Hello Alex,
Thank you for trying! I guess we will have much better results in
November or December this year. But we keep on trying. The days become
longer and longer, maybe we can make it during daytime soon. There are
many things to try out :-)
I discovered a dead FET !! on my linaer PA. It died by heat, not by
over-voltage. Dying by heat can go slowly for a FET. Also i have that
safety function, SpecLab stops to drive the PA when the antenna current
drops below a certain limit. If this happens, the FET is almost dead
but not completely dead. It cools down before it is completely dead and
so it can be used again after some time but of course it is not working
as expected any more. It looks like this is what happened here. I drove
the PA quite on the limit, about 275 W DC input power. There will be a
better PA version soon, with 2x 3 FETs in TO-247 case, each side on a
separate heat sink! So i don't need to isolate the FETs from the heat
sink and will get an even lower case temperature...
Running a stable 700 mA on 8270 Hz again is the goal for the next days,
then we can continue testing on VLF!!! :-)
73, Stefan
Am 27.04.2017 19:36, schrieb Alex K:
Hello
VLF, Stefan,
unfortunately no decode here of both transmission of 22 and 23 Apr.
Files for reprocessing are here: http://rn3aus.narod.ru/ebnaut-22-23apr2017-6470.zip
Thus I conclude that I have only a screenshot with traces of plain
carrier 6470.005 sended days before ebnaut transmission.
My grabber is now stopped for some reasons and will run again at
weekend.
73 de Alex/rn3aus
Воскресенье, 23 апреля 2017, 1:42 +03:00 от DK7FC
<[email protected]>:
Hi VLF,
another chance, the same msssage two hours earlier, improved timing
towards the east...
f = 6470.100000 Hz
Start time: 23.Apr.2017 05:00:00 UTC
Symbol period: 40 s
Characters: 2
CRC bits: 32
Coding 16K21A
Duration: 11h, 22m, 40s
Antenna current: 460 mA
73, Stefan
|
|
