I think the question transformerless has been mis-interpreted? A tube tester does not require anything other than a rectifier. It can be Metal, Solid State, or a Valve.

I have a transformerless type with a similar switching method. The chassis can be live and dangerous. The one I have, if used on the mains, without an isolation transformer, it can trip the earth leakage trip (RCD) in the fuse box. (not really intrinsically safe)

The second octal socket may actually have finer pin holes and be a "loctal" and there are loctals in some Australian radios.


The valves roughly follow a convention. However, if you compare the pinouts of valves (Valve data book) to others that may be listed, then you can get some idea.

The aged VCT I have does have a section on "unknown valves".

Marc

You didn't mention socket 3.

It appears the sockets are hard wired and cant be switched. That is why you have multiples of the same socket to cater for the differences with the heater/filament pin-out. As this unit has only one miniature 7 pin socket you wont be able to test those battery valves you mentioned before. The 7 pin battery valves dont have their filaments on pins 3 & 4 like the AC heater types.

For testing a EK32, I'd go for load setting "D".

Socket 3 is 12 pin

Marcc mentioned a Lockal socket. Does your Hickok have one? Locktal valves are similar to Octals, except the pins are thinner and the spigot has a groove in it to lock in to the socket. The type numbers of Locktals usually start with "7" & "14".

In regards to testing unknown valves:-

Sel A goes to the cathode.

Sel B goes to the 1st grid.

Lockout locks out pins where the valves 1st grid is on multiple pins.

Fil D for 6.3 volt valves.

Fil E for 6.3 volt valves that have higher filament/heater current.

For example:-

A 6AQ5 pinout is 1- grid 1, 2- cathode, 3 & 4- heater; 5 anode/plate, 6- screen grid & 7- grid 1.

As you can see, a 6AQ5's grid 1 is on both pin 1 & 7. So the Lockout is on "7" (see below). If pin either 1 or 7 is not locked out it will show up as short.

Sel A is set to "2" -cathode pin.

Sel B is set to "1" - grid pin. You could also set it to "7" but then you would have the Lockout set to "1"

The Open Test etc., is set for all used elements except the heater/filament. 1, 2, 5, 6 & 7.

Not sure how to determine the load setting except for perhaps comparing the un-listed valve with a similar type that is listed.

There are two testers I have mentioned

The VCT is 1938 made by "Paton"and there are variants of it. It is 6V /240V. It has no minature sockets but the newer versions did.

The other is marked a "Tech" this is the dangerous one and only has two sockets. I mentioned it as the Americans are one lot that had a bad habit of making radios & test equipment without transformers.

These often had a capacitor from the mains (praying that it was Neutral) to a metal case. I have modified a couple of devices like that recently and they had transformers?

Don't know how this sort of stuff was let loose here?

As the VCT is "Hard wired" to the sockets it has two octal sockets, one for rectifiers and another for the conventional heaters/ filaments pins 2 & 7. The rest had to be done wirth adaptors.

As pointed out the 230 may be similar, with it's duplicate sockets. Does that manual have the circuit?

Also, as it is American; It may be worth going to the American Antique Radio Forum http://antiqueradios.com/ which has a series of specialised forums, one of which deals exclusively with test equipment. I would have strong doubt as to you failing to get info from there.

There are a few forums that deal exclusively with brands

Marc