Topics

Hailing channel and intermodulation suppression

Tom Hayward <esarfl@...>
 

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

PE1RDW <pe1rdw@...>
 

On Sat, 22 Jun 2013 05:34:06 +0200, Tom Hayward <esarfl@...> wrote:

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
you can always opt for 2 antennas, from what i understand the UDR is not full duplex anyway so desensing should not be a problem.

--
73 Andre PE1RDW