Topband: CY9C

[Rudy Bakalov]

Is this published/documented anywhere? My in-band tower is about 150’ from the main tower and there is significant interference (but manageable ) between the two radios.

Rudy N2WQ

Sent using a tiny keyboard.  Please excuse brevity, typos, or inappropriate autocorrect.


> On Sep 7, 2024, at 3:55 PM, Jim Brown <jim at audiosystemsgroup.com> wrote:
> 
> On 9/7/2024 11:17 AM, Rudy Bakalov wrote:
>> How does this work? IF this is indeed the case, this would be a great solution for multi-op contest stations.
> 
> Very careful design of both RX and TX antennas and their matching networks, physical separation of RX and TX antennas, combined with very careful design of very narrow-band pass and reject filters for RX, and combiner networks for TX that prevent each TX from seeing the other. Combining networks for TV and FM broadcast transmitters have been in common use in major cities for more than half a century at sites like the Empire State Building, the World Trade Center, Chicago's Hancock Building and Sears Tower, and mountaintop sites in the West.
> 
> Very complex design of both the system and individual components. As one of my old EE profs would say, "non-trivial!"  Uses everything I learned in EE 60+ years, and at a much higher level than I ever did anything. :)
> 
> 73, Jim K9YC
> 
> 
> 
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