[ARC5] ARC-5/SCR-274-N receiver bandwidth spec

[D. Platt]

Gentlemen,

Continuing with my ARC-5/SCR-274-N receiver IF coil mod investigation, I 
just completed yet another 80 meter 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