Re: LF: RE: SSB-Beacon

[Rik Strobbe <rik.strobbe@fys.kuleuven.be>]

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: rsgb_lf_group@blacksheep.org

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: rsgb_lf_group@blacksheep.org

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: owner-rsgb_lf_group@blacksheep.org [ mailto:owner-rsgb_lf_group@blacksheep.org]On Behalf Of Gus

Sent: 11 May 2009 22:18

To: rsgb_lf_group@blacksheep.org

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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