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Re: Tune the uplink or downlink?



Ciemon,

Just to avoid confusion, following Walter's reply and another one from
another poster, you _can_ get away without tuning your uplink. I've found it
handy to have the ability to tune uplink too on occasion though, probably
because my TX may be a Khz or two off frequency already.

What we're trying to do is match our uplink to be in the FM passband at the
sat.

The downlink's easier to tune, because you can already usually hear someone
chatting away. The uplink's a tad more tricky. Again, this is where a bit of
practice holds the key.

But, like I said previously, you can get away without tuning your uplink,
but having the option's always handy.

73 Howard G6LVB

----- Original Message -----
From: "Howard Long" <howard@hanlincrest.co.uk>
To: "Ciemon G0TRT" <g0trt@AMSAT.Org>; <amsat-bb@AMSAT.Org>
Sent: Saturday, November 11, 2000 6:45 PM
Subject: Re: [amsat-bb] Tune the uplink or downlink?


> Hi Ciemon
>
> Answer for FM sats (data & voice) is to tune both! (The 'One True Rule'
also
> states this for Transponder sats too, although this is rarely observed in
my
> experience). You can sometimes avoid tuning the 2m uplink as the doppler's
> not as great on VHF, but it's worth being ready for it.
>
> Assuming you're using your TH-D7E in full duplex (and headphones to stop
AF
> feedback), set up a set of memory channels for each band as follows (UO-14
> example)
>
> 2m TX:
> 145.970
> 145.975
> 145.980.
>
> 70cm RX:
> 437.060
> 437.065
> 437.070
> 437.075
> 437.080
>
> That way you can leave you D7 in 25kHz European channel spacing on the
VFO,
> and use memories on each band at 5kHz spacing.
>
> At the start of a pass the RX is tuned at the high end, and you reduce the
> frequency as it passes over.
>
> On the other side of the coin, you _increase_ frequency from the lower end
> to the higher end on the TX as the sat passes over.
>
> Maplin has a large selection of Gel cells, if that's of any use. I think
> you'll find it a bit easier to reach the sat with that bit more TX power
> from you D7, especially with all the alligators about. But you can do it!
> Especially in the very early hours, or during a weekday. I found the high
> power battery pack on the D7 helped a bit in a similar (but more
expensive!)
> way.
>
> The Arrow takes a bit of getting used to, as you have to twist and turn it
> to get the right polarisation as well as the correct direction.
>
> FWIW, it took a couple of weeks for me to get a downlink after hours and
> hours of checking and double checking my configuration. It's a bit of a
> technique to learn. But then isn't that what our hobby's all about? :-)
>
> Having a headset/mic helps a bit too, so you don't have to hold another
> piece of equipment.
>
> 73 Howard G6LVB
>
> ----- Original Message -----
> From: "Ciemon G0TRT" <g0trt@AMSAT.Org>
> To: <amsat-bb@AMSAT.Org>
> Sent: Saturday, November 11, 2000 5:09 PM
> Subject: [amsat-bb] Tune the uplink or downlink?
>
>
> > After finally getting an Arrow antenna thanks to a very kind gentleman
> here
> > in the UK (I'll not give his callsign as he'd get swamped with requests)
> I'm
> > starting to have a go on the FM birds. The fabulous UK weather isn't
> > helping, but the can of worms I need to re-open is, do I tune the uplink
> or
> > downlink? I seem to remember reading that's it's just the downlink.
> >
> > I'm also after a gel cell supplier in the UK, anyone?
> > 73.....Ciemon Dunville G0TRT Sysop MB7UPG IGate
> > email - g0trt@amsat.org
> > ICQ - 6263612
> > homepage - http://go.to/APRSUK
> >
> > ----
> > Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> > To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
> >
>
> ----
> Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
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>

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