[amsat-bb] HT for sats

Patrick STODDARD (WD9EWK/VA7EWK) amsat-bb at wd9ewk.net
Thu Jan 25 18:50:06 UTC 2018


"(O)n current HTs"? Other than some reports I have seen about
the Alinco DJ-G7T and its poor receiver for FM satellites in
general, it appears that the HTs that have been previously
reported as capable of full-duplex operation with V/U FM
satellites like AO-51 and SO-50 would be fine with the mode
B (U/V) satellites like AO-91 and AO-92. With the uplink on
70cm, you avoid issues with harmonics which can be an issue
on some radios capable of full-duplex operation when you
transmit on 2m - keeping in mind that frequencies in the
435-438 MHz satellite subband can be very close to the third
harmonic of the 2m uplink frequency.

After AO-85's launch in October 2015, I tested a few Chinese-
made 2m/70cm FM HTs that were advertised as being capable of
full-duplex operation. None of them could work SO-50 full-
duplex due to receiver desense, but could be used with AO-85.
I wrote a series of AMSAT-BB posts about those tests at that
time, and a link to a summary with other links to the specific
models is in the AMSAT-BB archive:


I have been using the Wouxun KG-UV9D with AO-91 on a regular
basis, either with my Elk log periodic or an MFJ-1717 2m/70cm
long duckie. This radio, along with other HTs like my TH-D72
and an old TH-D7 I had for a little bit, is capable of full-
duplex operation with mode B (U/V) satellites. I have seen
other reports online of hams using a Wouxun KG-UV8D (or one
of its variants) to successfully work AO-91 full-duplex.


Twitter: @WD9EWK or http://twitter.com/WD9EWK

On Thu, Jan 25, 2018 at 6:30 PM, John Geiger <af5cc2 at gmail.com> wrote:

> Does desense on 2m occur with using Mode B FM satellites in full duplex on
> other current HTs?
> 73 John AF5CC

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