Hi Paul,
For the dog, one sausage is enough. But you need to put it on a charged
HV capacitor with a case at GND. I have such capacitors, 5 kV / 10 uF.
About 0.15 m diameter and 0.2 m high, with a single central ceramic
feedthrough. It contains 125 Joule when charged. I have 18 of them :-)
Just put the sausage on the top, charge it up and place it on the ground
:-) Wuff!
For the power supply, maybe a cheap tric helps to start the supply
securely, see attachment. Just press the button for a second in case the
supply doesn't start up. The C depends on the C of the C on the far end
73, Stefan
Am 19.12.2017 21:32, schrieb Paul Nicholson:
Stefan wrote:
> f = 17470.1000 Hz
> Start time: 18.Dec.2017 21:30:00 UTC
> Symbol period: 45 s
> Characters: 2
> CRC bits: 14
> Coding 16K21A
Eb/N0 -4.9 dB with that one.
Perhaps two more repeats necessary.
> So i'm trying a new message with just 2 characters before
> going down to 5170 Hz.
I look forward to that, it is the best way to test the new
H rx, to see if the strange noise floor seen in the old rx
has gone.
PS
Having some last minute problems with the new rx: the PSU
does not start reliably when fed via a long cable. Had
this problem with the E rx and it appeared to be the
reservoir caps too high. Now I discover the cause is
the resistance of the cable. Just ordered 48V to 12V DC/DC
converters and a 48V power supply, hopefully that will be
less sensitive to the cable resistance. Next day delivery
but it wont arrive in time to use it tomorrow. I'll have
to improvise something out of the junk box!
PPS
A test run today - managed to avoid The Grendel with a
carefully timed sausage and got through the farm yard
without being bitten! Not thinking ahead, I'd only
taken one sausage with me. You can guess what happened
on the return trip.
--
Paul Nicholson
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