[Heathkit] Heath 4226 scope

[Edward B Richards]

 I just did that to a 3" RCA service 'scope. Quite easy, actually. I
mounted a pair of SO-239's on the back of the scope chassis and cut holes
for them to protrude through the cabinet. I disconnected the normal feed
to the plate and ran it to a switch. I connected the center pins of  the
SO-239's together for a loop-through and connected a 10  pfd capacitor in
series with a 20 pfd variable capacitor to ground to form a capacitance
voltage divider. I connected the junction of the 2 capacitors to the
switch which selects either the capacitors or the normal circuitry to go
to the vertical plate not controlled by the VERTICAL CENTERING control.
You need to do this right at the plate, after the biasing voltage is
applied to the plate. The variable capacitor sets the size of the
vertical deflection and the switch allows normal use of the scope. Run
the coax from the transmitter to one of the SO-239's and continue on from
the other. It works quite well with my Heathkit DX-100B. A simpler way if
you can dedicate a scope is just disconnect the normal feed from the
plate and run a small capacitor from the SO-239's to the plate. Adjust
the size of the capacitor to produce the size trace you want. I stole
this circuit from a Heathkit station monitor. Good luck.

73, Ed Richards K6UUZ

On Sat, 07 Aug 2004 18:42:51 -0500 Jim Isbell
<millenniumfalcon at cableone.net> writes:
> I am looking for a manual for a heath 4226 scope.  cheap, or a copy, 
> or 
> even just a few copied pages of the operations section and the 
> schematic.
> 
> I want to set it up as a modulation monitor for my HW-101.  Any 
> suggestions as to how best to do that will also be gratefully 
> accepted.
> 
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