[Elecraft] OT: 160/80 M Rx loops

[Ken Kopp]

I've had enough off-reflector questions about my loop that an 
on-reflector reply is probably warranted.

I've had mine in use for 25+ years and early-on had it mounted 
on a small TV rotator.  The directional characteristics of a loop
are such that there's little/no reason to rotate it -UNLESS- you
want to take advantage of the very deep and narrow null off each
side of the loop to null noise ... or the mega-KW ERP contest
station ... in the next county. (;-).  

My loop is made from 1/2" "hardline" with a 1/8" break in the
shield at opposite the feed point. Either 50 or 72 ohm coax is
OK ... there's no difference in this application. The circumference 
of a loop should not exceed .06 wavelength, BTW.  There is a 
two-transistor preamp at the feedpoint of mine that's powered 
w/12VDC via the coax running to the loop.  The feedline is about 
500' of 72 ohm (RG-59) coax. 

A Google search of "160M receive loops" or "BCB receive loops"
will produce lots of information.

Some "serious" loop users ground their TX antenna ... especially 
verticals ... while receiving because of the re-radiation of noise from
the vertical into the loop.

73!  Ken Kopp - K0PP
ElecraftCovers at rfwave.net