Re: Satellite Modes

Peter Laws / N5UWY

On Thu, Mar 11, 2021 at 12:54 AM <> wrote:

Newer satellite mode-names do use a combination of two letters, representing the up- and down-link band.
As there are: H 15m, T 10m, V 2m, U 70cm, L 23cm, S 13cm, C 6cm, X 3cm, K 1,2cm, Q 6mm
Something got stuck in my head a while back and I made a list:

S band is a problem because, by IEEE's naming, amateurs have two bands
- 13 and 9 cm.

My research shows that 6 mm was designated "R" (not Q) by AMSAT-DL in
the run-up to the ill-fated OSCAR 40 while IEEE calls it V ... but of
course AMSAT used V for 2 m. It's all good.

I do have the citation for AMSAT's band designators on the page above
but if I have a copy of the document ... I've misplaced it! The title
is listed, though.

The reason for this was because the original modes, A (2 up, 10 down),
B (70 up, 2 down), J (2 up, 70 down) clearly wouldn't scale with the
number of bands that OSCAR 40 (Phase 3D prior to launch) was to have
and follow on spacecraft were expected to have. So, wisely, they
went with a letter for each band and, as Suitbert notes, the first
letter is the uplink, the second is the downlink.

Sadly, as is often the case, old timers couldn't let go and insisted
on using the old single-letter modes leading to mixed messages in
AMSAT publications.

I would suggest mapping the uplink and downlink bands entered by the
operator to those bands' appropriate letter but allow the operator to
override the default should they wish to use the obsolete designator.

Peter Laws | N5UWY | plaws plaws net | Travel by Train!

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