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TH-D72 Sat Setup

jcalbano

Member
Jun 25, 2010
9
0
11
Lake Forest, CA
I have never communicated with a sat before.

I think I have to set the TX on the B Band and enable Full Duplex. Then, set the A Band to to the RX with several locations to compensate for doppler.

As the Sat passes, it looks like I have to switch back and forth A/B to communicate. Is this how it is done? Do I have the setup correct?

If anyone has set this up, please reply to the posting. Thanks for the help

JOHN
N6TRC
 

I have never communicated with a sat before.

I think I have to set the TX on the B Band and enable Full Duplex. Then, set the A Band to to the RX with several locations to compensate for doppler.

As the Sat passes, it looks like I have to switch back and forth A/B to communicate. Is this how it is done? Do I have the setup correct?

If anyone has set this up, please reply to the posting. Thanks for the help

JOHN
N6TRC

Sounds like you have it right. I have 6 memories programmed for each FM sat, 5 for the RX with doppler corrections and one tx. The A side is supposed to have the better sensitivity so I use that for RX. I hope to have my speaker mike with the 3 programmable buttons tonight. I plan on programming one button for A/B and the other 2 for memory up/down. AO-51 is hard to copy now because it is low power on the 435.300 and they are also running a downlink on 2.4GHz.

It might take a bit to get used to switching to the A side to change RX freq and then going back to the B side to TX but it seems to be the only way that works.

You may want to check for posts by WD9EWK on the Amsat BB archives: AMSAT-BB Archives
Then again, he is a member here and may reply
 
How to setup Sat TH-D72

Here is the reply I got from your recommended source.

Also, thanks for your reply.

JOHN


Hi!

> Trying to understand how to setup the D72 to communicate with
> AMSAT AO-15.
>
> I was going to put the TX on the A Band and the RX on the B Band
> then enable Full Duplex. But this does not appear to be working
> as I'll have to switch between A and B and the satellite passes.
> Maybe I have this all wrong.
>
> If anyone knows how to set this up, please reply to the message.
> Thanks for the help...never tried to communicate with a satellite
> before.

The TH-D72 will work cross-band full-duplex for satellites, but
you must transmit from VFO B and receive on VFO A. I have heard
that you could transmit and receive from either VFO with the
TH-D7, but Kenwood has limited this to the single arrangement
in the TH-D72. If the active VFO is VFO A, you will not see
"DUP" on the display to indicate full-duplex operation. If VFO
B is active, and the frequencies in each VFO are not on the same
band, then you can activate the DUP mode and see that on the
display.

The transmit frequency in VFO B should not need to change during
a satellite pass, but during the passes you will need to switch to
VFO A and then tune down 5 kHz to the next lower frequency every
couple of minutes, then switch back to VFO B so you can transmit
up to the satellite. All of our current FM satellites use a 2m
uplink frequency and a 70cm downlink frequency. The satellites'
receivers are broad enough to compensate for the Doppler effect
on your 2m transmissions up to the satellite, but you have to
adjust the 70cm receive frequency to deal with the Doppler effect
on the satellites' signals.

Make sure to have something take the place of the HT's speaker to
monitor the satellite. Otherwise your transmissions will cause
audio feedback - not a good thing. Use a headset/mic, or a
speaker/mic with an earpiece plugged into the speaker/mic, or just
plug earphones or an earpiece into the speaker jack on the side of
the radio. You, and anyone else listening on a satellite pass,
will appreciate the effort to avoid the audio feedback squealing.

I have worked AO-27, AO-51, and SO-50 with my TH-D72A. I missed
out on working HO-68 last week with my TH-D72A when it was in FM.
I was operating from a rare southern Arizona grid (DM31) on
Saturday, and decided to use a 2m/70cm FM mobile radio for my FM
satellite operating instead of the 5W TH-D72A. HO-68 will be back
in the FM mode starting on 26 December, and I will make time to
work that satellite with the TH-D72A during that week.

This is a very nice radio for FM satellite work. If you'd like,
please e-mail me directly and I can continue this in more detail
off the list.

73!

Patrick WD9EWK/VA7EWK
WD9EWK/VA7EWK
 
Yep, that's right on the money. You have to get used to changing to VFO A, adjusting the RX frequency and then back to VFO B to transmit.
 

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