[eagle] Re: Going into the deep Echo archives.
rwmcgwier at gmail.com
Tue Sep 4 02:49:31 PDT 2007
Tom Clark, K3IO wrote:
> Bill Ress wrote:
>> If I read the Excel spreadsheet correctly, if says that -100 dBm into
>> the SQRX at 28 Mhz was full quiting??? Is that directly into the coupler
>> you installed?
> Lyle should verify for sure, but I believe it is into the 2M whip's SMA
> on the "top".
>> Any idea what signal is needed at the 18" whip at 28 MHz to provide a
>> usable signal from the SQRX in the SSB mode? You know were I'm going
>> with this, don't you? Or have I lost the bubble here and that mode has
>> already been tried??
> Remember that the 18" whip is pretty short at 10M. The equivalent
> circuit is a capacitor and a radiation resistance that can be more than
> an ohm. So the sensitivity is quite low.
CAN NOT BE more than an ohm. I am sure the intent was clear but just
wanted to make sure.
> Yes, it has been tried in SSB (i.e. linear receiver), mostly for some
> PSK31 tests. PSK31 signals (at whatever doppler is applicable) would
> them modulate the NBFM xmtr. So you tune your favorite PSK31 demod on
> the noise output from your 70cm rcvr. Downlink doppler is irrelevant.
> Drew/Gould should offer comments, but I believe some signal were copied
> by no QSOs made. The stations were (as I recall) running ~100 watts out
> from a typical HF xcvr.
> Again the problem is that the 18" whip is too short by a factor ~6.
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