[aprssig] OffTopic...

Mike Yetsko myetsko at insydesw.com
Mon Aug 30 18:02:26 EDT 2004

But since the knowledge base here...

Anyway, the car I have my radio gear in developed a problem.

It's an intermittent (not so intermittent on cool mornings after a damp
miss.  I get no error codes on the diags.  So I thought plugs...  Not the
plugs.  So now I'm chasing electronics.


Years ago, in one of the electronics hobiest magazines, I saw an article
interfacing a scope to your car motor.  You made a small adapter and tied
it to the main coil line.  (HV actually.  It reduced it a lot!)   Then you
a second interface and tied it to the spark plug for the number 1
By setting the trigger and time base correctly, you could see all the
and get an idea of what the high voltage is doing.  Was a really neat diag
tool for my 68 Mustang!

But...  Those were the years of Dumont 701 Cathode Ray Oscillographs.
Cheap at worst, and tube inputs.  Also, ignition voltages were probably
to an order of magnitude less than they are today.

Since the only scope I have is a portable digital storage scope and I
want to trash it trying to hook to my Dodge, anyone have any
on how to couple to the high voltage to look-see what's going on?

I figure it can't be that much more difficult than looking at the output
of some
HF linears...


More information about the aprssig mailing list