Voltage regulator capacitor value?

[cantankrs]

Hi Jesse,

Am I right in thinking you don't mean a 78XX/79XX voltage regulator, but one from your Sexton similar to the pic attached??

Alex McDougall

[Jesse Browning]

Alex; You are exactly right. The circled item is the culprit. Do you have a tester? I wonder if all of them are bad after 65 years. Most of the capacitors on the WWII radios are still good. A few types, and manufacturers, though can be expected to be bad. Jesse.

[cantankrs]

Hi Jesse,

1 uF (Microfarad) for the General Lee/Grant Medium M3 Tank.

See pic for confirmation - sorry about the poor quality.

Alex

[Jesse Browning]

Thanks to both Alex's for the solution to my problem. While we are on the subject, the voltage regulator I have from another vehicle fits loose in the base. There doesn't seem to be an adjustment for this. Any one ever add shims to one or the other side? Jesse.

[Alex Blair (RIP)]

Originally Posted by Jesse Browning

Alex; You are exactly right. The circled item is the culprit. Do you have a tester? I wonder if all of them are bad after 65 years. Most of the capacitors on the WWII radios are still good. A few types, and manufacturers, though can be expected to be bad. Jesse.

Jesse
To test the capacitor,take a analogue ohm meter..One with a needle..not a digital..
Turn the ohm meter to the highest resistance and hold one lead to the output lead and one lead to the case(Ground)
If The capacitor is good,the needle will jump halfway up the scale and slowly fall back towards zero...
What is happening is the capacitor is good and is being charged to 1.5V or the ohmmeters battery strength..
This means the cap is good..
The capacitor is only good or bad..There is no in between..
To recheck..reverses the leads and the needle should jump again and repeat the charging,but with the opposite polarity.
ALL capacitors can be tested this way..I been doing it for 45 years and it works fine..
The capacitor size for both magneto and spark coil capacitors range from 0.2 microfarad to 0.33 micro farads. Almost all automotive distributor coils use a 0.25-0.29 microfarad capacitor.
Add a heat sink around the case to get rid of excess heat.
You do great work so any little help I can offer..I'm in..
By The way ..the capacitor acts as a voltage ground bleed and minimizes the arcing at the points when they open and closed, but its main function is to provide a circuit path for the coil after the points open and to speed up the collapse of the magnetic field..
You can really burn the points out when the cap fails.
You can also parallel the caps to give you longer use and better heat control..but hook them up with like polarity or they will burn out instantly..
Values of capacitor and equal to the total values divided by the number of caps in parallel. ...so 1 micfarad + 1 micfarad in parallel = .5 microfarad..or just where you want to be.
Here are the formula and some explanation..I find all this shit after I type all this out..
http://www.electronicrepairguide.com...apacitors.html

Here is a good explanation and a good simple wiring diagram .
Draw another Capacitor identical beside the one pictured in the wiring diagram, connect the leads and ground the case,shown as ground symbol and away you go .

http://mgaguru.com/mgtech/ignition/ig108.htm

After writing all this I found this..It never fails..

http://www.smokstak.com/articles/capacitors.html

Read this and you will be the smartest capacitor guy in Indiana.
(Except when I'm in Zionsville)

[Jesse Browning]

Alex; Great information. I used to spend a lot of time restoring the old tube radios; before the armor came along. I was trained in electronics in the USMC in the early 80's. Fascinating stuff, the old tube radios, especially the military sets. I have a tube powered capacitor tester. It's really ancient, but works perfectly. Jesse.