[AMRadio] 32V-2 speech amp question

Jim Wilhite w5jo at brightok.net
Mon Jan 23 15:01:53 EST 2006

----- Original Message ----- 
From: "Brett gazdzinski" <brett.gazdzinski at verizonbusiness.com>
To: "'Discussion of AM Radio'" <amradio at mailman.qth.net>
Sent: Monday, January 23, 2006 10:53 AM
Subject: RE: [AMRadio] 32V-2 speech amp question

>I agree its pointless to run hifi at 100 watts, but making the rig
> able to run hifi, and then restricting it is a good way to go.

This seems counterproductive to me.  Why expend time and money on a 
transmitter that can pass down to 10 cycles up to 15 Kc and then restrict 
it?  Why not build one that will go down to 200 and up to 8.  Frequencies 
below 200 Cy do not contribute to the information transmitted and rob from 
frequencies that do.  With some SSB groups that like to crowd the AM 
operator, those low and high frequencies are filtered anyway.

> As far as bandwidth goes, I hear much more problems from people over
> modulating
> than from people running hifi audio. That may cause some ssb guys to
> complain
> about AM. On 40 meters last weekend, I heard 4 stations in the short time 
> I
> was listening (Sunday morning) and 3 were over modding and quite wide.
> The scope showed they were closing down the carrier quite well, and were 
> 15
> kc wide.
> I assume most AM guys on 40 have no way to monitor their modulation and
> just turn it up to what the book says, then a little more.
> Or they set it up on the scope, and when they operate, they get excited
> and talk louder or something.
> I feel if you are going to operate AM, you need to be able to
> see and hear your modulation. The ssb guys do not have problems as much as
> they have ALC built into their rigs.
> Brett

This is a particularly bad problem near where I live.  Not everyone does it, 
but a significant few do and they cause problems for all in this area.  The 
bad thing is they don't really know how to set the modulation on a scope. 
Some of them monitor their audio signal off air and think they can do it by 
ear.  It is one thing to have a wide signal and totally another to have one 
because of overmodulation.

73  Jim

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