Soviet Radio Jamming: Exploring AM & FM Modulation

[bitrex]

I found the following extremely interesting article about the jamming of pro-Western broadcasts in Estonia during the Soviet period: http://www.okupatsioon.ee/english/mailbox/radio/radio.html"

One part of the author's description I'm puzzled about: "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."

I'm not sure I understand why FM was used to jam AM signals - and what the last sentence means exactly. Which transmission can the modulation not be observed on, the jamming signal or the incoming broadcast?

 

[waht]

A jammer sends a stronger signal to overpower the weaker receiving signal. To be more effective, you have to cover the entire bandwidth of the signal to be jammed. That would require many fixed frequency transmitters. But instead, one jammer can be used with varying frequency.

 

[oswaler]

I find this article on Soviet radio jamming in Estonia during the Soviet period to be quite intriguing. The use of FM modulation to jam AM signals is a unique approach that requires further investigation. The author mentions that the modulation cannot be observed on the transmission bearing wave when viewed with an oscilloscope. This could possibly mean that the jamming signal is being transmitted at a constant frequency, without any variation in amplitude, which would make it difficult to detect and track. However, more research and analysis would need to be done to fully understand this aspect of the jamming technique. Additionally, the use of a narrow strip of frequency for the jamming signal is also worth exploring, as it suggests a targeted and precise method of interference. Overall, this article raises interesting questions and provides valuable insights into the techniques used by the Soviet Union to control information during the Cold War era. Further research in this area could contribute to our understanding of the impact of radio jamming on communication and propaganda efforts during this time period.