Repairing Merc-O-Tronic Model 98 - Ignition Anaylzer

Thread Starter

Anna Swinemar

Joined Oct 31, 2017
29
I have two Merco-o-tronics Model 98 and both are unable to do a proper coil power test. There are a few bad parts in each (bad POTS, capacitors, wires need replaced). Both have a Merc 1960 406593. I've attached a pic. I'm not completely sure what it is. My guess is a capacitor. They both seem bad to me. If you shake one of them there are a couple small pieces rattling around inside. I believe these "caps" are used to charge up the coils to be tested.

Does anyone have any experience with these units? If so, has anyone had any luck finding replacement parts or equivalents?

Fixing these for a friend who owns a business and says these testers are priceless to him and his business.

PS I have the original manual.

Thanks in advance!
 

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debe

Joined Sep 21, 2010
1,389
When mine stoped working & was rattling inside, I found part of the reed armature had fallen off. I just soldered it on & is still working.MERCO 9800 Vibrator.2.JPG MERCO 9800 Vibrator.12.JPG
 

LesJones

Joined Jan 8, 2017
4,174
I thought it looked like a vibrator. I remember them from when I was a kid. There was lots of WW2 surplus about and these were used to convert DC to AC so it could be stepped up via a transformer and rectifies to provide the high voltage for valves. An electronic version could be made now. There was also lots of motor generators around at the time that were also used to supply high voltage for valves. (Tubes for people in the US)

Les.
 

Reloadron

Joined Jan 15, 2015
7,480
I thought it looked like a vibrator. I remember them from when I was a kid. There was lots of WW2 surplus about and these were used to convert DC to AC so it could be stepped up via a transformer and rectifies to provide the high voltage for valves. An electronic version could be made now. There was also lots of motor generators around at the time that were also used to supply high voltage for valves. (Tubes for people in the US)

Les.
Tube type (or valve type) car radios also. Turn on the radio and you could hear the hum of the vibrator as the tubes (valves) warmed up. Les, I am pretty sure we just dated ourselves. :)

Ron
 

Dodgydave

Joined Jun 22, 2012
11,277
I yes i remember the valve radio oscillator , just a relay pulsing a coil at it's own resonance...

You can recreate this with a 555 timer or using a wash wipe delay relay, just alter the delay time..
 

debe

Joined Sep 21, 2010
1,389
This is the wave form with freq driving an ignition coil. I have considered using a NE555 & Ignition switching transistor to replace the vibrator, as the vibrator gets quite warm driving a coil at 1.5 amps. MERCOTRONIC. IGN COIL..JPG
 
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