[Elecraft] DSP and CW?

[Fred Jensen]

>> suburban Palo Alto lot :-)  No room for a beverage, and I think I'd
>> be lynched if I tried to put up a rotatable loop!

Hi Chris,

You can make a really neat and small rx loop out of copper pipe.  I use 
one for VLF [currently listening to the 600m tests].  Mine is made out 
of `1/2" pipe, and is an octagon ... very easy to make with the 45 deg 
fittings.  It is broken at the top so it isn't a continuous piece, and 
has a T-fitting at the bottom.  I pulled a length of 8-pr in-premises 
telephone cable through it, and then tied the ends of the wires together 
to make a 16-turn loop. I use a variable cap to tune it.  For 600m, I 
needed all three sections of a tuning cap out of an ancient TRF radio, 
but for 160, a single 365pf variable works.  The noise null is really 
[really] sharp, and as long as that isn't where the station is too, the 
desired signal just pops up out of the noise for me.

Mine is about 5' across, however I'm not sure it really matters a lot 
unless it gets really small.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2007 CQP Oct 6-7
- www.cqp.org