[MRCA] SCR-274-N receiver bandwidth spec

[D. Platt]

Gentlemen,

Continuimg with my ARC-5/SCR-274-N receiver IF coil mod investigation, I 
just completed yet another coil set, this one from an ARC-5/R-26.  In 
doing so, I find yet another mechanical set-up in these coils.  This one 
has the long brass screw (up from the bottom) and threading into the 
phenolic spacer bar (vice using a nut).  All else is the same as other 
coil sets and I find that coils sets are, so far,  interchangeable.  The 
question for today is what is the original published (sic) receiver 
bandwidth of this receiver?  I'd like to know what the starting point 
should be, even though I'll be measuring unmodified and modified sets.  
At this point, I can again say that there /is/ a detectable improvement 
in selectivity.  What remains is to quantify things and, as we speak, 
I'm proceeding with the procurement of a suitable sweeper.

Another point of possible interest is the fact that in each and every 
coil set there appears a 1/2" disk "shield" positioned between the upper 
and lower coil bobbins.  Could this be what others have spoken of as a 
method of providing electrical separation (read: increased selectivity) 
between these coils?  If so, then someone back then was thinking.........

Regards    Jeep - K3HVG
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