I'm sorry, i forgot the USB-RS232 converter so it wasn't possible to
transmit in OP4 with the netbook. I tried to find an alternative
solution by keying the PA with the 1700 Hz tone generated by Opera. I
used some of the electronic stuff which i carry arround in my car since
the VLF times, an audio 1:4 transformer with headphone plugs, a 1 uF C
and some crocodile clamps. It was possible to key the PA with this
construction. However the tone frequency is fixed and 1700 Hz is quite
low, lower than the frequency need to overcome the RC time constant of
the key input of my PA. So there were heavy sidebands and the antenna
current was low and probably this signal was not useful to get a decode.
Next time i will have all i need.
And next time i know what to optimise to get a stronger signal. And next
time is a step closer to the winther!
73, Stefan/DK7FC
Am 29.07.2012 21:30, schrieb Graham:
No OP decodes yet ?..stations are monitoring 477
just switched to 477 now 20-00 bst (also 500 with ft897+short ae)
G..
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From: "Stefan Schäfer" <[email protected]>
Sent: Sunday, July 29, 2012 2:12 PM
To: <[email protected]>
Subject: LF: MF: 630m band dipole tests today
MF,
I will now start to do my tests with the MF dipole. It may take 2
hours until i am QRV.
I have a CW key and a PC to allow Opera4 transmissions. For CW i want
to transmit on 472.5 kHz, so if you want to try, just see if you can
catch me.
73, Stefan/DK7FC
Am 25.07.2012 23:20, schrieb Stefan Schäfer:
Another pretest.
The dipole is ready now (still at home). I measured the DC
resistance between the ends: 27 Ohm. One reason why i won't get 100%
efficiency :-)
The length is now 309m. I hope this will reduce in a resonance
arround 475 kHz...
73, Stefan/DK7FC
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