[AMRadio] B&W 5100B

peter A Markavage manualman at juno.com
Wed Oct 13 11:42:18 EDT 2004

With most of the current transceivers, especially Icom, reducing power
output or reducing audio, does not change this anomaly in the AM
position. Diddling with the internal ALC adjustments would reduce the
problem when operating AM. Adding external voltage to the ALC pin,
available on one of the rear ACC connectors, will override the internal
voltage and also works. Going directly into the DSP modulator, available
on one of the rear ACC connectors on some rigs also helps, and also
eliminates all the front end mike processing that contributes to
poor/fair/average AM audio.

Pete, wa2cwa

On Wed, 13 Oct 2004 07:44:23 -0400 Brett gazdzinski
<Brett.gazdzinski at mci.com> writes:
> That's because you are hitting the alc circuit on mod peaks.
> You would have to reduce your power output, reduce the audio, or 
> adjust
> the alc to a higher value.
> I notice the effect on some guys running AM on rice boxes, its 
> often
> quite noticeable on the s meter.
> That's why most run about 20 watts of carrier or less and go light 
> on the
> audio.
> My guess would be that adjusting the alc circuit to a higher value 
> will work
> good on AM, allowing the tips of the peaks to pass without invoking 
> the alc,
> but would degrade ssb service since they use the alc as a 
> compressor.
> Power output goes up, so you have to watch out, but most radios have 
> some
> extra reserve built in for long rtty or fm transmissions.
> It just always rubbed me the wrong way to spend $3000.00 for some 
> modern
> wonderbox and get a massive 20 watts out.
> Brett
> -----Original Message-----
> From: amradio-bounces at mailman.qth.net
> [mailto:amradio-bounces at mailman.qth.net] On Behalf Of Brian Carling
> Sent: Wednesday, October 13, 2004 6:34 AM
> To: Discussion of AM Radio
> Subject: Re: [AMRadio] B&W 5100B
> I have the  same downward modulation in my Icom 746 and sure 
> wish I could tune to the opposite side of the dip in final current
> to fix it, hi hi!
> On 11 Oct 2004 at 0:39, W4AWM at aol.com wrote:
> > Try tuning to the opposite side of the dip in plate current.
> > 
> > 73, 
> > 
> >  John,  W4AWM

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