Service manual wanted for Sanwa STR-307 Transistor Tester.

[kimbal]

Hi All;

I have acquired from a deceased estate a very neglected Sanwa STR-307 Transistor Checker - which has 3 vacuum tubes in it and an extremely rusty chassis. This would be the worst chassis I have seen from dry cell battery damage in my 40+ years servicing Electronics. The chassis had leaking D-Cell and 9 volt batteries left in it - and is now so bad the rust has literally eaten holes through the steel chassis.
The main case also needs de-rusting but is no where as bad.
Most people would happily scrap it - but I'm willing to give it a go, as I can't buy another one the same.

I want to restore the unit to working order and quite willing to make a new chassis from scratch.
I would like a service manual or at least a schematic diagram of the unit, so I can completely strip it down and rewire it from the service diagram.

Strangely, Sanwa made two versions under the same model number and I have both types.

One type is completely solid-state made on printed circuit boards having 8 knobs, which I believe is the second version; - while the 1st version is using 3 vacuum tubes on a steel chassis and is much larger with 7 knobs on the front panel; - YET - BOTH versions have the same model number and almost identical front meters.

I'm after at least the manual for the vacuum tube version; - but a service manual for the solid state version would also be useful. An internet search has revealed nothing that I can find other than a couple of pictures of the two versions.

Any assistance would be appreciated. - Kimbal Summers

 

[cosmonaute]

Hi Kimbal,

I've attached circuit diagram of solid state version. Unfortunately there is no register values, capacitor values and model number of Transistors.
But you can know all values by checking your real equipment.

Last week I got vacuum tube version at surplus shop in Tokyo Akihabara and then went to National Diet Library to find the article on "TRANSISTOR GIJYUTU (Technology),1968, March" magazine.

Please refer to some translation words as below when you see the circuit diagram.
S1-(1~6) FUNCTION
S2-(1~7) POLARITY
S3-(1~2) V-mA METER
S4 β RANGE
S5(Push Switch) Ico
*R (need for adjustment)
Rs (Shunt Resistor)
P (Pilot Lamp)
M1 V-mA meter
M2 Ico, β meter

On that magazine technical report were written which explains brief usage- but in Japanese only. I've attached these pages also.

When I go to Akihabara next time, I will go to the headquarters of Sanwa Radio to hear it. If you have any topic please let me know. I also want to repair it up.