Generator meshajushtshego deitsvija
Jag har grävt vidare i arkiven och funnit schemat till de effektiva störgeneratorna som användes från slutet av 50-talet och säkert många år därefter. Fyra rör typ 6N7 behövs. Även en funktionsbeskrivning ingår. Bara att sätta igång att bygga.
Det är Igor Hallas som jobbade som operatör på Estonian SSR Radio Center som skrivit om sina minnen. Intressant läsning må jag säga.
"The noise with which we jammed the incoming broadcasts was produced by a special generator. This was known as the GMD – generator meshajushtshego deitsvija, in direct translation, the interference activity generator. Each objekt had a GMD, and each radio bureau had one as a back-up. After every minute of producing interference noise, each generator would also transmit its call sign. For instance, objekt 65’s call sign was the Morse code letter for Y, objekt 602’s, the Morse letter for V.
A GMD unit actually consists of four separate generators, each one with a twin triode 6N7 (see diagram).
G1 gives the frequency 135Hz
G2 gives the frequency 320Hz
G3 gives the frequency 3Hz
G4 gives the frequency 5Hz
All of them are multivibrators, therefore, impulse current generators.
G1 and G3 are the basic generators, while G2 and G4 are the sub-generators, which modulate the frequency of the basic generators. G2 modulates G1’s frequency by +-3Hz, and G4 modulates G3’s frequency by +-5Hz. The noise produced by G1 and G3 are blended together to create the constant static and blaring with which the radio broadcasts were jammed, and which the radio listener finally heard. These Russian noise generators were actually quite cleverly made. Although all LW, MW, and SW broadcasts were always amplitude modulated (AM), amplitude modulation was not used for jamming, but rather frequency modulation (FM). And this, on such a narrow strip as is needed in a band for 1 station, that is, 9-10kHz. If the transmission bearing wave is viewed with an oscillograph, the modulation cannot even be observed, as if it didn’t exist.
The noise generator was regarded as the most secret device at the objekt. Outwardly, it didn’t differ in any way from a common amplifier. On photo nr. 3, a generator (on the bottom) can be seen on a stand together with common amplifiers.
The noise generator, or jammer, was the last device to be explained to a new employee at an objekt. Any other Estonian Radio Center employee who came there and happened to ask questions about the device, was told that it was just one of the many amplifiers in the broadcasting station.
As a matter of fact, I had an experience like that when I was still going to Technical School and was doing my internship at Laitse radio broadcasting station. For some reason, they had a GMD there at the time. I stumbled upon it, and not knowing what it was, of course made inquiries. The response was, that this was a modulation amplifier. "
Mer här:
Igor Hallas 1
/Bengt
