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Rik,
Ok on the fade patters, yes noticed that in
the early days , 100 hz made a big change in signal , one of the
reasons for using 25 or 85 hz shift on rtty
If Gus has something like 'soundforge'
could alter the spectrum of the modulation to make up for the losses
lh/hf ,
to flatten out the pa , that may need some
feed back or something similar to reduce changes in phase , easer to
beep not speak hihi
G ..
Sent: Tuesday, May 12, 2009 8:11 AM
Subject: Re: LF: RE: SSB-Beacon
Gus, Dave, Graham,
I guess even the Q of the antenna can
attenuate the low and/or high tones.
In theory with a SSB bandwidth of 2.7kHz
and a operating frequency of 505kHz a Q = 180 would cause a 3 dB attenuation at
the ends.
But from my experience results could even be worse: Although the Q
of my antenna is only 50 I notice a significant power reduction if I tune the
antenna mid-band (502.5kHz) and QSY to one of the band edges without re-tuning.
I assume that the PA is rather "allergic" to a even rather small reactive part
of the load.
In addition the fading on 500 can indeed be very
frequency-selective. During Graham's 3 mode test I could notice different QSB
patterns between the 3 signals (that were only some 100 Hz apart).
73,
Rik ON7YD - OR7T
At 00:40 12/05/2009, you wrote:
I agree ! What
is the valve of inductor ?
Gus
- ----- Original Message -----
- From: Graham
- To: [email protected]
- Sent: Tuesday, May 12, 2009 12:33 AM
- Subject: Re: LF: RE: SSB-Beacon
- Gus/Dave
- Might be the Q and BW of the rf path causing a little
rounding of the audio spectrum , need to boost the lf and hf ..or
attenuate the mid range ?
- G .
- From: Dave G3WCB
- Sent: Monday, May 11, 2009 11:08 PM
- To: [email protected]
- Subject: LF: RE: SSB-Beacon
- Gus,
- Your SSB is about readability 4, signal
strength 5 in QSB, with lots of static crashes. It sounds like you might
need a bit of audio processing/compression to boost your "talk
power".
- My RX is an ICOM IC-PCR1000 with a tuned
pre-amp, and my antenna is my usual 500/137kHz "tee", 20m long and 5 metres
high.
- I have saved a couple of *.wav files - do you
want me to send them to you?
- 73, Dave G3WCB IO91RM, nr Windsor, S.E.
England
- -----Original Message-----
- From: [email protected] [
mailto:[email protected]]On Behalf Of Gus
- Sent: 11 May 2009 22:18
- To: [email protected]
- Subject: LF: SSB-Beacon
- Dear LF group,
- I test a SSB beacon this evening on 505,5 kHz USB.
- Power is abt 1W ERP and there is also a CW id include....
- Reports are wellcome.
- 73 de Gus SM6BHZ
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