Actually, I just use the VFO on my D7A as well. ;-)
As far as stepping on someone, it is going to happen on a single channel satellite, just make sure it is not deliberate. Listen, if no one is calling or in the middle of a QSO, jump in! Don't be afraid to throw your call out.
Another thing that you should definitely consider - full duplex. In case you don't know what this is, full duplex is simultaneously listening to the downlink WHILE transmitting. This prevents a lot of useless QRM. When you call, you can not only tell if you are stepping on someone, but you can hear how good/bad your uplink signal is, and you can be sure that you are getting through and not just getting stepped on. You are even ahead of the game - the TH-D72A has this feature! All you need to do is learn how to use it. You may, however, want to try a few more passes before diving into full duplex. Full duplex will not do you any good if you have trouble hearing or tracking the birds.
73!
Zack KD8KSN
-----Original Message----- From: Alexander Sack Sent: Monday, May 16, 2011 5:45 PM To: Zachary Beougher Cc: Clint Bradford ; Clint Bradford ; amsat-bb@amsat.org Subject: Re: [amsat-bb] Re: Fm satellite Frequencies and Doppler
On Mon, May 16, 2011 at 5:25 PM, Zachary Beougher zack.kd8ksn@hotmail.com wrote:
Alexandar,
I am not sure how you have it programmed into the radio so far, but I would program 5 memory frequencies into your HT:
(AO27)
436.805 (AOS) 436.800 436.795 (TCA - Time Of Closest Approach) 436.790 436.785 (LOS)
Since AO27 switches off way before LOS, you will probably never need the last frequency - 436.785 - but these would be the common frequency steps for a typical bird like AO51, SO50, etc. Don't be afraid to make adjustments either. I find that to hear the 30 sec. of TLM right before AO27 switches to VOX I have to be at 436.810. This is probably more a feature of the radio itself. If you are having trouble hear at AOS or LOS, try adjusting your downlink by 5kHz.
You can also add alpha-numeric tags to your frequencies to keep them in order:
AO27-1 AO27-2 AO27-TCA AO27-4 AO27-5
There are many different variations you can choose from.
Let me tell you what I have been doing:
I have programmed my TH-D72A with the TCA as a base. I switch to it then move it to my VFO (F+VFO). When the bird is going to approach, I instantly go up 10Khz and work from there. Its actually ridiculously easy to just switch down via the tuning knob (so programming above doesn't really buy you much). Typically depending on the bird's doppler, I wound up finding the signal a bit lower than 10khz up (its not like my AL-800 instantly picks up the signal at 5 degree elevation) but when it does, I'm good for the remainder of the pass.
The AO-51 FAQ page spells it out very nicely. Knowing the polar chart in your head for the pass is very helpful. It allows you to gracefully move with the signal as the satellite passes over you.
My biggest issue right now is knowing when to call out. The flurry of folks calling CQ on each pass where I live (FN20) makes it very hard to either a) not step on anyone and b) even find a window to get in. I will keep trying though (maybe when the weather gets a bit better on the East Coast).
73
-aps