[amsat-bb] Wouxun KG-UV8D

[Patrick STODDARD (WD9EWK/VA7EWK)]

Hi Craig!

As N8HM mentioned, I have tried the KG-UV8D on SO-50. It will not work
for cross-band, full-duplex operation on this satellite.  Using a group
of memory channels, its receiver is OK for hearing the downlink when
working SO-50 half-duplex, or as a receiver when transmitting with a
second HT (even one of the cheaper Baofeng HTs!). There has been a long
discussion thread about this radio on QRZ.com's satellite forum at:

http://forums.qrz.com/showthread.php?437813-Wouxun-KG-UV8D-for-SO-50-Sure-but-not-full-duplex-by-itself

Like with many Kenwood and Yaesu HTs, you can program a group of memory
channels to work SO-50 half-duplex. Make sure to set up the memories
where the receive/output frequency steps down in 2.5 kHz steps. Otherwise,
there are times, around the point you would change receive frequencies,
where you won't be able to hear the satellite on either frequency when
tuning in 5 kHz steps (i.e., from 436.800 to 436.795 MHz).  All versions
of this radio with firmware at V1.02 or greater tune in 2.5 kHz steps,
so this means you'll end up with twice as many memories for working
SO-50 than with other radios incapable of tuning in steps smaller than
5 kHz.  (To view the firmware version in a KG-UV8D, press and hold the
3 key while turning on the radio)

Beyond SO-50, the KG-UV8D will work OK for V/U cross-band full-duplex
operation, if the 70cm signal you're trying to hear is a lot stronger
than the SO-50 downlink. The receiver is certainly better than the
Alinco DJ-G7T 2m/70cm/23cm HT - another one that was promoted for
cross-band, full-duplex operation a few years ago.  I find myself
grabbing the KG-UV8D more often when I want to have an HT with me,
unless I'm looking to do APRS using a TH-D72A instead.

While at the ARRL Centennial Convention in Hartford a couple of weeks
ago, I did a test with my KG-UV8D and the Fox-1 prototype on display
at the AMSAT booth. The Fox-1 series of satellites (remember 3 have
launches - go AMSAT!) are U/V satellites, the reverse of SO-50.  You
will transmit on 70cm, and receive on 2m.  In this configuration,
and making allowances in an attempt to better simulate working a
Fox-1 satellite in orbit, I was able to work the Fox-1 protoype
full-duplex walking around the main hall and just outside the hall.
I varied my transmit power between high and low, and moved my antenna
around, trying to change how the received signals sounded as I
transmitted.  The Fox-1 prototype used a dummy load as an antenna.
I was able to hear myself without any noticeable desense at either
transmit power level, even when the Fox-1 prototype's downlink
started to sound as weak as SO-50 typically does.  I received good
signal reports from Burns W2BFJ, a member of the Fox software team
at the AMSAT booth who listened to some of my tests.  This gives me
hope that the KG-UV8D - and other radios like the newer versions of
the IC-W32A - might work for cross-band, full-duplex operation with
U/V satellites like the upcoming Fox-1 series, when they don't do
the same for V/U satellites like SO-50.

If you want to discuss this further, and the posts on that QRZ
forum thread didn't answer any other questions you might have about
the radio, please feel free to contact me directly.

Good luck, and 73!





Patrick WD9EWK/VA7EWK
http://www.wd9ewk.net/




Has anyone tried one of these for portable use ? It has cross band repeater
> and also functions in Full Duplex.
>
>