[App_rpt-users] Quad Radio PCI Card & Icom IC-F221s

[John (WB5NFC)]

Is anyone else using a Quad Radio PCI Card with a pair of Icom IC-F221s 
configured as a repeater? 


I've worked my way through the need for a COS pull-up resistor, but I can't seem 
to get the audio right. After setting proper deviation, I hear what sounds like 
a lot of computer-generated hash on the transmitter and a 'ghost' signal from a 
local commercial broadcast station in the background.  I suspect that one of my 
problems is not using shielded cable from the Quad Card to the ICOMs. I could 
not find the appropriate shielded cable locally, so I had hoped to get by by 
sacrificing an old twisted-pair jumper. I crimped on a new RJ-45 with the 
following pin-outs: 


ICOM Receiver Discriminator Audio (330 mVRMS @ 100 k ohms --> Pin 1Quad Radio 
RJ-45 

ICOM Tramsmitter (Radio Modulation IN) (330mV RMS) --> Pin 7 Quad Radio RJ-45 
ICOM PTT -->  Pin 5 Quad Radio RJ-45 

ICOM COS  (when radio is properly programmed and a pull-up resistor is used) --> 
Pin 2 Quad Radio RJ-45 

ICOM Ground --> Pin 8 RJ-45 

RX de-emphasis jumper is enabled and the best results seem to be obtained with 
TX pre-emphasis enabled (even though it is not recommended). 


I will be ordering shielded cable for RJ-45s Monday, but is there anything else 
I have missed?

Thanks for any suggestions.

John / WB5NFC



      
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