Tube Tester I-177-B

This is a post war tester for electron-tubes. There are of course war-time testers, but I did not obtain one, yet. 
As the goal of the hobby is to maintain radio's, I don't have any problem to use younger tools to reach this goal. 
My screwdrivers and soldering iron are also post war time!

Let's look at some pictures:

It comes in a handy metal case. I left the labels on it, that where attached when I obtained it. The labels state the original owner: the Dutch army. It was probably send to a warehouse for taking it out of service and for selling to some surplus-trader, eventually.
This is it's identification tag. The serial number is 1807, the contract or order number mentions the year 1952. Ever heard of Bluffton, Ohio?

I asked this question on saturday,  September 13, 2003 when I made this web-page. On Friday, August 24, 2007 I received an answer to that question from Darrell E. Groman. Follow this link for information about The Triplett Electrical Instrument Company, and, of course: Bluffton, Ohio. Thanks, Darrell!

In the lid the power cord is stored. A booklet is also there in which the settings for various tubes can be found. The two short wires with the rubber caps are for tubes that have a top-connection. The sockets can receive tubes, going back to the 1930's!

The booklet is dated june 11, 1951. In fact, it is only 49 days older than I am!

The green sticker indicates when the set is due for calibration again. The date on it is March, 14, 1978. This indicates the time this set has been in service, or in stock and when it was disposed of.

The socket, marked "E" has a double function. It also connects the MX-949 extension box, through which a large number of other, more modern tubes can be tested. You will see this later.

The meter in close-up. Used to calibrate the equipment to the line voltage and measure the amplification of the tube. Another visual indicator is a small neon-bulb, mounted under socket A. This is used to indicate short-circuits between the elements inside the tubes.
The interior shows robust construction. The black box is the transformer. The two valves are rectifiers. No printed circuit boards in those days! All components are wired by hand.....
.... and made to last a life time.

Want to know the details of this modification? Click this link for a diagram!

As I was searching the web for data of this fine piece of equipment I was lucky to find the website of Nolan Lee. Unfortunately, Nolan is no longer with us. A copy of his site is now hosted by Steve Johnson and can be found on:

This man really knew his tube testers! We came into correspondence and he coached me through some important modifications that you can see on this picture.

Nolan was a very helpful guy who had collected a lot of information as well as tube charts that are still available for downloading.

So now I have a good working tester and data on a lot more tubes than there are in the original booklet of 1951.

The MX-949-A/U extension box
The purpose of this box is to extend the number of sockets of the I-177-B. A cable connects to socket E on the tester. A large number of sockets are available. By using a number of patch cables and -sockets every pin of the tube to be tested can be connected to its proper element.
This box is made by Munston. Year of manufacturing is 1952. They made at least 6414 pieces...
In the middle the most modern sockets: look at X7 and X8!

Under you see the patch cables and -sockets. In case of a Noval-tube, you can connect for example pins 4 and 5 to sockets "F" and "F", which means "filament". "P" means "Plate", "G" means "Gate" and "K" means "Kathode".

The inside shows the same ruggedness. Wiring is treated with a sealing compound that must prevent moisture to damage the equipment.

That's the stuff that has this distinctive smell, that every surplus radio hobbyist loves.