Anyone using an old stye Sun tach transmitter?

jjbubaboy
jjbubaboy Senior Contributor
edited November -1 in HUDSON
Hey,

I have a good old tach and a transmitter for 6 volt 6 cylinder I want to put on my 36 T.

The transmitter has the old mercury 1.35v battery still in it soldered to one wire. (and crusty too!)

Anyone replace one of those or using one? What can it be replaced with?

Any ideas or leads?

Thanks!

T Jeff

Comments

  • [Deleted User]
    [Deleted User]
    We run one on our '49 Coupe.



    The old mercury battery was replaced by a AA battery. Go to radio shack and get a single AA battery power supply box and fit it to the Sun Transmitter case where the old battery was. Observe the polarity of the old battery and resolder the wires from the transmitter to the new AA battery holder. We used a piece of fitted styrofoam to fit between the case and the battery to hold it in place after reassembly. Its worked fine.



    There is a voltage difference, AA batteries are 1.5 volts instead of the 1.35 of the old mercury battery. As long as we ran points/condenser, we could tune the transmitter's solenoid points with the adjustment screw and it would be accurate. The adjustment screw acts like a mini-voltage regulator by adjusting the points on the transmitter's solenoid.



    For some reason, we can't trim it in as well with the pertronix. We're not reading the true rpm anymore with the pertronix. I can adjust the transmitter screw and get it accurate within a 1000 rpm range - but it will be off everywhere else. It may be the voltage of the AA battery, being over 1.5 volts by enough that I can't fudge it with the adjustment screw.



    There is an alternative to the old electronics in the Transmitter. I think much more of my Pertronix unit than to go back to points just to have a stock Sun transmitter.

    http://www.beiautomotive.com/tachmainpage.htm



    If I keep having problems with my transmitter working with the pertronix unit, I'm going to get the new board.



    Hope that helps.



    Mark
  • jjbubaboy
    jjbubaboy Senior Contributor
    Hey Mark,

    Yes that is a huge help, thankyou!

    I am glad you mentioned about the pertronix as well since I do have plans to change mine over this winter as well.

    Will have to check out the new and improved circuit boards when that time comes!

    Thanks again,

    T Jeff
  • jjbubaboy
    jjbubaboy Senior Contributor
    Now thats a good point, Rick!



    Jeff
  • [Deleted User]
    [Deleted User]
    I've talked with the guys at BEI and Pertronix.



    Neither of them know why. Pertronix just says to get a modern tach. The BEI guys say it doesn't always happen and I should be able to tune out the difference with the solenoid points. So, it could be a weakness in my Transmitter's system - these things are getting really old. It looks like new inside, but that doesn't mean all is well.



    My problem may be associated with my individual transmitter. There is so much EMF coming out of my sun box, my timing light tach goes bananas if it gets close to it. I'm suspecting my solenoid may be going out or I'm getting too much voltage from somewhere besides the AA battery. If I were Park Waldrop, I'd have this figured out - but I'm not electronicly savvy.



    I'm thinking one of those BEI boards is in my future.



    The points in the transmitter will need adjusting if you run the AA battery, and will need another adjusting if you run Pertronix. If all is well with your transmitter - no problem. I think I may have a transmitter problem. I did not mean to lay this apparent problem at Pertronix's feet.



    Mark
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