Early
Digital Test
Equipment
Transistor Specialties Inc. Apti-Meter 361
Counter
 

Manufacturer:Transistor Specialties Inc.
Model:Apti-Meter 361
Year:1961
Schematic:RE
  
Max Rate:1.3 MHz (measured)
Display:NIXIE
Digits:6
Logic:discrete transistor Ge-PNP

An instrument from a smaller manufacturer but very well built.

 



- Unit Log -

Serial Number:398
Year of Manufacture: 1961 (Component date stamp 61??).
Date of Receipt:2005 Jul 31
State upon Receipt:Fairly clean. MSD NIXIE bad on 5,7,8, but readable. Timebase period incorrect on 10S gate.


Repair Date: 2005 Aug 4
Procedure:Cleaning completed, reassembled.


Repair Date: 2005 Aug 5
Procedure:180µF capacitor for 10S timebase has corroded lead. Replaced with 220µF. Trimmer adjusted.


Repair Date: 2005 Aug 6
Procedure:Power-on neon lamp internally covered with metallization. Bulb replaced. 18K limiting resistor replaced with 56K.


Repair Date: 2005 Aug 7
Procedure:V+a filter capacitor (bathtub) and bleeder resistor had been previously replaced, replacements were poorly installed (inadequate support). 8µF/220K replaced with 4.7µF/390K and moved from location next to crystal oscillator to unused area on power supply board.


Repair Date: 2005 Aug 7
Procedure:Feet had hardened and flattened. Replaced.


Repair Date: 2005 Aug 8
Procedure:Power cord replaced. Hole for strain relief had already been manually trimmed. New lockplate to keep strain relief from turning installed.


Repair Date: 2005 Aug 8
Procedure:Tiny oil drops placed on all control shafts from front.


Repair Date: 2005 Aug 8
Procedure:Fully functional.



- Unit Log -

Serial Number:399
Year of Manufacture: Component date codes indicate 1961 (6124 on trimmer resistor)
Date of Receipt:2005 Aug 20
State upon Receipt:Quite clean. Some long scratches on side panels. Unit functional but most NIXIEs have only partial ignition on most numerals. On 10S Test mode, unit only counts to 200.


Repair Date: 2005 Aug 20
Procedure:Cursory cleaning. V+a measures ~ 270V to 310V. The only completely good NIXIE, in digit 10^2, shifted to 10^0.


Repair Date: 2006 Apr 1
Procedure:After an hour or two of being powered on, NIXIEs are much improved.


Repair Date: 2006 Apr 5
Procedure:180µF capacitor for 10S timebase has corroded lead, same as on unit 398. Replaced with 220µF. Trimmer adjusted.


Repair Date: 2006 Apr 7
Procedure:Tiny oil drops placed on all control shafts from front.


Repair Date: 2006 Apr 8
Procedure:18K limiting resistor for power-on neon lamp replaced with 56K.


Repair Date: 2006 Apr 8
Procedure:Crystal oven not warming up. Heater wire open around bend on base at pin 3. New lead installed from pin and heater wire soldered to it. Heater OK.


Repair Date: 2006 Apr 8
Procedure:Feet had hardened and cracked. Replaced.


Repair Date: 2006 Apr 8
Procedure:Cleaning completed, reassembled. Fully functional. NIXIEs are OK after some warm-up.



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Early Digital Test Equipment
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