Faithful readers will recall that in the previous issue, Newsletter No. 29, Bill Ruck of the MRHS Maintenance Department reported on his battle with the WCC keying panel at the receive site. When we last left Bill he was dealing with the great frustration that derives from incomplete documentation or, worse, documentation that's not correct. As you will see, this situation is taking its toll on the great man, causing him to hear voices and mutter to himself. But in spite of all he perseveres.
Let's listen now as we hear Bill say...
The plan was to check the system and install a new cable so that the WCC keying lines could be connected to the RCA 901 tone sets. I set up but could not get it to work. Much testing later I gave up, asked MP to step aside and removed the CW Position 1 WCC panel.
On the bench it worked perfectly. But back in the room I could only get intermittent keying. Grumble.
Rather than continue to annoy MP I pulled the panel out at Position 2 and started testing. I could get some lines to key some of the time. Grumble. Mutter.
Back and forth between the blue WCC rack and Position 2. Grumble. Mutter.
MP likely was contemplating how to get ahold of the guys with the big butterfly nets and jacket with very long sleeves. Then the voice in my head said "MEASURE THE VOLTAGE ON THE LED / RELAY BUSS." "It's just 5 V." "DON'T ARGUE WITH ME" Grumble.
I went back to the shop and got my trusty VOM. The voltage was 3 VDC. "But there is nothing between the +5VDC power and there except a switch contact." "MEASURE THE VOLTAGE AT THE POWER SUPPLY PIN". Also 3 VDC. "But there is nothing between there and the +5 VDC power supply other than a long piece of wire." "STOP ARGUING WITH ME AND MEASURE THE POWER SUPPLY". I went back to the WCC rack, removed the power distribution panel and disassembled it enough to get to the power supply. Ah-hah! It was only making 3 VDC.
The grain-of-wheat bulb in my head started to glow. Dimly. Went back to the shop, got the bench supply that I had been using that had a +5VDC output and wired it to the power wires. Now all WCC lines keyed properly. The 3 VDC was enough to get the LEDs to light but not enough to reliably pull in the relays that switched the keying lines from the wheel to hand keying.
|Bill is willing to do just about anything for The Cause. Here we see him descending into a cable vault filled with what we call "rat soup" due to the dead, floating vermin it contains. |
Also noted that with really 5 VDC the LEDs in the WCC panels are much brighter than they were before. Duh-oh!
By then it was late enough that it was time to clean up, so I did not get a chance to move forward. The Acopian 5EB200 "AC to DC POWER MODULE" is a pretty solid lump. My experience in the past is that these are potted and can not be repaired. A +5 VDC supply at 600 mA (I measured the current with all 10 lines selected at +5 VDC) is not hard to make; all I need is a 7805.
Will check Ye Olde Junque Boxe and see what I can find to make a replacement that may fit into the power distribution panel. Oh, by the way, the wiring on that panel does not resemble the schematic. Welcome to KPH
This is the sort of thing that drives grown men mad. We figure we'll be able to squeeze a little more work out of RK before we have to ship him off the the Old Radioman's Home where he can rest comfortably and his mutterings will be deadened by the padding on the walls of his room.
No, but seriously, who among us has ever wielded the probes of a Simpson 260 and not run into such frustration? Right, we've all been there. The difference is Bill simply... will... not... give... up. And that's really what it takes, combined with some really top drawer technical chops, to keep The Project moving forward.
If you've been following these reports of our activities you know that all of us, including Bill, are volunteers. And Bill, yet to retire, is trying to make a living in between sorting out the arcane systems of KPH. He makes the trip from San Francisco to remote West Marin and even brings morning buns along to be consumed at morning Services of the Church of the Continuous Wave at Bolinas. It's really hard to ask for more than that.
Of course we all participate happily in this project and feel lucky to be involved with The Cause. But you know... a little assistance from our fellow True Believers would be a great help. It allows us to make purchases of needed parts and equipment that otherwise would have to be paid for from our personal bank accounts - which we are happy to do when needed.