[amsat-bb] Re: Operating question: FT-736r and HO-68/VO-52

Greg D. ko6th_greg at hotmail.com
Sun May 30 22:52:11 PDT 2010

Hi Bill,

So, filling in more of the puzzle...

The purpose of the NOR and REV positions of the SAT knob are to set how the rig tracks the Receive and Transmit sides of the rig.  This is a great help when tuning around the satellite's passband, looking for a QSO in progress or someone calling CQ.  

As you know, the Rx setting controls the receive side of the rig, and Tx controls the transmit side, and the earlier email talks about how to adjust them to "find yourself".  You can, of course, just twiddle the Receive side of the radio and scan the band, but then when you find something to participate in, what about the Transmit side?  All that work you went through to find yourself was destroyed the moment you changed frequencies.  Now you have to find yourself all over again, taking time, potentially interrupting the QSO, or missing the CQ.  Wouldn't it be nice if the transmit and receive sides were locked, so that moving one would move the other as well?  That's what the NOR and REV settings are for.

In NOR mode, increasing one side, moves the other an equal amount in the same direction.  This is for satellites that are "non-inverting" (of which we currently have none).  These satellites use the same sideband on both uplink and downlink, and increasing the frequency of the uplink moves the corresponding downlink up the same amount.  So, you can see that the NOR setting will allow you to move the receive side of the rig around, and the transmit side will follow.  Then when you find something to do, you're ready to go!

The REV setting is used for Inverting transponders.  Increasing one side results in a decrease in the other, again matching what happens with your signals through the satellite.

So, use the Rx and Tx settings to find yourself in a quiet part of the band, then flip to NOR or REV, depending on the satellite, and tune around for some activity.

One final note...  Because the Doppler shift is a function of frequency, the shift that gets applied to the uplink and downlink are different.  This means that over the course of the satellite's pass, the magic combination of uplink and downlink where you found yourself at the beginning of the pass will drift apart.  This means that periodically you will need to temporarily move off of NOR or REV mode, back to Tx or Rx (which ever is on the higher band) to refine your settings. It's a bit annoying, but you get used to it.

Hope this helps.  Good luck!

Greg  KO6TH

> Date: Sun, 30 May 2010 12:28:55 -0700
> From: mrcyberbill at yahoo.com
> To: amsat-bb at amsat.org
> Subject: [amsat-bb]  Operating question: FT-736r and HO-68/VO-52
> Operating question: FT-736r and HO-68/VO-52
> Hello:
> I have a Yaesu FT-736r and I am wondering the proper way to set a few switches for the CW/SSB satellites HO-68 and VO-52.
> I can set my transmit and receive in the middle of the uplinks and downlinks for these 2 satellites.
> - then- 
> For these 2 satellites (2m-440) (inverting) how do I set the NOR/REV switch? and the USB/LSB switches for the 2 frequencies? A general rule for uplink freq and downlink freq (USB/LSB)??
> (Trying to get it right - from the beginning...)
> Thanks, Bill 
> -  billwest007 (at) yahoo (dot) com
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