Programing amateur satellites for Tx and Rx.

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Jhernan488

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Hey, what frequencies should I have programed forAO-91, AO-92, SO-50 for Tx and Rx due to Doppler shift. I was told not to worry about Tx Doppler shift.. what's the best way to program them? And do you just set a repeater shift? I'm confused on what shift to use as it goes from vhf-uhf-vhf. Or do you utilize A memory for Rx and B memory for Tx?
 

N4DJC

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Uplink uses the tone, how you program defends on the radio. Doppler is important on UHF up or down. What are you using?
 

royldean

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As stated, you will always have to tune for doppler on 70cm. Tuning for doppler on 2m is usually not necessary, but may be of use on some passes (to eek out the most of the pass with the best audio).

The tone is always on the uplink (Tx) frequency. If your transceiver allows it, you can program each satellite as a group of "split" offsets (meaning that the input - Tx - is on one band, and the output - Rx - is on the other band). Many radios don't allow for this. But more importantly, you will have much better success if you operate full duplex, meaning you are using either a full duplex transceiver (like a Kenwood D72 or D710G) or using a pair of cheaper transceivers (one on Tx, one on Rx). Do check out the AMSAT links as there is good info to be found. Also check out the satellite forum on QRZ.com and the AMSAT mailing list archive for more info than you probably want.
 

Jhernan488

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As stated, you will always have to tune for doppler on 70cm. Tuning for doppler on 2m is usually not necessary, but may be of use on some passes (to eek out the most of the pass with the best audio).

The tone is always on the uplink (Tx) frequency. If your transceiver allows it, you can program each satellite as a group of "split" offsets (meaning that the input - Tx - is on one band, and the output - Rx - is on the other band). Many radios don't allow for this. But more importantly, you will have much better success if you operate full duplex, meaning you are using either a full duplex transceiver (like a Kenwood D72 or D710G) or using a pair of cheaper transceivers (one on Tx, one on Rx). Do check out the AMSAT links as there is good info to be found. Also check out the satellite forum on QRZ.com and the AMSAT mailing list archive for more info than you probably want.
Okay thanks for the info. So if the uplink is 70 cm, you also have to tune to Tx?
 

royldean

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Okay thanks for the info. So if the uplink is 70 cm, you also have to tune to Tx?
Yes, absolutely. If you don't, depending on how far off you are, you won't get in at all - or you're voice will sound very choppy and sometimes unintelligible. Often times you will then hear other operators say "you need to tune for dopppler" or something like that.
 

N4DJC

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Okay, thanks. I have a uv5r and a ftm3d
The FT3DR is pretty easy to set up for S0-50.

AO-91 is a zoo during the daylight hours, it requires a good antenna and two radios or a full duplex rig. Being able to hear your own signal on the downlink is very important for either 91 or 92.
 

Jhernan488

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The FT3DR is pretty easy to set up for S0-50.

AO-91 is a zoo during the daylight hours, it requires a good antenna and two radios or a full duplex rig. Being able to hear your own signal on the downlink is very important for either 91 or 92.
I just ended up getting a cheap full duplex HT to try it out. It's the kguv8d. I have heard good and bad about it. But I'll see how it works.

I have the duplex arrow antenna.

Yeah, they are definitely a zoo during daytime hours.
 
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