[TMC] SBT-1 progress Report #1

[telegrapher at att.net]

After setting in the garage (enclosed of course) for months until the 
summer heat went away so it was a workable environment i got started 
getting the SBT-1K back working.

Finally got all the necessary paperwork (manuals) and other technical 
literature rounded up and started trying to figure out all the 
connections.

Had to do a bit of cleaning inside particularly on the bottom of the 
unit where it had some rust.  Then 4 new feet with wheels to make it 
move a lot easier.

Finding the small twist lock AC connectors was a chore until i tapped a 
friend of mine's junkbox where he turned up a couple of them.  Also 
found the 3 pin twist lock for the PS-4 low voltage power supply in 
another box.

Pulled the APP-4 out of the rack and got the AC input wired, Aux. power 
(AC) wired also and then the pigtail for the PS-4 hooked up as well. 
More scouring and reading of the stack of paperwork told me how the 
terminal strip on the back of the PS-4 should be hooked up.  Nothing simple.

Put the PS-5 HV supply in the rack and hooked it up as well.  Gawd that 
thing is heavy.  Good thing it is only a couple inches from the floor to 
the slide rails in the rack.

Plugged the AC in and turned on the main breaker on the APP-4.  No 
smoke.  Things are good in life!  Turned on the main power on the PS-4. 
  How come i only see 65V ac on the meter?  NOW what?  Adjustment range 
is from about 42V to 67V.  This is not good.  Power everything down and 
unplug AC.  Pull APP-4 to check wiring to see if i split something. 
Nope.  everything is right.  Put it back to together again and reinstall 
in the rack.  Trouble has to be in the PS-4.

Pull the PS-4 out of rack again and tilt it up, locking it into place. 
Now lets see.......  This was actually the 2nd time i'd looked under the 
chassis.  Wiring on the auto transformer didn't look right the first 
time and this time i knew it had to be something to do with that 
particular item.  The auto transformer should have 3 wires on the -0- 
voltage point and 2 on the 115V point.  In this case of the two wires 
that should have been on the 115V point, only one was there and the 2nd 
wire was attached to the 230 V pin.  Took wire from the 230V pin and put 
it on the 115V pin and closed things up again.

After putting things back together i again applied AC.  This time i got 
up in the 115V range and was able to adjust the meter reading to about 
117V.  Life is good.

More------

Larry
W0OGH