[AMRadio] Viking Ranger problem

Jim Tonne Tonne at Comcast.Net
Tue Dec 31 13:01:27 EST 2013


A few years ago I was trying to figure out how the keying circuitry in
my old Ranger was working.   I ended up entering it into LTspice
circuit analysis program.

The way the thing works is that as soon as the key is closed the
VFO is immediately unblocked (it is normally pinched off by a large
negative voltage).    The VFO immediately comes on.

Then the multiplier and buffer stages are ramped up smoothly to
avoid key clicks.

When the key is opened the multiplier and buffer are ramped down
smoothly to avoid key clicks.   THEN after a short time delay the VFO
is turned off.

The VFO will remain on if C86 is shorted.

The multiplier and buffer stages will remain on if C89 is shorted.

The buffer will remain on if C87 is shorted but this should be a non-issue.

My money is on C86 being shorted.

A quite easily readable schematic showing all of the above has just been
posted.   See it here:


Case-sensitive, if you are entering it by hand.

Hope this helps.

- Jim Tonne   W4ENE

On 12/31/2013 8:56 AM, Robert Sauvan wrote:
> Hi all,
> Was hoping for some suggestions as to where to start looking for my 
> problem that just cropped up with my Ranger. I was in a cw qso the 
> other night and all of a sudden the transmitter decided to keep keying 
> continuously. I cant get it to stop now.
[ snip ]

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