[GreenKeys] Space diversity receive antenna

[Nick England]

Larry W1SIM regularly uses space diversity reception on our Saturday
morning 40m 850 shift RATT net.
He gets very good results using a vertical and a horizontal antenna and
often comments about watching the strength shift between the two.
I think he uses a pair of ST-8000A TUs for this.

Nick England K4NYW
www.navy-radio.com


On Sat, Jan 4, 2025 at 12:30 PM Harold Hallikainen via GreenKeys <
greenkeys at mailman.qth.net> wrote:

> I'm really having a problem with QSB. A received signal (20 meters) goes
> from great to down in the noise over several seconds. As an experiment, I
> transmitted both mark and space tones from here in Tucson AZ and received
> them on the KFS SDR in Half Moon Bay CA. I then ran the recorded audio
> into the DSP TU and output the levels of the mark and space filters. The
> results are at
>
> https://w6iwi.org/script/csvgraph.html?CsvUrl=https%3A%2F%2Fw6iwi.org%2Frtty%2FTuNotes%2Fms220517a.csv
> .
>
> This reminds me of a TV station where I lived in San Luis Obispo CA that
> had a long microwave feed. They put two receive dishes on their tower and
> had a carrier operated relay in the receiver start a slow astable
> multivibrator that switched the receiver input between the two receive
> dishes. The switching would stop when a good signal became present.
>
> So, how about applying this to RTTY? I am using a 30 foot vertical for
> transmit and receive. I could put up a 20 meters dipole about 50 feet
> away. During receive, I could switch between these two antennae.
>
> Is this worth trying? I could use signal strength indicated by the
> receiver. Or I could use something from the terminal unit (such as switch
> during mark hold).
>
> Is anyone using space diversity? Comments?
>
> Thanks!
>
> Harold
> https://w6iwi.org
>
>
>
>
>
> --
> Not sent from an iPhone.
> ______________________________________________________________
> GreenKeys mailing list
> Home: http://mailman.qth.net/mailman/listinfo/greenkeys
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:GreenKeys at mailman.qth.net
>
> >>> Jordan Spencer Cunningham's GreenKeys Search Tool:
> https://teletype.net/gksearch
> >>> 2002-to-present greenkeys archive:
> http://mailman.qth.net/pipermail/greenkeys/
> >>> 1998-to-2001 greenkeys archive:
> http://mailman.qth.net/archive/greenkeys/greenkeys.html
> >>> Randy Guttery's 2001-to-2009 GreenKeys Search Tool:
> http://comcents.com/tty/greenkeyssearch.html
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to navy.radio at gmail.com
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/greenkeys/attachments/20250104/dab673cc/attachment.html>