[amsat-bb] Re: Finding yourself on the linear transponders
Patrick STODDARD (WD9EWK/VA7EWK)
amsat-bb at wd9ewk.net
Wed Jan 8 07:45:55 PST 2014
I'm one of those who has a key (paddles) to send dits. I've made
a few CW QSOs via satellite, but most of the time the paddles are
my tool to line myself up on transponders so I can work them in
SSB. I've been doing this for several years, normally with two
FT-817NDs and no computer. Lining up a CW signal through the
transponder has been a lot easier for me than talking while trying
to find myself. It also helps to compensate for Doppler when
starting out. For example, if I'm trying to get started at 145.910
MHz on VO-52's downlink early in a pass, I do not start transmitting
right on 435.240 MHz. I move my transmit frequency down a few kHz,
so I am not having to transmit across 7 to 10 kHz to line myself up.
I used to keep a note card with the TX and RX frequencies I should
use for each of the SSB satellites, so I could set my radios up
with a minimum of transmissions to get lined up. Less time used
to get lined up should mean more time to make QSOs.
As was mentioned by KB2M and W5PFG, I don't normally start a pass
at the center of the transponder. There is usually more than
enough activity in the few kHz above and below that spot, where
I might not hear my 5-watt signals coming through the transponder
there. I also know that, without using a computer, I should go off
and find a quiet spot away from the center to get lined up. I don't
interfere with others that way, and they aren't getting in my way
when I'm trying to get lined up. I look to go 10 to 15 kHz above
the center frequency to get started, then work from there. I may
move down toward the center later in the pass, if I am not working
anyone where I started out higher in the transponder. If you try to
find me this Saturday morning on those satellites while I am doing
demonstrations from a Phoenix hamfest, look for me around that area
early in the pass instead of at the center of the transponder.
W5PFG is also right about those who use too much power through the
transponders. Normally I have no problems working the transponders
with 5W signals, and sometimes will cut back to as little as 500mW
around the middle of a pass. There have been times where I am not
able to hear myself, even when the satellite is up 30 to 40 degrees
from the horizon - where I should be able to hear myself clearly
through the satellite. I can usually find a very strong signal
on the downlink when that happens, one that probably could use less
power and still be clearly heard.
On Tue, Jan 7, 2014 at 10:53 PM, Roger Kolakowski <Rogerkola at aol.com> wrote:
> Honestly...I wonder how many of the operators have keys to send those
> On 1/7/2014 7:59 PM, Ronald G. Parsons wrote:
>> Perhaps it’s just me, but it seems like an increasing number of operators
>> are trying to find their downlink by speaking into their mic while tuning
>> up and down the band, often plus or minus 20-30 kHz. Not only is this
>> disruptive to existing QSOs, it is not the most effective way to do it. My
>> receiver has a panadapter with a 40 KHz bandwidth, and I can see these SSB
>> signals swishing up and down, over and over.
>> If you don’t have computer control of your frequency, set up a switch by
>> which you can send a SHORT series of dits. Then don’t swish. Adjust your
>> transmitter is steps of about 3 kHz. Send a burst of dits at low power and
>> listen. If you don’t hear yourself, tune up or down. This way you will have
>> an effective way to find yourself and you won’t interrupt other QSOs
>> Once you find yourself, make sure you are not interfering with an
>> existing QSO. Then refine your tuning until your frequency is nearly right.
>> If you are operating CW, your done. If you are operating SSB, try holding a
>> tone generator near your mic and adjust your transmitter or receiver until
>> the tone on the downlink matches the tone generator.
>> There is probably a free tone generator available for your smart phone.
>> Better yet, try computer control of your transmitter and receiver. You
>> can easily find an Elmer on the air if you need help.
>> But, PLEASE. don’t swish!
>> Ron W5RKN
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