BC-DX 789 05 Jan 2007 Private Verwendung der Meldun

6109.76, CVI Santiago, in Portuguese 0715 UT March 29. (wb)
Tuning above 12 MHz at 0115 on April 2, I came upon a broadcast signal on
12195, where there isn't supposed to be anything. Sounds like thinly
disguised religious pop. Oh oh, another spur from CVC? Then immediately
checked 12275, where Brian Alexander has reported a CVC mixing product.
There that is, amazingly strong, could easily be mistaken for a
fundamental, and stronger than 12195.
We see that CVC is operating not two but three transmitters on the 11 MHz
band between 0100 and 0400 UT:
11665 Spanish at 0100-0800
11745 Portuguese at 0000-0400
11970 Spanish at 0100-0400
I then went looking for all the other possible mixing products, and found
most of them in the next few minutes! What a dirty installation they have.
Summarizing:
12275 11665 over 11970 at 305 kHz, strong
12195 11745 over 11970 at 225 kHz, less strong, mostly Port audio
12115 doesn't fit pattern but weaker // 12195, 80 kHz from it.
Both of these had CODAR QRM, BTW
11825 11665 over 11745 at 80 kHz [unheard but probably obscured by
splash from big signals on 11815 and 11835.]
11585 11745 over 11665 at 80 kHz, weakest.
11520 11970 over 11745 at 225 kHz, weaker than 12195, Sp + Port.
11360 11970 over 11665 at 305 kHz, strong.
This was another DXpedition to a park in Enid away from household noise
sources, this one Government Springs Park. 0058-0138 UT April 2.
(Glenn Hauser, GSPDX, OK-USA, dxld Apr 4)
And taking another look at the CVC sked, we see that there is another jam-
up of three transmitters on one band, 49m:
5960 Spanish at 0800-1200
6070 Spanish at 2300-1300
6110 Portuguese at 0400-1100 [axually 6109.77v, so mixes would be off too
making hets if anything is next to them]
So here are those hypothetical mixing frequencies, and times they would be
on; being closer together and not so far out of band, they will be harder
to spot, and more likely to blocked by legit signals:
5810v 6110v over 5960 P/S at 0800-1100, 150 kHz
5850 6070 over 5960 S/S at 0800-1200, 110 kHz
6030v 6110v over 6070 P/S at 0400-1100, 40 kHz
6150v 6070 over 6110v S/P at 0400-1100, 40 kHz
6180 5960 over 6070 S/S at 0800-1200, 110 kHz
6260v 5960 over 6110v S/P at 0800-1100, 150 kHz
6030v would normally be totally buried by R. Marti and Cuban jamming but
during the dentro/fuera-Cuban truce UT Mondays, could well be enough to
block the new Radio ICDI, Central African Republic, should it actually be
on and propagating from *0500. Note that 5810v could also be confused with
the Colombian 6010v/5910v leapfrog which we know exists not to mention
CVC fundamental 6110v confusing with the other Colombian mix on 6110v.
WEWN is currently switching from 5810 to 5850 at 0500 UT. Other possible
mixes of CVC could be worked out, but they would have to be between
transmitters on different bands, so probably less likely tho not
impossible.