[amsat-bb] WSJT-X FT8 QSO confirmed between W2JAZ and W5RKN on FO-29

Matthew Stevens matthew at mrstevens.net
Tue Oct 17 19:36:59 UTC 2017

Experimentation isn’t the problem, too much power is. It’s bad enough on SSB, worse with CW, and killer on constant duty cycle modes like FT8.

I’m one of the few newer sat guys I think that actually likes CW on sats....BUT, I know that more than a couple watts of CW into my Arrow can kill the transponder for everyone else. With digi, the effect is far worse.

It’s already bad enough when I can tell that certain SSB stations have come on somewhere else in the passband, because my signal, which moments before was very loud using 500mW of uplink power, completely disappears even though I bump up the power to 5 or 10w.

I personally don’t see the point of a mode like MSK144 on sats, which is designed for extremely weak signal contacts like meteor scatter. But, if somebody wants to experiment that’s cool. Just keep the power down - WAY down, and I don’t think anyone would say a word about it. But no matter the mode, If one station is shutting out all others in the passband, well, you’re probably going to see some ranting lol.


- Matthew nj4y

Sent from my iPhone

> On Oct 17, 2017, at 15:17, Zach Metzinger <zmetzing at pobox.com> wrote:
>> On 10/17/17 12:28, Ronald G. Parsons wrote:
>> First of all, let me apologize for any disruption I may have caused
>> by my tests (experiment, interference, ...).
> To all,
> Isn't our mission one of experimentation? What, exactly, is wrong with
> utilizing, with the proper power and bandwidth limitations, part of a
> transponder passband for non-SSB/CW modulation?
> Yes, there are considerations regarding AO-7, but that is a problem we
> face using any mode on that satellite. CW signals routinely modulate the
> SSB voice signals, unless operators take care to restrict uplink ERP to
> the minimum necessary for a QSO.
> Modes like Olivia, which has FEC and can track frequency changes
> (Doppler or otherwise), should be easily workable over satellite, and
> may not need to be much above the noise floor.
> Ron may have been running a bit too much uplink ERP, but I don't think
> he needs to be beaten over the head for doing what Amateur Radio is all
> about: experimentation.
> --- Zach
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