Sun MDT distributor tester

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69DodgeMan said:
I don't think it is too terribly different than the later models. It is direct drive instead of a belt drive. The wiring is probably a little more "primitive" but I'll bet the basic concept of operation is very similar. I've a feeling that the power supply (I think its a high voltage supply) pictured at the top is not operating quite right. I think it is what was called a multi-vibrator type supply or sometimes referred to as a "chopper" type. The flash tube does "flash" part of the time, but then I'm thinking the HV supply drops and the tube stops firing?? Vacuum pump was inop when I got it just like everything else was. Got the vac pump working fine now, RPM meter responds to varying speeds but isn't 100% accurate.

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Very cool! I’m electronically retarded so any two wires together scare me.

If you can get new parts that will play well with what you have it will be worth it to fix it.

I just did a video last night testing a complete ignition system. I have the tach that came with the machine and an external Auto Meter tach. The Auto Meter tach is off 100 RPM all the way up. So at a 1k idle on the tach is really 900.

You’ve got to test everything because everything is pretty much junk.
 
69DodgeMan said:
Probably, but as we know, "Rare" doesn't always translate into "Valuable".

I'm sure I paid too much for it and will never be able to recoup that expense. :(
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You may be surprised. There is still a big market for correcting timing curves and testing ignition systems.
 
yellow rose said:
You may be surprised. There is still a big market for correcting timing curves and testing ignition systems.
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Totally agree with you. Get calls all the time, but I only do Mopar's, way to many parts to have on hand.
 
Something else there is definitely a market for.
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chryslerfat said:
I pulled the trigger and got one tonight. It spins when turned on but sounds like it needs bearings. The gauges are non working, He said when he turned it on the red lead was on the post and started smoking so now it has no power at that clamp. Hopefully one day I will find time to try and fix it.
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Murray said:
Remember that is distributor RPM not engine RPM. Distributor is 1/2 of engine.
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chryslerfat said:
I pulled the trigger and got one tonight. It spins when turned on but sounds like it needs bearings. The gauges are non working, He said when he turned it on the red lead was on the post and started smoking so now it has no power at that clamp. Hopefully one day I will find time to try and fix it.
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25 years ago I had a gent offer me a Sun distributor machine for free " just to get rid of it" At the time I was to dumb to take him up on his offer.
Hind site is 20/20
 
Posted 11 November 2017 - 02:00 PM

I don't know why but that just reminded me of my autoshop teacher and his antics. Mr. Birmingham, we called him 'Aunt B'.

What a great guy, good teacher.


Reminded me of how he would randomly connect and power up the Sun Distributor machine coil to the door knob after the bell would ring. If you got there late and grabbed that knob back down the hall you went. Oh yeah... I remember that well.


If he saw you smoking in the shop or out back he would take a bucket full of nasty water from the tire leak checking well, sneak up and yell 'fire' and throw that nastyass rusty water on us.


He drove a Land Rover to school daily and said he had a 70 LT1 Vette at home. As a senior he had 3 of us up to his rural house once, gave us beer, showed us his Vette and told many tall street racing tails. he was always 'teaching' us.

I remember standing in the door of that rickety old detached one car garage gaga over that car and he told us "garage floors are mostly level, always leave the car in neutral with the brake off. This way if you have a fire you can push or pull the car out and save it." IIRC he told us he learned that one the hard way.

He was a teacher but he was a Punk.

A really good teacher like that would be in jail today ...



Headline reads:


"Teacher Shocks Students With 10,000 Volts For Being Late To Class"
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sounds like pranks my cousin-in-law would pull on his students...though I think the majority of his were vocal. Teachers like that were fun to learn from.
 
69DodgeMan said:
I don't think it is too terribly different than the later models. It is direct drive instead of a belt drive. The wiring is probably a little more "primitive" but I'll bet the basic concept of operation is very similar. I've a feeling that the power supply (I think its a high voltage supply) pictured at the top is not operating quite right. I think it is what was called a multi-vibrator type supply or sometimes referred to as a "chopper" type. The flash tube does "flash" part of the time, but then I'm thinking the HV supply drops and the tube stops firing?? Vacuum pump was inop when I got it just like everything else was. Got the vac pump working fine now, RPM meter responds to varying speeds but isn't 100% accurate.

View attachment 1715539229 View attachment 1715539230 View attachment 1715539231
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I had missed this. I don't know about Sun machines specifically, but the HV supply is commonly called a "vibrator" power supply. This makes "fake" ac by chopping DC. It works sort of like a buzzer with extra contacts. Two major types. One chops DC and feeds it through a transformer to step up/ down the voltage to desired level, then separate rectifier tube(s)/ selenium/ diodes rectify back to DC

The second type is called "synchronus". Again, the vibrator chops the dc, feeds it through the transformer, now the transformer goes back to separate contacts on the vibrator which now acts as a rectifier to "pick" the proper phase of the chopped signal and send that out as pulsating DC, to be filtered by a capacitor.

Hard to say what is wrong. Vibrators certainly went bad. If you don't care about internal "restore correct" you can buy various solid state inverter/ chopper/ switch mode/ "switching" supplies on egag. If you want to fix that one, start by looking for, and replacing, a filter cap maybe under the chassis. The "good news" is that at least one cap, pictured is an oil filled (rectangular can with ceramic insulators) and these almost never fail unless they leak. THAT is a problem with type of oil, as it can be a carcinogen
 
rustycowll69 said:
at least with a Sun, there's a good chance you can get parts, & literature for it. There are( or at least WERE) companies that rebuild them.
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Mark at Paramount is the go to guy on them. He restores them and sells most parts and books needed also. I deal with him all the time. I have to keep my machines running obviously.
 
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