[Premium-Rx] WJ 9040/8628-4-8/8626A

[w3jn at verizon.net]

I recently score this 9040/8628-4-8 RXer on eBay:  ttp://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=390119565012

It consists of the 9040 frame, the I/O module, PS, 50 MHz ref, a HFE223 HF extended, a 8628-4-8 20-512 RXer with extender to 1400 MHz, and a multicoupler for the video.  It does not have the handoff option, nor does the I/O module have RS232 nor IEEE488.  THe front panel has the "slideback" key to adjust the bias on the AM detector.  This frame apparently had a VLF converter as well as an IF/detector module which I don't have.  Radio comes up with errors 4,3, and then works fine (presumably the errors are the expected VLF and IF modules missing).

The IF came with 1/4/8/16 MHz IF filters, which are fairly useless these days unless you want to downconvert wide swaths of spectrum for analysis of the video.  Having a bunch of filters on hand I replaced the filters with 6 KHz/20KHz/50KHz/100KHz.   As a kind soul on the list had sent me a manual for a 8628 some time ago, I saw that the microprocessor knows what filters are installed via a diode matrix on each FM detector card.  So the first question is, anyone know how to configure the matrix for given filters?  I clipped some diodes by guess and by golly and found 7K, 50K, and "BW12".

Next question:  the manual I have doesn't have the schematics for the different FM detector cards.  There are apparently 3 or 4 different cards which are installed depending on the bandwidths desired.  After installing the different filters, the FM detectors don't want to align.  Could be the filters I had are off-center (believe at least the 6KHz filter is a bit off from 21.4 center).  It's extremely difficult to align because the IF module is in the middle of the radio, and 3 of the adjustments for each detector card are impossible to get to with the module in place.  So it's remove the radio from the frame, remove the module, adjust a bit, reverse, lather rinse repeat.  I guess the way to do it is build up an extender for the back frame ribbon cable that connects to the back of the module...  anyway a schematic of the various FM cards would be helpful.

Next, I have a 8626A HF receiver module (the one without the front panel) that I'd like to use with this receiver.  The receiver is here with me in Maryland and the HF receiver is at my place in Greece so trying it out will ahve to wait until I get back to Athens... but any possibility of this working seeing as the 8628 doesn't have the handoff option, and the I/O module on the frame doesn't have RS-232 (I do have a spare I/O module that has the RS-232 however).

Finally, there's a DIP switch on the back of the 9040 frame.  Any idea what this does?  There's no reference to it in the manual.

Any help/advice appreciated!

73 John/W3JN