Tube Tester Readrite Model 432A - Made By Triplett

The Internet is a wonderful source for obtaining the most curious goods. On a on-line marketplace, this tubetester was offered. A few days later it was mine. I tested some tubes on it and they all came out to 40 ~ 50 % emission. I don't trust this outcome, so I will test the same tubes on my I-177 (made by Triplett) and decide than if the model 432A needs repair.

Some photo's can be enlarged: watch for the little hand!

Brand name: Readrite  (made by Triplett)
Modell: 432A
Serial no.: 10240
Sockets: 7:
ff-range: 1 - 110 V in 18 steps
Elements: 7 elements can be tested for shorts/leaks
Patents: not mentioned
Year of birth: 1930's ?
Accessories: 3 pages: user manual and 2 tube charts in lid
Manual: in PDF-format - click to download (not available yet)
Condition: Fair, working
Dimensions: H: x W x D mm


Wanted: Manual / Service documentation for this model

copy / PDF / original: all will be appreciated


This is the box that holds the tester. The wooden box is covered with a leather print, thin layer of some textile.

The lid can be taken off and holds three sheets of thick card board like paper, containing user instructions and a two tube charts.

The handle is of thick leather.

This is the frontpanel, carying all parts. Seven sockets, but not Noval.

Above the meter is a second, smaller meter. This smaller meter is used to correct the line voltage. A shadow of the meter needle is thrown on the semi transparent window and must cover the red line on that window. Thus one can correct variations in power line voltage, assuring that the proper voltages will be applied to testing the tubes. Clever!

In the upper lift corner one can see a hole in the cover. Under this hole, a neon bulb is fitted. This is the indicator for shorts and leaks.

The inside.

In the middle: the white rheostat, or large ceramic wire wound potentiometer for line adjustment.

To the right: the filament switch.

To the right: the element switch.
In the middle: the selector switch. This is a very complicated piece of thinking! In fact what it does, is, it determines what kind of tube is under testing and makes all necessary connections like plate, filament and cathode. Other testers (like the I-177) do this via a number of connector cables or (sliding) switches.

In the right bottom corner, the neon bulb can be seen.

Eye catcher on this photo is the pilot light. Behind it, you can see the little meter, used for adjusting the line voltage.
The component board. Some wire-wound resistors and some other parts. That's all.
The sockets. In the centre of the middle socket, pilot lights can be tested. Adjust the filament knob first, to apply the right voltage.
The controls up close.

Selector: determens the type of tube. Like Diode, Penthode, a.s.o.

Element: switches between elements to test for shorts and leaks.

Load: the load resistance in the plate line.

AC Volts: adjusts the line voltage to standard value for testing.

Filament: adjusts the filament voltage for the tested tube.

The box, inside view. Observe the metal inlays in the corners, to attach the front panel. The wedge on the bottom supports the transformer, hence the black stain.
And the insert in detail.

It is an easy to use tester. Tubes can be tested quickly. It lacks the 9 pin Noval socket, but that is due to the moment in history this unit was built. I don't know if it is possible to add other tubes to the list, in case one would make a socket converter, f.i. Octal to Noval. To do this successfully, one would need the technical manual. The manual could come in handy to determine the exact function of the selector switch.

(C) Photo's and text: 2010 - Van Zwam Computer Support - Velp - The Netherlands - All brands and brand names are property of their respective owners.