As a benchmark, I want to try first with the original design, then swap crystals but without the toroid near the crystal. I should be able to net the crystal without the toroid.
The simple direct conversion RX uses a Polyakov mixer with injection at half fequency.
See https://sites.google.com/view/g3xbm4/home/hf-mf-and-lf/homebrew/10ft8r-rx .
UPDATE 1400z: As expected, the even simpler circuit around the crystal works fine with plenty of South American stations immediately spotted. The map shows the stations spotted in just the last 30 minutes on the 10FT8R with the simpler circuit (no toroid) and a 14.037MHz crystal. It works. The revised circuit is shown on the photo, without the crystal T50 toroid.
UPDATE 1746z: 193 stations spotted on 10m FT8 RX with the 10FT8R. It looks like the propagation is now stopping as darkness falls.
UPDATE 1911z: QRT. No more stations for some while now.
6 comments:
Yes, there’s quite a bit of activity on 10m FT8 this afternoon.
What a BORING post!
Try a 20.330MHz crystal for 40.662 WSPR/FT8!
Cybernet CB radios use them.
Thanks Robert. That's an idea if I get a permit for 8m TX.
An interesting spread of stations copied here on 10m FT8 this afternoon. They extended from Norway in the north to Antarctica in the south, and from Indonesia in the east to North and South America in the west. What would be your best guess on propagation modes(s)?
Some F2 and some Es.
That confirms my thoughts. I just wondered if you thought some other mode such as TEP might be there because of the wide geographic spread.
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