[amsat-bb] AMSAT-BB Digest AO-51 & SO-50 Yaesu VX-7R

ki6rrq ki6rrq at cox.net
Sun Dec 7 14:49:29 PST 2008

I am currently using a Yaesu VX-7R (not the best for satellites, also using
it because that's what I had)for the ISS and the FM birds.   I don't know if
this will help anyone but I found using the memory tune feature is very
helpful for working the Doppler, I don't know if your TH-F6A or many other
HT's have it but I think it saves me a little time and hassle, when the
receive frequency is on 2 meters, anyway.  I know the FT-60's have it too.

For AO-51, I save a memory channel with the 2 meter receive freq and then
add the odd split or odd band split to the TX part of that memory and the pl
where appropriate ...  Then when I use it out in the field on my Arrow II, I
bring up the memory and then select the memory tuning mode, which I guess is
similar to the VFO mode but keeps the TX side in place and allows me to tune
the RX frequency up and down to adjust for the Doppler and all I have to do
is push the PTT when I make my call and the 2 meter TX frequency is
automatically used.  I don't even have to hold the radio, just get my
fingers to the dial tuning knob, a few times during the pass.  (tripod
mounted radio, per my qrz.com)    I haven't found its worth worrying about
the Doppler on the 2 meter side, since the radio only does 5k at a time.
After trying numerous methods, I found this to be easiest, with everything
else you have to deal with on a mobile sat. operation; writing calls down,
keeping the antenna on the bird, testing for polarity alignment, dealing
with the dark, oh yea what was that guys call again... Its like an Apollo 13
rescue mission to get it all done... except its always a fun ride... LOL, I
needed to simplify everything. 

Best Rich KI6RRQ  


Message: 2
Date: Sun, 7 Dec 2008 13:42:01 -0500
From: "Jim Leder" <k8cxm at fuse.net>
Subject: [amsat-bb] Re: Kenwood TH-F6A for AO-51 / SO-50??
To: "Amsat" <AMSAT-BB at amsat.org>, "Guy Brauning"
	<guyjeanbraun at comcast.net>
Message-ID: <547D1F8574B04DDC801A1FD71EB224FE at Toshibalaptop>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";

I have used my Kenwood TH-F6A along with an Arrow antenna, and IMHO it works

just fine. You do need to get it programmed right and you need to get used 
to switching between VFOs as you track the satellite and the Doppler effect 
on frequency. It is NOT a full duplex radio like the W32A, and you will not 
be able to hear yourself, but I have never felt that's been a problem.. I 
programmed mine to transmit on one VFO (uplink) and be able to receive on 
several different frequencies (downlink) on the other VFO. On the transmit 
VFO, the squelch is closed all the way, while on the receive VFO, it's open 
all the way. So, VFO A is set for uplink of 145.920 on memory channel 150 
and on memory channels 152-153 I have them programmed for 435.290 and 
435.295 (downlink which is in VFO B). 154 is center frequency of 435.300 and

of course 155 and 156 are set to 435.305 and 435.310. By switching between 
VFOs I can change downlink channels/frequencies to fit the Doppler shift. A 
little cumbersome, but that little radio works very well. You can follow a 
similar scheme on the QRP channel of AO51 (mine is 160-166) and SO50 (mine 
is 170-176-get the picture). I have made several contacts with it on the QRP

channels but have had no luck on SO50, which is a lot more difficult 
satellite to hear.
 I'm using it because it's what I had, and I'm happy to say with a little 
use and practice you quickly get the hang of it.
 Of course, either the W32A or the Kenwood TH-D7A do FULL duplex, but both 
are no longer in production. Hearing yourself is nice, but not necessary.

     Jim Bob Buckeye
  **** Jim Leder****
    K8CXM since 1961
 IBM retiree since 1999

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