Judson Magneto - Scam or the real deal?

[John Moxon]

[Takeda2]

Back in the 70's I took one of these apart and found it was a fraud! The uppser device is a stud diode, that is connected in series with the coil. The emitter and base of the T03 transistor aren't connected to ANYTHING!

[Old n' slow]

I bought one in about 1967 and put it on my 1961 Chevrolet . I could see no difference in performance or gasoline mileage , it did burn out during the first few months and left me by the side of the road . Luckily I had the original coil in the trunk .

To this day I carry a variety of small part spares in my VW's .
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Currently own : 1969 Beetle w/ 1600cc, Single Port, Solex 30 PICT 2, Dist. 113 905 205 T, stock exhaust.
All my daily drivers gone but not forgotten;

1964(sunroof)1967 & (2)1968 Beetles , 1968 Squareback , 1963 (23 window )Deluxe Sunroof Bus , 1969 Westphalia camper, 1974 Dasher , 1985 Vanagon , (2) 1981 Rabbit Diesels & a 1991 Jetta Diesel .

[Jacks]

Very helpful. Thank you.
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Jack Staggs
Actual name

[John Moxon]

[Jacks]

[John Moxon]

OK so does the Judson Magneto add anything to the performance of your VW...maybe it does, maybe it doesn't.

I have a friend who back in the 1960s ran the Supercharger Department at Conshohocken and this is what he told me about the Judson Magneto...

[macwzrd]

I used a judson Magneto (probably one of the first)on my Austin Healey 100-6.

The big Healey had broken rings on the some of the pistons and continually caused the spark plugs to foul and make the car miss. And yes, I did keep increasing the 'heat range' of my spark plugs finally using a very hot burning NGK Platinum plug, but it was still not enough.

Once I added the Judson Magneto, and a new aftermarket electric fuel pump the car ran without any major plug foul outs. The combination all contributed to the plugs firing hot enough to keep the plugs clean enough to eliminate the missing.

I wasn't too concerned about the engine rebuild, since I had already purchased a spare engine. But, in this case the Judson Magneto helped me.

[vwhelmot]

Anyone had any problems with the Judson coil breaking down when hot? I may have an issue with mine or do they just work or not and not be intermittant?

[John Moxon]

Yes the Judson Magneto can be used on 6 or 12 volt...no difference in the unit. However if using on 12 volt you should fit a balance resistor. The Ballast number given by Judson is obsolete, but your local electrical parts supplier should be able to cross reference it.
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John.
Judson Supercharger Information on The Samba
My 1958 Shorrock Supercharged Karmann Ghia
Stop dead photo links! Post your photos to The Samba Gallery!

[pig-pen]

hello there... the above installation instructions suggest there is no difference between the a 12v and a 6v unit....

Is this the case... can they be used on the different voltages???

[John Moxon]

[Braukuche]

I just came across a Judson Magneto in a parts haul and am thinking of using it on one of my 36hp vehicles. Does anyone know what the wiring is supposed to look like?
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Go Reds! Smash state!

Retirement is here!
1956 Ghia
1959 SO-23 Westfalia
1960 double cab
1960 Baja Bug
1963 stretched double cab
1962 Golde sunroof Ghia
1963 356 B coupe
1963 Notchback
1967 21 window less rusty now

[Fred Winterburn]

Folks, I'm new to this forum, but I have an interest in ignition systems. The Judson magneto was not a hoax. It may have only been a minor improvement over the stock system, but it was not a hoax. I have a book that explains its operation and shows the circuit. The purpose of the Judson magneto other than looking cool, was to take the inductive load off the points so they didn't burn, and let a transistor in series with the points do the actual switching. So, despite the points handling all of the current just like the transistor in series with it, they were only used as the trigger. Since the transistor removed the high voltage inductive kick from the points, and the addition of a very large capacitor to prevent any residual burning, points would last a long time. A couple of zener diodes were also incorporated to protect the transistor and I assume that the device with the 'siamese twin' logo on the top of the transistor is a pair of zener diodes incorporated into that heat sunk unit. The Judson is unlike the 'transistor switch' ignitions of the time which kept points current low and only used them as a trigger in parallel with the transistors driving their bases. In the Judson, the points drive the transistor base and are also in series with it. The transistor on the Judson turns the current to the coil primary off very quickly as soon as the points start to open. This should make starting easier with a Judson as the coil primary current collapses more quickly at low engine speed than it can with slow opening points. The coil has a very large turns ratio of 350:1. It's an odd set up, but I have to admit that it does look cool. Fred

[mightymouse]

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Nothing can stop the man with the right mental attitude from achieving his goal; nothing on earth can help the man with the wrong mental attitude.
Thomas Jefferson


Note to EVERYONE.
Know your ZDDP levels or you WILL lose a cam and lifters.

[John Moxon]

[gt78]

Me too!!!

And I had my coil flown in from the States

I guess the 4 months have gone now..have to make a wall decor of my own!

Wonder if the supercharger even worked?

[xilly]

awesome info

I'm been scammed!!!!

William

[Zelma]

[lupin..the..3rd]