[amsat-bb] Mount Carmel HS ARC marine buoy deployed and transmitting

[Phil Karn]

On 7/17/20 6:47 AM, Chris Thompson wrote:
> Very cool, thanks for posting the details.  Sounds like a great
> project.  Is it relaying any telemetry such as water temperature?  Or
> just position, which is interesting for sure.

It's sending temperature and battery voltage, though the encoding is
coarse. Reported temp is 20C, but it's in 5C steps and maxes at 25C; the
tracker was designed for balloons after all. Reported battery voltage is
4.6 (nominal 4.5); I don't recall the resolution but it's probably 0.1V.

I still haven't heard it myself, though I haven't been listening
continuously. All the WSPR signals I'm getting on 20 m are > 1000 km
away, so I'm probably in the skip zone. Or my G5RV is just too crappy an
antenna.

>
> Managing to upload data to a sat would be a fantastic next step, but I
> can already see the technical challenges with that.  Perhaps relaying
> the data via an open linear transponder using PSK, with a sensitive
> ground station listening for the results?  That seems more realistic
> than uploading data to a mailbox like FalconSat-3 or similar.
Yeah, satellite relaying would be cool. I know Bob, WB4APR, has had that
as his obsession for many years. I don't see why uploading to a mailbox
should be too difficult, considering we're in the middle of the ocean
without a lot of competition. We have all sorts of other ideas, like
data collection, an adaptive HF data link to dump it to shore, etc. But
we have to beware the dreaded "second system" effect.
>
> Anyway, great to see projects like this engaging students.

That's the idea! But a lot of things have conspired to interfere with
that process this year, sigh.

Phil