dont use a 2n3055 of course. Make the 220 Ohms larger. and use some kind of 20V zener diode on the output. Adjust until you get the required voltage.

 

I have some Zener diodes, whould I just place it in line to the positive side of the device, then connect to the battery?

Yes, either line.
Use a zener value equal to the voltage you want to dump.

Remember to connect backwards or it will just dump .6V.

If you decide on rechargable. I have no use for these.

They came with some other misc.

Probably not worth the postage.

 

Time for a break.

I will re-wire with (3) 9v batteries and a Zener Diode tomorrow, and post back.

Thanks for all the input so far.

 

It's working both as a transistor and diode tester.

The calibration knob is controlling voltage.

I have 3 9v in series.

The biggest problem is the little caps that snap to the batteries.

I think I'm going to have to spring for a single 21 1/2 volt battery, since it is soldered in place.

Then I don't have to worry about these little snaps getting loose.

I'm still interested if anyone knows more than I do about exactly how to use it.

I'll look on the web and you tube as well..
Thanks again,
Until next time,

Gary

 

buying a new battery for 40 dollar is weird- you can get a new tester for less than that.

 

Good point!
I had earned a little extra money, and bought a few old meters and testers for fun.
This was the last one.

Maybe I'll do what you suggest and save this one for my Grandson, although he really wants to become a Mechanical Engineer.

Now I'm thinking of putting an on-off switch on it (I have a nice old switch, with an external mounted On-Off plate), and then simply wrap electrical tape around the snaps / batteries, to keep them secure. Then when the cover is put back on, it should look nice, and I won't have to worry about accidentally discharging the batteries.

Thanks again for every ones input.

 

All done,
It works great, and I found a couple of videos on Youtube to help get me started using it. I've checked diodes and transistors.

Here are a couple of photos,
It's a Knight, made by Allied Radio, Chicago.

The meter makes more sense now that I read it closely.
L-R it reads 0||||.2||||.4||||.6||||.8||||1

The old switch (an add-on) works good, and looks original.

Thanks for your input.

Gary

 

I found some info at radio museum. It was made and sold in 1963, as a Knight-Kit.
As a kit, it cost $8.95, factory wired cost $13.95.
"Checks leakage-to-gain ratio and noise level of junction-point contact and barrier transistors. Also checks Germanium and Silicon diodes. Forward and reverse current conduction selenium rectifiers, continuity and shorts. Has Leakage - Gain switch: forward current control, calibration control, separate sockets for NPN and PNP transistors."

Apparently they sold a lot of different kits.

I found a manual on-line for $40.00....................

I guess I'll just have to pass on that.

Very cool though.

 

Last bit!
I found an original assembly manual on Ebay for $7.95, with free shipping.
It includes details on how to select and test various components as well.
So I will have the whole package (minus the box).
Nice find.....