MODEL T TIPS

7197 Mississippi Street, Merrilluille, Indiana 46410.

Some of your readers are undoubtedly using Model ‘T’
Ford coils for their gas engines. The intent of the table below is
to show voltage and FREQUENCY change with Ford magneto speed.

You will note that the frequency is independent of any deviation
in the load on the magneto, but is a direct linear function of the
revolutions per minute of the magneto.

This leads up to statement that the impedance of the ‘T’
coil is increased as the frequency increases. This is quite
necessary because if the frequency stayed low, while the voltage
rose, the coil would be subjected to over-current with possible
burn-out or at least shortened vibrating contact life. Now; if you
put pure D.C. into the coil it means that a lower voltage may be
used.

This was taken into account by Henry’s

excellent engineers as evidenced by the fact that they designed
it to operate on a 6-volt battery when not switched onto the
magneto.

The criterion for proper voltage is to see that 1.2 to 1.4
amperes were flowing while the coil is buzzing.

A more practical test was to adjust so that the high voltage
spark would jump ?’ in free air.

Operation of the coil with no external jump path is in itself a
gamble and using a voltage higher than necessary can cause internal
shorting and possible subsequent failure. Incident to the foregoing
statement, I might say that I know many of your readers have healed
an internal high voltage winding short by simply warming the coil
sufficiently to cause the insulating compound to ooze back into the
rupture.

In closing, I want to thank all the people who take enough time
to tell about their interest in this great hobby we share in
common.

Pictured is a photo of me and my ‘Separator’ tiller. I
call it this because it is the kind of machine that will separate
the men from the boys.

It was given to me as junk and I was mainly interested in the
magneto but it ran so well that I used it in my garden this
spring.

It is a very old Simar, type C2J which has a two-cycle engine
made in Switzerland. It does a really fine job of tilling, much
deeper and better than the new type tillers. The only thing you
have to look out for is hard ground because when it hits that, it
takes off like a scared rabbit.

Courtesy of William H. Payne, 111 Pratt Street, Madison, North
Carolina 27025.