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

n3tl@bellsouth.net n3tl at bellsouth.net
Sun Dec 7 15:10:51 PST 2008


Thank you for posting this. I never thought to mention the Memory Tune feature, which is, indeed, very useful. Like you, I began using the VX-7R on the satellites because it is what I had at the time. I have no intention of trading mine until some company brings a new radio to market with full duplex capability. 

It permitted me to earn Satellite VUCC, all handheld, and the AMSAT Achievement Award - the latter using only 50 mW contacts (21 states, Mexico and Ontario) made on the same set of 2 AA Duracells. I also made four contacts through the ISS U/V repeater over the weekend with it. 

As you say, it may not be the best for the satellites. But it's more-than-good-enough for me.

Also, here's a tip that, I hope, you'll find to decrease your stress level on every pass. Get a small digital voice recorder that has a time counter, and just record your passes - even if it's just the wild sound. I have done that since Day 1 with a small recorder I can clip to my shirt collar or pocket. I don't worry about writing down calls at all. I start the tape on an even minute (e.g., if my AOS is at 23:15:12, I start the recorder at 23:12:00. I speak that time into the condenser mic, and include the satellite I'm working. After the pass, I just come in and replay the tape, which allows me to synch calls and times correctly for logging purposes. It also gives me a chance to MP3 clips from contacts I want to keep. The "wild sound" quality isn't as good as having a full duplex radio and having the recorder connected to the audio out jack, but it's the only way to get boths sides of a contact since the VX-7R operates only semi-duplex.

73 to all,

Tim - N3TL
AMSAT Member No. 36820
QRP-ARCI Member No. 5547
ARRL Member No. 7027180
Athens, Ga. - EM84ha
-------------- Original message from "ki6rrq" <ki6rrq at cox.net>: -------------- 

> 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" 
> Subject: [amsat-bb] Re: Kenwood TH-F6A for AO-51 / SO-50?? 
> To: "Amsat" , "Guy Brauning" 
> Message-ID: <547D1F8574B04DDC801A1FD71EB224FE at Toshibalaptop> 
> Content-Type: text/plain; format=flowed; charset="iso-8859-1"; 
> reply-type=original 
> 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 
> AKA 
> **** Jim Leder**** 
> K8CXM since 1961 
> IBM retiree since 1999 
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