Tim Shoppa wrote:
On May 5, 12:13 pm, "D.K." wrote:

Hi all,
I'm considering to upgrade my receiver ICOM R75 with narrow CW filters. My
main interest is NDB listening in the LW band.
There are 2 possiblities:
a) ICOM FL101 (CW narrow 9mHz IF, 250Hz) + ICOM FL53A (CW narrow 455kHz,
250Hz)
b) INRAD 121 (CW narrow 9010.6kHz, 250Hz) + INRAD 122 (CW narrow 455kHz,
250Hz)
Which combination is the better one in terms of quality and efficiency.
Price does'nt matter.
Any advice is welcome!
Thanks in advance


You mention NDB's... note that NDB's are not the usual CW (carrier
interrupted), but are instead AM stations broadcasting the tones of
400 or 1020 Hz. To receive these in AM mode, you'd need bandwidths of
800 Hz and 2040 Hz respectively.

If you're really interested in NDB's and "true" LW activity, a PC
sound card and a waterfall-type graphical program will set you
furthest ahead.

N3QE

You're correct about all US domestic NDBs.

There still are NDBs elsewhere that transmit a unmodulated carrier most
of the time and then switch to on/off keyed morse ident periodically.

Such systems require a BFO to hear the morse ident.

Even 'modern' airborne ADFs still have a BFO mode... some things never die.

Bob