[AMRadio] AM space


Donald Chester k4kyv at hotmail.com
Wed Dec 22 10:25:41 EST 2004


There is already an AM group on approx 14.286.  I haven't run 20m AM since 
the early 70's.  It is OK for one-on-one contacts, but when roundtables 
develop, there is the problem of the erormous skip zone on 20.  You can 
count on one or more members of the roundtable being inaudible, so you spend 
much of the QSO listening to noise and random QRM.

Maybe the top end of the band would be appropriate for contacts understood 
to be 1-on-1, or at least that it is poor operating practice to break in on 
a QSO unless you are certain that you are hearing everyone satisfactorily.  
A group with 3 mutually audible members is not unusual, but once the group 
builds up to 4 or more, you can nearly always expect someone in the group 
not to be hearing someone else.

The lack of activity on 20m is an indicator that overall amateur activity is 
dwindling.  Years ago, whenever the band was open, the phone band was packed 
end to end.

Even 75m in the evening in wintertime during prime time operating hours has 
many more vacant holes than you used to be able to expect...  why not use 
these as opportunities to start up on AM outside the "window"?

We may have lost the top end of 75, 3990-4000 to Radio Deutche-Welle's 
Digital Radio Mondiale (DRM) digital broadcasting mode.  There is also one 
of these on opprox 7260.  They take up a solid swath of 10 kHz with S9 + 20 
dB white noise.  Wait till more broadcasters on 40 switch to this mode.

-k4kyv





More information about the AMRadio mailing list

This page last updated 22 Oct 2017.