[AMRadio] Modulation Question

[Bob Bruhns]

Hi again, Ed.

Oops, - this isn't the website I was thinking about.. heh heh.   Oh yes...
it's a mailing list!  I remember... I remember...

Check Dino's article on DX-100 screen modulation at
http://www.amwindow.org/tech/htm/scrnmod.htm

You can also check my articles on peak-limiting compressors at
http://www.amfone.net/AMPX/61.htm  and
http://www.amfone.net/AMPX/issue_number_79.htm

  Bacon, WA3WDR


----- Original Message ----- 
From: "Edward B Richards" <zuu6k at juno.com>
To: <amradio at mailman.qth.net>
Sent: Wednesday, April 14, 2004 8:03 PM
Subject: [AMRadio] Modulation Question


> Hi Guys;
>
> I am new to this list so please forgive me if my questions are dumb or
> redundant. I just rebuilt a much abused Heathkit DX-100B. As far as I can
> tell it is operating OK into a dummy load. I have not put it on the air
> yet. For one thing, I don't have a 75 meter antenna up yet. I have a
> mobile ant I will install as soon as I have time. I do have a MFJ G5RV jr
> that is good for 40 meters and higher. I have not heard any AM on
> anything but 75 meters. Is there activity on 40 and / or 20 meters?
>
> I modified a scope to serve as a modulation monitor. I noticed 2 things
> that puzzle me.
>
> 1. It is hard to tell modulation percent with voice as the waveform keeps
> changing  and unless I use a sine wave I can't sync it to get a good
> envelope pattern. Any trick to this?
>
> 2. Using the mod mon I see that it is very easy to over-modulate. If I
> keep the modulation down so I don't see short bright lines in the center
> of the screen (carrier disappearing, I think) , the average modulation is
> around 50% except for occasional peaks. Is this normal? would a
> compression amplifier help? Thank you.
>
> 73, Ed Richards K6UUZ
>
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