Jackson 103 Dynamic Tube Tester

[danrulz98]

My first project, yay!

So, I have this old tube tester. I'm guessing from around 1949 or so.

I'm hoping its a relatively simple project to start off with.

Its in pretty good condition as it is, and it even works.
I've made a short video asking about it: http://www.youtube.com/watch?v=Im7wcwQQCVA

The only problem it seems to have are the scrolls with all the information on them: http://www.youtube.com/watch?v=r0nj4FstzGM

Well, I think I've made my first mistake tonight.
I stared at a big wax cap for a while and couldn't find any information written on it. I stripped off the first layer of wax (disgusting) and found the information down there.
Its a 400 volt cap, but I don't know where the capacitance is. I might have stripped that part of it off...

I did find where someone else was restoring one of these and the cap they replaced this with just says "104k 630 v" on it.
I'm assuming this means 104K uF at 630 volts?

So, any input on that or the scrolls is appreciated.

[bandersen]

Originally Posted by danrulz98

... I did find where someone else was restoring one of these and the cap they replaced this with just says "104k 630 v" on it.
I'm assuming this means 104K uF at 630 volts?...

The 4k is shorthand for "4 zeroes" and it's in picofarads. So, you've got 100,000 pF or more commonly written as 0.1 uF @ 630V.

Good luck

[danrulz98]

Awesome, thanks!

Now, hmm.. I feel like an idiot asking about this but how do you find the power rating of resistors?

[bandersen]

Good question. Ideally, you'd have a schematic and parts list to work off of.

Otherwise, you can go by the type of construction used and size. Here's a comparison of some common types.

Left to right we have 1/2 W, 1W and 2W carbon composition. Last it's a vitreous enamel 10W power resistor. Generally resistors over 2 watts are marked with a wattage rating. Hope that helps.

[danrulz98]

I've looked around for a schematic, looks like there's nothing out there for the 103 specifically.
Maybe I'm not looking in the right places.

Hmm, I want to say most of my resistors are 1 watt... Might as well get 1 watt resistors to be safe, right?
I know there's a 2 watt resistor in there, its the size of your 2 watt resistor there. Then looks like I've got two 10 watt resistors. All they have written on them is the resistance.

The components in this thing aren't very well marked. I wonder if the markings got worn off somehow.

[bandersen]

Could you post some pictures ? It's possible they weren't marked or they faded.

[danrulz98]

http://tinypic.com/a/25nhx/1

I took a lot of crummy pictures...

The big 3k one is shorted, there's even a nice little burnt spot on top of it.

(Standard ball point pen for reference)

http://i48.tinypic.com/29lmw5k.jpg

http://i46.tinypic.com/1237fo6.jpg

I think these are half watt

http://i46.tinypic.com/2jahjyf.jpg

I think this one under the power resistors is a two watt.

http://i49.tinypic.com/1fu177.jpg

[bandersen]

I think the Tru ohm are 5 and 10 watts.

Yes, those are 1/2 watt.

Not sure about the last one could be 1 or 2 watt. Might as well go with 2 watt.

[danrulz98]

Yeah, they're cheap enough.
Sorry if it seems like I'm asking a lot of questions, I'm not very familiar with older electronics. :/

Also, those paper caps... are the second most disgusting thing I've pulled out of something electronic...
Second only to a mummified mouse I found in a computer...

[bandersen]

Yuck - haven't found a mouse yet - only empty nests. Try restuffing paper caps some day - now that's gross

[danrulz98]

http://downloads.danh.in/index.php?dir=tubetester/

Made two PDFs of the scrolls. tubetester.pdf is a "text" version of the scrolls and original.pdf is the raw images of the scrolls.
Hope these are helpful to somone

[Buzzsaaw]

looks like a meal I was served at a local greasy spoon. Yummy!
Buzz