when running 500mW!
I'll leave the rig on for a little while longer, but will probably revert to
WSPR2 for the rest of the evening.
Thank you Tom G8HUH, and Trevor G0KTN, for working with me for the last couple
of hours to get this as good as I could.
73s
Roger G3XBM
--
http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
https://sites.google.com/site/sub9khz/
http://qss2.blogspot.com/
http://www.youtube.com/user/G3XBM
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