[R-390] Using Surplus Meters in an R390A

[N4BUQ at aol.com]

I downloaded Jan's article about using surplus meters.  Looking at the 
schematic, it appears that inserting the OpAmp where the meter used to be will 
result in a minimun of 9.4K ohms where (according to what I remember posted on this 
list) the original meter's DC resistance is somewhere around 30 ohms.

Can someone comment on how/if this affects the performance in this part of 
the radio?  The text of the article indicate it is necessary to reset the 
carrier meter adjust control for the proper readings.  I assume that the difference 
of the resistance will cause this setting to be somewhat different than with a 
meter with 30 ohms resistance.

I haven't looked at the entire circuit yet and perhaps resetting the carrier 
meter adjust control to compensate the difference in resistance causes the 
circuit to become "normal" again, but not sure.

I have some replacement meters I am interested in using, but their internal 
resistance is around 600 to 800 ohms so I was looking for a way to use them.  
It appears Jan's method is easy enough, but I was wondering what the effects 
are when using it.

Any comments?

Thanks,

Barry(III) - N4BUQ