[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

RE: Handheld for Echo and FM Sats?

At 09:24 AM 7/8/2004, Mac wrote:
>You can rx and tx at the same time on the FT-50R? Slick trick, tell me
>how..I have missed something...

... Apparently ...

I don't have the rig with me; I am at work :-)   I do however have a copy 
of the manual on this computer.

Bear with me, as I am writing this while jogging my memory, and I am in 
dire need of defragmenting!

First, you don't operate the FT-50 in full duplex mode while using the 
VFOs.  Instead, you program in pairs of frequencies, using a non-standard 
split.  I cut the following table from my  "A Concise Guide to Working the 
Easy Sats, by KF4FDJ," which you can find in the AMSAT archives at: 

The paradigm applies to every FM bent pipe bird, just extrapolate the 
proper frequency pairs using the same logic as far as Doppler rates on 2 M 
and 70 cm.

Here is the table:

You should program your HT with 5 frequency pairs for working AO-27.
Start with the first pair, using a non-standard split, and tune to the
next one as the pass progresses.

Downlnk -  Uplink
436.805 - 145.845
436.800 - 145.850
436.795 - 145.850  middle of pass
436.790 - 145.850
436.785 - 145.855

The Doppler shift on the 70-cm downlink can be a little more than 10
kHz.  The 2-meter Doppler is close to 3 kHz.

I seldom need to use the 5th pair, except on high passes, and only when
the TEPR keeps the bird on so far south like it is operating presently!

... end of table

OK, so now you can plan the proper frequency pairs, right?

So, according to the FT-50 manual, here is how I programmed each pair.  I 
am retyping exactly what the book says:

Page 28 of 61 (in the PDF)

Custom Tx Offset

All memories can store an (sic) non-standard tx offset, for operation on 
repeaters with non-standard shift.  To do this:

Store the receive frequency using the method already described under 
Simplex Memory Storage (any repeater offset will be ignored).

Tune to the desired transmit frequency, then press and hold FW for 1/2 
second to display a slot at the right.

Press and hold the PTT switch while pressing FW momentarily (this does not 
key the transmitter).  Or (sic) course, if you're storing this in the HOME 
channel, you press 9BEEP when holding the PTT).

When a separate transmit frequency memory is displayed, +- appear at the 
top left corner.  You can press RVHM to display the transmit frequency, -+ 
blinks while the pair are reversed.

And on p 23 of 61, I find these words:

You are not limited to V/V or U/U operation; you can mix VHF and UHF VFO 
channels for cross-band semi-duplex operation!

I can tell you this: my Yaesu FT-5100 mobile is capable of cross band 
repeat, but the FT-50 is not.  However, you can transmit on VHF and listen 
on UHF (or vice versa) with the FT-50 in FULL DUPLEX mode.

73, Mike kf4fdj

Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org