[Lowfer] New to the list. A few questions re: Lowfers and longwave

[Lyle Koehler]

Regarding my homebrew synthesized LowFER receiver -- yes, it works fine, but
I wouldn't recommend it as a construction project for anyone else. The
circuit is just too complicated and very messy to troubleshoot. At the time
it was built, my primary receiver was an Icom IC-751A. That was a great rig
for copying LowFER CW signals, but it was very difficult to use for the
narrowband stuff that requires extremely good receiver accuracy and
stability. My solution was a receiver dedicated to LowFER CW and BPSK
reception. It covers only 160-190 kHz, and isn't even very good on the lower
portion of that range. (At the time, military GWEN signals wiped out
everything below 175 kHz). Like most projects, by the time I finished
building the receiver, I had thought of better ways to do everything in the
circuit. Anyway, after I acquired an IC-706 (which is horribly insensitive
on LF but works fine with an external preamp), the homebrew receiver has
spent most of its time languishing on the shelf. Now the IC-756PRO has
replaced the 706 as my primary LowFER receiver, mainly because it has a wide
range of choices for IF filter bandwidth.

The consensus among LowFERs is that the Icom R75 is a very good choice as a
receiver for LF, BCB DXing, and general shortwave listening.

Commercial LF preamps may be available from companies like LF Engineering,
Palomar and Datong. Someone else may be able to offer advice on which unit
would be best -- I haven't ever used a commercial preamp because they are so
easy and cheap to build. As Gary, WA6DTX points out, a major concern is
overload by strong local broadcast stations. I would expect KSTP to be even
more of a problem than WCCO in the Arden Hills area. An essential feature of
a preamp will be a good low-pass filter in the front end.

My web site has a few "solderless" construction projects at
http://www.cpinternet.com/~lyle/proto/LFproto.htm  That might be a way to
get started for anyone who is unsure about soldering skills, or who is
unfamiliar with reading schematics. A LowFER transmitter and an LF-to-HF
receiving converter are included in the projects.

Lyle, K0LR