Want to make my own Biasing test probe for EL84

[blindboybenton]

Good day too you all

I have the TAD bias master, Great Piece of kit. I don't have any trouble with the test probes for 6L6 or EL34 as when there break i cut into the side and replace or repair the wires. cover up and all is well. my local supplier can sell me some EL84 probes, But they are not cheap and break very easy. The last set broken in 1 month



I know i where i can get stuff to build my own EL34 probes, but i can't source any EL84 probes Just the bases so i can make my own that can be used with the TAD Bias master

any thoughts people

BBB

[gearhead63]

I got some socket savers, a plastic box, wire, and banana jacks/plugs.
I plug it into the amp, put the tube in the socket on the box.
Now I have a 1 ohm resistor in it so I can use my DVM, and
I tapped into the plate circuit so i can read the voltage without taking the amp apart.
It's not pretty like an expensive store bought unit, but works great!

[tedmich]

https://tubedepot.com/products/9-pin-socket-saver

you can do something fancier with Belton sockets and PVC pipe or conduit. Does the TAD give plate voltage at full or with a 1:1000 voltage divider and mV readings? The later arrangement is MUCH more safe IMHO.

Tubetown made a PCB kit but it seems to be gone now, see:
http://www.tonegeek.com/musicgear/bi...e-for-el84.php

[blindboybenton]

Thanks ted The tubedepot item is perfect. I can make them into what i want

[Chuck H]

Does the TAD give plate voltage at full or with a 1:1000 voltage divider and mV readings? The later arrangement is MUCH more safe IMHO.

Good call Though I might go 100:1 for better meter accuracy.

[Tom Phillips]

Inside the 9 pin socket saver

Here is a photo I happened to have showing the construction inside that socket saver.

[Chuck H]

Here is a photo I happened to have showing the construction inside that socket saver.
[ATTACH=CONFIG]33236[/ATTACH]

Yes, it's a complicated device. When I saw photos of them on line, making a Noval 9 pin bias test unit was probably the first thing I thought. The only hitch is finding a good way to stabilize the pins with the circuits attached. I thought about sealing up the female end and getting everything stuffed into place followed by a generous dose of epoxy resin.

Oh! I hear you can use them to preserve your sockets too

[gearhead63]

If you try to put the components INSIDE the noval socket saver........good luck.
I soldered all my wires into the top of the SS (which you plug into your tube socket),
then into my box.

And using another socket saver that I took the bottom off of,
I soldered my wires to it and inserted a resistor and a tap off the plate
to a separate banana plug. All inside the box. I epoxied the plug into the box.
Don't have to worry about not enough room to insert your probe connector and a tube on top of it.
Now I didn't insulate the top of my probe socket, and I do have a high voltage tap that extends outside the chassis,
but I know better than put my fingers on any of it or make connection while powered up.

[blindboybenton]

Thanks for the info. Im using the tad bias master and need to get the bits too make my own probes. Ive found them at Tube Depot and ive ordered enough too last me about 5 yrs

BBB