[Premium-Rx] WJ-8718-9 Preselector.

[David Schofield]

Hi All,

I've just dropped on the digital preselector option for my 8718-9, but can't for the life of me figure out how it's supposed to connect to the receiver.
The preselector filter unit is self explanitory, it sits between the antenna socket and the input converter, with a short SMC patch cable connecting it's output back to the converter.
The filter assembly then has a 9 way D-type lead connected to it that mates with the output of the preselector decoder PCB, that apparently sits in the PRE-XA2 slot in the control cage.
My problem is, that try as I might, I can not locate the PRE-XA2 slot....
All the unused slots in my receiver seem to have nothing but power and ground connections, looking at the schematic diagram the decoder PCB connects to the top 9 bits of the address bus, plus, possibly a line marked as B, and a clock as well

To confuse matters further the schematic diagram in the PRE option manual seems to show the decoder PCB being plugged into socket XA3 rather than PRE-XA2.
The PRE option manual is available on Terry O's site, but seems to make little sense. The 8718 manual I have makes no mention of the PRE option, or the PRE-XA2 socket.

Can anyone out there enlightem me as to how to install this option?
A couple of decent pics of a receiver with this option fitted will probably do fine, The only ones I can find on the net are not detailed enough. It should not matter if the receiver is an 8716 or an 8718.

I am pretty sure that my receiver should take this option, as it has all the mounting points for the filter assembly, and the PRE option is there ready to be "struck off" on the rear option plate, their just does not seem to be an obviously suitable socket to plug the decoder PCB in to...

The only thing I can think of is that the 8718-9 receiver has the ISB option fitted, and that the PRE and ISB options may be mutually exclusive, and that the ISB option is already taking up the socket, but it does not seem to be so.

Cheers,
Dave.S.