The 10 char message was transmitted beginning on the 27th and 28th. On
the 29th and today, the 30th, there was no transmission.
The safety function triggered again.
Yesterday as i remotely checked what happend, i saw just 70 mA instead
of 300 mA. So i expected there is a fault on the coil and it was
arcing.
Today i carefully inspected each of the 5 buckets and saw some small
traces of partial discharges. Added loads of Kapton foil near the
critical regions. Then i put the coil together again, but still 70 mA
on the SpecLab antenna current plot. But the analog amperemeter near
the PA showed > 320 mA! QUickly it became clear that the E field
pickup probe near the antenna has dropped down during the strong storm
last saturday! This also explains the sporadic interruptions during the
3 carrier experiment.
Now the probe is fixed again, the construction should be much more
stable. The antenna current is recalibrated. The theoretical phase
change should not be significant.
A test carrier is now running on 5170.005 Hz for an hour or so.
The 100 char message will be transmitted tomorrow 18 UTC for the 3rd
time.
73, Stefan
Am 26.10.2017 19:31, schrieb DK7FC:
OK, fine. So let's start:
f = 5170.1000 Hz
Start time: 26.October.2017 18:00:00 UTC (daily)
Symbol period: 8 s
Characters: 100
CRC bits: 16
Coding 8K21A
Duration: 11:18:24h
Antenna current: 300 mA
73, Stefan
Am 26.10.2017 17:38, schrieb Paul Nicholson:
> What abbut your new E field RX, is is ready and calibrated now?
I was expecting to bring it back in for another rebuild this week,
but, it is working quite well right now, and some parts I need
wont be here until 10th November.
So, I will leave it running until then. This weekend I will
do some calibration but that will not interfere with
reception, I will just calibrate the phase using the rising
edge of PPS received through the antenna.
--
Paul Nicholson
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