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AW: Hailing channel and intermodulation suppression

"siegfried jackstien" <siegfried.jackstien@...>
 

Repeater builders use a highpass lowpass combination (procom 70/6 or
similar) to transmit and receive on the same antenna ... now my rough guess
is that you could add such a filter to your antenna input and can transmit
on one frequency without desensing on the other frequency

Dg9bfc

Sigi

-----Urspr√ľngliche Nachricht-----
Von: UniversalDigitalRadio@...
[mailto:UniversalDigitalRadio@...] Im Auftrag von Tom Hayward
Gesendet: Samstag, 22. Juni 2013 03:34
An: UniversalDigitalRadio@...
Betreff: [UniversalDigitalRadio] Hailing channel and intermodulation
suppression



I'm trying to embrace the concept of A Hailing Channel for Packet
Radio, but I've run into an engineering roadblock. I am assuming the
"hailing channel" will be something like 440.800 MHz APRS, and the 56k
data transfer channel will be 430.9 MHz. These are 10 MHz apart. How
can I support this on a crowded site that requires a [normally low
bandwidth] intermodulation suppression panel (isolator / low pass
filter)?

With the independent TX/RX connector option, is the internal TX/RX
relay preserved? I'd hate to try to implement an external TX/RX relay
with <10ms turnaround time.

Tom KD7LXL