[AMRadio] Ranger Modulation


Larry Taft ltaft at charter.net
Wed Nov 15 23:28:21 EST 2006


Try reversing the phase of the audio by swapping the output leads of the 
modulation xfmr.
Asymmetrical modulation?  And too much in the negative direction is the 
flat line.
Weak tube in the audio chain causing lack of gain needed for the 
positive peak.
I understand what I'm trying to say.  I reserve my right to say it wrong!

Larry  K2LT

Jack Schmidling wrote:
> I suspect my mic problem is with the cartridge and I will be getting a 
> new one.
>
> The now problem seems to be that I just can not seem to get 100% 
> modulation no matter what mic I use.
>
> When I adjust the scope so the carrier is +/- 1 div, I can never get 
> it quite to +/- 2 and 1.5 is pretty typical.
>
> On the other hand, I have no trouble getting a flat line between 
> cycles with too much audio which I understand is the indication for 
> over modulation.
>
> I am using a audio generator at 1 kHz talking to an earphone, against 
> the mic.  The modulation meter can easily be pinned if I use an 
> amplified mic but it has no effect on the top of the envelop.
>
> What does all this mean?
>
> js
>




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