Webster Chicago 180-1 Wire Recorder Restoration

[jcrubin]

I picked this up recently in good cosmetic condition.  The owner said there was no spools with it but i did find a complete roll on the take-up.  A mystery for later.  Dividing the project into Electronic and Mechanical. I worked mechanical first which was more of a complete disassembly, cleaning and oiling than anything else, only minor repairs. 






Mechanicals rebuilt tested and adjusted


The electronics would need more work than the mechanicals.  Id thought a tube overheated [convection not electrically] the output transformer, but tested in spec



When i tested the tubes, the 6x5 was completely shorted I knew the power transformer ate it. I really knew it when testing the motor and the unit was pulling 200W without a rectifier.



The center tap on HV was internal, non fuseable,a crappy design



Ive pulled enough windings to do the maths and evaluate the values, waiting for the new wire order to arrive.

[jcrubin]

The heater is a 28 turn center tapped coil. at 6.3v its .225v/turn.   The rest is not yet apart

Secondary shows about 484 give or take a turn or two.  Hard to compute given the operational range of the unit is between 110/120v

484 turns against 28 turns to produce 6.3vac is around 109mains voltage, 117V would be 520turns, 123v would be 547 turns.

HT is 1559 turns to center tap. given 547 turns for 123v to produce 6.3v at 28 turns, the HT would be almost exactly 350vac off Each lead to ground.  I believe this is my answer.

[jcrubin]

L3  Heater 6.3v      ~28T      ~3.64m     16awg
L2  Mains  123v     ~547T     ~66m        26awg
L1  HV      350v     ~3118T   ~406m      34awg
 
Bobbin 26x35mm EI-76mm

[jcrubin]

HV 350-0-350 wound and varnished



Taped, mains started



Mains wound for 110 117 123v taps

[jcrubin]

Final coil with heater windings added.