Saturday, December 27, 2014

Wonderful "Christmas Present" for Us Radio Guys on the Iowa

God bless the guys at PCS Associates!

During the process of troubleshooting the URR-74(v)2 receivers in the radio room, we've been terribly hampered by a lack of usable documentation.

The WJ 8718 receiver is very close to the URR-74, and we were able to find manuals for that receiver, BUT all the freely downloadable manuals were poor copies made into pdf's.

The worst part was that the schematics were copied with the copier magnification improperly set, resulting in a 1"~2" "gap" in the schematic between the two pages it was spread over!

You couldn't get them to overlap so you could tape them together and get a complete schematic, and in some cases it was cut so badly that complete components and/or circuit blocks were missing.

This makes it rather difficult to follow signals on the schematic, as you're never really sure where they're going between the two pages.

I finally found a place that still supports the Watkins Johnson receivers we have aboard the Iowa, and sent an email asking how much it would cost us to BUY a real, correct copy, stating that we weren't looking for a freebie, and would gladly PAY to get the manuals.

Well, this morning I received an email from a very nice gentleman containing the details of the ftp account he set up for me so I could download the manuals they have available!

I grabbed the manuals, and have been looking at them part of the day.

They manuals are crystal clear, and all the schematics are complete, and not butchered up.

I notified our Grey Radio Gang, and we're going to be working up a nice, official "Certificate of Appreciation" for this gentleman and his company.


  1. Outstanding! Can't help but wonder if that gent is an old RM... :-)

    1. Well, he sure knows WJ receivers!

      I explained to him what the problem was on the last receiver we haven't got fixed yet, and he came back in about half an hour and told us to not waste anymore time troubleshooting it, and just replace all the tantalum electrolytic capacitors on the A5 (synthesizer) board.

      I'm going through the manual know, and looking at the parts list for that board. I'll make up a list of tant caps, and then order them from DigiKey or Mouser.

  2. Yeah, sounds like he's been there... :-) Always had a love/hate relationship with WJs...

    1. I don't have much experience with them. They've always been kind of a "cult" radio to me, similar to all the "Green" (Army) radios that some people drool all over themselves for.

      The two we have working seem to be very good receivers, though, with multiple crystal bandpass filters, nice controls, very low noise floor, good sensitivity, and an assortment of output jacks on the back panel.

      I suppose they'd be pretty good for a general purpose 100kHz~30MHz receiver, but even used at $1500 they're a bit out of my budget these days!

  3. Way cool indeed. It's always a great day when someone goes the extra distance to do something nice for strangers.


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