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6c33 Testing on Funke W19

PostPosted: Mon Sep 10, 2012 9:38 am
by marco_esp
Hi all, I am looking for guides on how to test 6c33 on Funke W19. I was thinking of an external box with septar socket and heavier transformer for Fillament and use an existing tube location to connect this box. Any guidance will be really helpful.

Re: 6c33 Testing on Funke W19

PostPosted: Tue Sep 11, 2012 11:53 am
by TubeKing
It should me more or less a cable with octal socket and a seperate box for the socket and external power connection.
Then to see what voltages you need and if the Funke is able to provide these including the measure range, adapter should be something like you find here

Re: 6c33 Testing on Funke W19

PostPosted: Tue Sep 11, 2012 1:47 pm
by marco_esp
Thanks, yes this is what I have in mind... Any recomandation on how to realize it? 12.6 Transformer with filaments in series? Which tube cart is the closest to the 6c33?

Re: 6c33 Testing on Funke W19

PostPosted: Wed Oct 03, 2012 4:06 pm
by Doc10
If you have a Funke W19S, it already has the 6C33 socket, but unfortunately it is connected such that can not plug a 6C33 tube in. I wanted to do so too, but not all connections can be made. So the option may be to change the wires that are soldered on the socket, and then you can get it going. So of course all other cards for that socket won't work any more, but do you need that? The heater you should put in series, to prevent excessive current. I am pretty sure, the internal transformer can't do this. Perhaps at it's limits at 12.6V, but I would not risk it. So you need a small 12.6V transformer that you put inside. You can wire this 12.6V directly to the 6C33 heater connections on the socket. Or, if the voltage is really identical, you can connect it in parallel to the 12.6V transformer inside the Funke. That is elegant, and would boost the capabilities of the internal 12.6V.

For a W19 it doesn't have this socket. (W19S has). So with a W19 you might throw out one of the existing sockets that you are not using, and put a 6C33 socket in there.

The whole rest of the tester should be perfectly able to test a 6C33, at full power. It is MADE for it!!! So really heat up the anodes of the tube to it's full limits, in a way no other tube tester can do. You can consider AC plate voltage also, this enables much higher current. You can check with the AD1 tube card, how that is done.

Alternatively you could make an adapter box, with a 12.6V transformer inside, and this box plugs into the main deck with the 4mm BANANA connectors.

All in the end, you need to make a nice card yourself. So in the card are also the holes for the BANANA connectors. Or the holes for the normal small plugs, in case you build the socket inside the tester.

The most imporant test for a NEW 6C33 is, heat the tube to its full maximum dissipation, and once HOT, you check for grid current. (Rotate the TEST knob, and look for any readings in the red field). It is the main weakness of this tube. Used tubes should be checked for emission. There is not good help for how to set the card, you have to do so by learining this yourself, by using a new tube and find a good test point. Then, also use an old tube that you know is weak, but "just ok". From this tube you derive the famous point: "Good begins at ...mA"

If you have no idea what all of this means, I would say don't do it. But when you understand well enough how the W19 works, this is a good guide for beginners here, and sure is, the W19 is like "made" for this. One of the very few testers that can handle a 6C33 at full power.