Hello Paul,
Perhaps consider getting one of the cheap Fox TCXO's? I use them in
U3S and they work great with GPS from a QLG1. They are a bit fiddly to
solder until you realise they aren't as delicate as they look and you
put four solder blobs on the PCB pads and on the pads of the Fox, then
fuse them together with a hot iron going around all four in
successionm rapidly. I have even used a crude hot air pen (gas
soldering pencil torch with the hot air tip on it) to remove and re-use
one from a dead board. I was amazed it survived the experience but it
was just as good as a new one! 2E0ILY
Thursday, November 2, 2017
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I am pleased to report I finally found time to "finish" my U3S
build. Well, almost. I haven't built the OCXO yet. Truth is, I
probably don't need it anyway since I have the QLG1 and will only be
using this on the low bands mentioned. When I start running QRSS I
will find out soon enough!
During the build I asked if anyone had thoughts on T1 for optimized
performance on these bands. There was no feedback. After fiddling
with a bifilar wound core trying to make it lay flat (to accommodate
the OCXO) and look nice I scrapped that and just went with a single
25 turn winding. I've just measured power output at 240 mW on 2200m,
260 mW on 630m, and 350 mW on 160m. I can live with that since I
will be using it to drive an outboard amplifier. My measurements
should be fairly accurate. I used a well calibrated oscilloscope to
measure voltage across a precision 50 ohm load. Since output is
lower on the lower bands, I suspect some optimization could be
done... either by going to the bifilar winding and/or substituting a
core of different material. At the moment I an not inclined to
pursue that.
73,
Paul N1BUG, WI2XTC
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2E0ILY
Best regards,
Chris mailto:chris@...
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Best regards, Chris Wilson (2E0ILY)
