Power Supply and Murphy

[WU2D]

First the lessons:

1. Power supplies do not like being near the floor in damp basements.

2. Unplug all power supplies when not in regular use.

3. Kill your breakers when you leave the shack.
 
4. Finally: Build all power supplies like they might burn your house down.

Murphy was loose today. I had a great plan to meet with WA1QHQ Mark and W1VKZ, Andrew at the MIT FLEA in Boston and we were just arriving when I got a frantic call from the XYL. There was a strong smell coming from the shack! More than an hour away I told her to pull all of the outlet strips and kill the two (marked) breakers to the shack. This seemed to calm things down and the smoke detectors never fired so she watched. By the time I got home, no more problems but I had an awful smell in the shack. Honestly I could not tell if it was electronic or a wood burning smell and that was scary. I have knotty pine basement walls.

At this point I started emptying the shack and ran a fan out the bulkhead. It took 2 full hours of diligent searching before I found the culprit. It was a Frankenstein power supply that I had built for my Super Pro. It was basically an old Ballantine Voltmeter foundation made into a power supply. This supply was made in haste. It was fused correctly and the ON -OFF switch was OFF. But that supply should never have been plugged in. the failure was a PVC wire that was banjoed across the terminal that happened to have AC hot on it thus slowly failing and turning the PSU ON over time. Unloaded, the PSU eventually became unhappy and the transformer developed a shorted turn on the secondary, became very hot and spewed forth the brown goop. It did this precisely 2 Hours AFTER I had been in the shack (before leaving) and I was already in Boston so I missed the blessed event.


The XYL said the only reason she did not call the fire department was the fear that they would take one look at the shack and put RED TAPE around the house - Hi.

Mike WU2D

 
   

[W3SLK]

Lucky you. I did have the fire company come when the LVPS transformer went on the Globe Chump. It was my engine company that responded. How embarrassing.

[KA2DZT]

I just rebuilt a power supply for a SP-210.  The supply looks like it belongs powering a xmtr instead of a receiver.

Try to use Teflon wire wherever you can.

Fred

[The Slab Bacon]

Simple cure! ! ! !

Just install a master disconnect switch that cuts off power to everything in the shack. Short, Sweet, and Simple! ! ! ! ! ! ! ! !

All of the old vintage gear that I use, I would never think of leaving it hot while I wasn't around.

If you make it easy to do (kill all of the power) you wont mind doing it all of the time until it becomes "force of habbit"

Always remenber that Murphy is not kind, and definately is not your friend.................

[WA1QHQ]

Wow Mike,

I was wondering what happen to you, Colin and I cruised through the flea market a couple of times looking for you, never did see Andrew. The flea was smaller than I have seen in years past probably due to the month more than anything else. The BC-348 was still there when we left, bring an allen wrench with you next month.

Mark WA1QHQ

[Opcom]

Everything but the clock is disconnected by one double pole switch on the front of a rack. It is conspicuously marked "master shut off" for the benefit of others. Behind this are a couple of big contactors that do the work. I don't mind the hum or the ker-chunk. Those are the sounds of safety.

[WQ9E]

The radio room has its own separate breaker panel fed through a disconnect switch.  The only circuit on the main (non-switched) panel is the main fluorescent lighting.  The 120 volt gear in the ground floor parlor is plugged into outlet strips that are switched off when not in use and the 240 volt feed to the heavy stuff (Desk KW, Viking 500, various amps) has a separate shutoff switch.

I would never trust the switches or wiring in vintage gear to be connected when I am not around.  I am willing to do without the drift canceling features in my SX-101A and HQ-170A.

[AJ1G]

Way back when we first moved into this house, I was running  a Viking II in the basement shack I still use.  One hot humid summer night, I powered it up but then had to go out and do something in the yard.  Went back in about an hour later and there was a huge pall of acrid smoke hanging in the overhead.  The normally white light of the bare ceiling fixture light bulbs was an ugly yellow.  Smoked the LV B plus transformer somehow. 

[The Slab Bacon]

I would never trust the switches or wiring in vintage gear to be connected when I am not around.  I am willing to do without the drift canceling features in my SX-101A and HQ-170A.

THAT SAYS IT ALL! ! ! ! !

Rodger, I agree 100% ! ! ! !

It's not worth losing my house over the effort to pull a switch!