Just bought a Cornell Dubilier Capacitor Analyer Model BF-50

[Tube TV]

There's a few highter wattage resistors in the circuit so it's likely suppost to be there. I just find how it's installed to be sloppy and not likely original.


All you'll need to do is parallel a 0.2 along with the 2.2 or whatever combination to get 2.4 mfd. The 2.4 mfd is one of the caps used for bridge reference and if it's off the dial will be off.

[vortalexfan]

Originally Posted by Tube TV

There's a few highter wattage resistors in the circuit so it's likely suppost to be there. I just find how it's installed to be sloppy and not likely original.


All you'll need to do is parallel a 0.2 along with the 2.2 or whatever combination to get 2.4 mfd. The 2.4 mfd is one of the caps used for bridge reference and if it's off the dial will be off.

Should I use a regular film/mylar cap in the 2.4 uF 60 V cap position or would a NP electrolytic work there? Just wondering.

[Tube TV]

Originally Posted by vortalexfan

Should I use a regular film/mylar cap in the 2.4 uF 60 V cap position or would a NP electrolytic work there? Just wondering.

I don't know how a NP electolytic would work and you'd likely only be able to get 2.2 mfd and have to mix and match to make up the difference. You could try it. Myself I would stick to a film caps. Heathkit used big war surplus oil filled caps for this capacitor on the old model C1 condenser checkers.

[vortalexfan]

Originally Posted by Tube TV

I don't know how a NP electolytic would work and you'd likely only be able to get 2.2 mfd and have to mix and match to make up the difference. You could try it. Myself I would stick to a film caps. Heathkit used big war surplus oil filled caps for this capacitor on the old model C1 condenser checkers.

I'll just see what I can come up with.

[dieseljeep]

Originally Posted by Tube TV

I don't know how a NP electolytic would work and you'd likely only be able to get 2.2 mfd and have to mix and match to make up the difference. You could try it. Myself I would stick to a film caps. Heathkit used big war surplus oil filled caps for this capacitor on the old model C1 condenser checkers.

I looked up the schematic for the Heath-kit C-1.
It's dated 1948! I think Heath-kit would've never survived without those war-surplus parts and tubes. A 12A6 for a rectifier? They used them in a few kits as both a rectifier and an output tube.

[Tube TV]

Originally Posted by dieseljeep

I looked up the schematic for the Heath-kit C-1.
It's dated 1948! I think Heath-kit would've never survived without those war-surplus parts and tubes. A 12A6 for a rectifier? They used them in a few kits as both a rectifier and an output tube.

Lol yeah. I forgot how they used the 12A6 as a rectifier. Just wire the grids to the plate and you're good to go. Come to think of it I think my tubes have JAN numbers on them. Those war surplus part must have gave Heathkit quite a edge allowing them to sell kits for far less than assembled equipment.

I loved mine till the transformer got some shorted turns between the some of the secondary windings and fried the wire wound pot for the main control. I still need to get around to rewinding the transformer. When it was working it was very accurate for both caps and resistors.

They must have got one sweet deal on all those post war parts. Might explain all the chicken head knobs on the equipment too. I wonder if the early scopes were running war surplus CRT tubes.....

[vortalexfan]

Originally Posted by Tube TV

Lol yeah. I forgot how they used the 12A6 as a rectifier. Just wire the grids to the plate and you're good to go. Come to think of it I think my tubes have JAN numbers on them. Those war surplus part must have gave Heathkit quite a edge allowing them to sell kits for far less than assembled equipment.

I loved mine till the transformer got some shorted turns between the some of the secondary windings and fried the wire wound pot for the main control. I still need to get around to rewinding the transformer. When it was working it was very accurate for both caps and resistors.

They must have got one sweet deal on all those post war parts. Might explain all the chicken head knobs on the equipment too. I wonder if the early scopes were running war surplus CRT tubes.....

All the caps used in this cap checker are capacitors I have in my stash the only capacitor I'm worried about being able to get is a .00112 uF cap that's in the 12A7 circuit somewhere, is that one a critical value or can that one just be replaced with a regular .001 uF cap and just be done with it?

[vortalexfan]

Well I checked the original 6E5 Tube (it was a coke bottle style tube) and it was a dud.

I also found a little black sheet metal shield looking thing inside the cabinet and I was wondering if it was supposed to be some sort of adaptor for the eye tube to adapt the eye tube opening to one of those slender non-coke bottle looking eye tubes.

[vortalexfan]

OK, so the 2.4 uF cap (C1) in this unit is listed as an AC voltage capacitor, is that correct or is that a typo in the manual?
I'm asking because there are no capacitors listed in mouser or digikey that's an AC rated cap at that value (no 2.4 uF 60 VAC caps.)

OK so an update, I removed the original 2.4 uF Cap from the unit and it looks like what they did at the factory was used a 2 uF 60 VAC capacitor in parallel with a .4 uF 600 VDC capacitor to come up with the 2.4 uF 60 VAC capacitor, which I ended up having to do something similar which was order a 2.2 uF 63 VAC (100 VDC) capacitor and then a .22 MFD 630 VDC capacitor which will be paralleled to come up with the 2.4 uF cap I will need.

unfortunately the .12 uF cap is turning out to be a tricky capacitor to locate (they list it as a capacitor that is available at Mouser but its not one that they keep in stock and the factory lead time is 22 weeks.)