[ARC5] Lopsided modulation

[Richard Knoppow]

     It depends on whether its FM-or PM- ing the oscillator. If 
it is its causing the asymmetrical sidebands. You should hear it 
on the oscillator signal. Try receiving it as a PM or NBFM 
signal, that is, slope detect it.
     Its not your antenna.

On 2/24/2018 4:09 PM, AKLDGUY . wrote:
> You may be onto something with the B+ kicking downward on 
> modulation. I notice that the dynamotor voltage does kick down 
> significantly. This drop may be causing the plate voltage to 
> bottom out, or even go negative!, on modulation peaks.
> 
> The MD7 modulator schematic doesn't show significant capacitance 
> decoupling the bottom of the mod tranny feed to the 1625 final 
> stage - about 1.2 uF IIRC, and I followed that when building my 
> own modulator. I suspect it may not be sufficient decoupling.
> 
> But even if the final plate voltage is bottoming out or going 
> negative, where is the literature that says this causes lopsided 
> modulation?
> 
> Neil ZL1ANM


-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL