[aprssig] HF-to-UHF link? SUCCESS!

[Bob Bruninga]

Sending this to APRS sig, since most of you have at least one end of a SKYCOMMAND and dont use it...  Neither did I till this weekend.  Took me 2 hours of fumbling to get it working, but now I love it!  Here is the post-action report:

The Scout event using SKYCOMMMAND was perfect!

I sat my TS2000 about 1000 feet away from the JOTA station and operated it remotely with my D7 HT switching between VFO A/B on 14.230 SSTV and 14.070 PSK-31.  The audio out of the D7 then fed into the LINE-IN of four laptops on 2 tables for the scouts to watch either SSTV or PSK-31.

We never once heard any co-band interference even though I was listeing on 14.070 amd 14.230 and the other JOTA station was making SSB contacts also on 20 meters!  We were only 30 feet apart (beacuse my HF receiver was acutally 1000' away).

The remote TS2000 ran all day on some solar panels and a fishing-pole 16' vertical.  It was unattended out by the main gate.  Sun never came out, but the 15 amp nominal solar panels did provide about 5 amps in the heavily overcast day.

BENEFIT!  A side benefit was that ANYONE anywhere at the Jamboree, could tune in the SKYCOMMND link on 147.57 and hear the HF audio, and if they had a laptop, they could see all the same SSTV and PSK31 that we could.  This is a fantastic way for the scouts to really get some hands-on experiece back in thir camps on their own time.  As it was, there were 12 sessions all day, with each session at the ham area broken up into 3 sub-groups so that each kid only got about 10 minutes or less at the PSK/SSTV station.

But with the 2m audio link of the Skycommand, the other dads that had 2m HT's could go back to their various camps and demo PSK-31 and SSTV on their own time.

NEXT TIME, I am going to have two separate links.  One each on PSK31 and SSTV so that I dont have to switch back and forth.  Fortunealy at work we have two TS2000's, but if I didnt, I'd just nail up a pair of old 2m HT's to some cheap HF receivers and accomplish the same thing.  No need for the fancy SKY commmand, since I was always within 1000' and could exercise appropriate transmitter control manually.

GROUP SKYCOMMAND!  There was another special benefit.  ANYONE at camp that also had a D7 or D700 could also operate SKYCOMMAND at the same time.  ANyone can set their D700 and D7 to the SAME generic callsigns as our skycommand and then their radio will display the same REMOTE HF front panel as ours.  So in effect, anyone in camp can SEE what HF freq the remote HF is on, and could even control it.

See the details on http://aprs.org/skycommand.html

SCOUIT DEMOS:  This same technique can be used for regular meeting-night scout demos even in windowless meeting rooms in basements.  Just set up the HF rig in the parking lot and using a low-power RF link, transmit it in doors to any laptop to display SSTV or PSK.  No remote control needed since these two modes use FIXED HF channels and so no remote tuninig is needed.

RESTARTING;  One thing I learned was what to do when the D7 battery ran down and dropped the command link. I'd swap in another battery, and then try to re-enter skycommand mode.  It never worked the first time.  ("Press[0] to activate link").  But I found that if I exected SKYCOMMAND and then re-entered COMMANDER mode, that it would then pick up the link and continue.

Bob, WB4APR