We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations. Always consult with the appropriate authorities if you have questions concerning what is permissible in your locale.

Author Topic: 7405 jammer stomping on Bulgaria 7400  (Read 2134 times)

Offline Zoidberg

  • DX Legend
  • ******
  • Posts: 2364
  • Gopher Stomp, Texas
  • i c u
    • View Profile
    • Email
7405 jammer stomping on Bulgaria 7400
« on: July 22, 2010, 0439 UTC »
7/22/10
0430z: Jammer on 7405, presumably Cuba over Marti, also QRMing Radio Bulgaria on 7400.  Bulgaria audible only on LSB, wiped out on USB and wideband AM by 7405 jammer.

Been awhile since I noted any jamming between Marti and RHC, last time was on 49m band a couple of years ago.  At that time it seemed the jamming was confined to one sideband to avoid QRMing adjacent freqs.
That li'l ol' DXer from Texas
Unpleasant Frequencies Crew
Al: Palstar R30C & various antennae
Snoopy: Sony ICF-2010
Roger: Magnavox D2935
(Off-air recordings.)

Offline SW-J

  • Hero Member
  • *****
  • Posts: 544
  • Dallas, Texas
    • View Profile
Jammer 2nd/3rd harmonic? Re: 7405 jammer stomping on Bulgaria 7400
« Reply #1 on: July 22, 2010, 1600 UTC »
7/22/10
0430z: Jammer on 7405, presumably Cuba over Marti, also QRMing Radio Bulgaria on 7400.  Bulgaria audible only on LSB, wiped out on USB and wideband AM by 7405 jammer.

Been awhile since I noted any jamming between Marti and RHC, last time was on 49m band a couple of years ago.  At that time it seemed the jamming was confined to one sideband to avoid QRMing adjacent freqs.

Get an opportunity, check the 2nd and 3rd harmonic of the Cuban jammer; I've copied their jammer's third harmonic up in the CB 'outbander' spectrum before (while observing for DX) ... it came and went briefly as the propagation at 27/28 MHz to the area of the island opened up briefly ...

It would seem the jammer's harmonics were not so tightly controlled (takes BIG parts to perform as a high-power low pass harmonic filter and they may have just not installed one or simply bypassed it after it failed ... and *I* would not want like to be the one to let Fidel know that his 'jamming' department was not 'on-the-air' b/c of a simple filter failure, after all, they're jamming, and that's not entirely in accord with WARC rules and regs either ...)

 
o Icom IC-756ProII, ProIII, Alinco DX-70, Kenwood TS-680s
o WinRadio G303e, Degen/Kaito 1103/DE1103, Stoddart NM-25
o 1/2 wave 80m Dipole used with several tuners
o Tuned loops from 2' thru 16' diam. capable of 160m thru 10m

Offline Zoidberg

  • DX Legend
  • ******
  • Posts: 2364
  • Gopher Stomp, Texas
  • i c u
    • View Profile
    • Email
Re: 7405 jammer stomping on Bulgaria 7400
« Reply #2 on: August 03, 2010, 0500 UTC »
Bubble jammer on 7405 over Radio Marti slightly less effective tonight.  Actually able to copy some of Marti between 0400-0430z, including their distinctive interval jingle at 0430z mark.

Interesting flip-flops in signal strength between the jammer and Marti.  Considering the path here to Texas from Miami and Cuba aren't much different on paper, I could hear distinct selective fades between both between 0400-0430z.  Good ol' no-sunspot propagation - never know what you'll get.
That li'l ol' DXer from Texas
Unpleasant Frequencies Crew
Al: Palstar R30C & various antennae
Snoopy: Sony ICF-2010
Roger: Magnavox D2935
(Off-air recordings.)