|[AMRadio] Viking Ranger problem-problem fixed|
rsauvan at beyondbb.com
Sat Jan 4 20:24:09 EST 2014
I believe I have found the problem with my Ranger keying itself. I gotta
thank Jim W4ENE for providing the schematics with voltages and his
expertise on troubleshooting my problem. He hit the nail right on the
head with cap C86 being the culprit. It was sporadic but I finally just
replaced it and problem solved. My voltages were way off of the specs he
had provided but now everything seems to be right on track. I also had a
lot of help from Barry AA4EV who just lives a block away and has the
test equipment to get things figured out. Many thanks to all for their
suggesations and in particular Jim W4ENE.
On 12/31/2013 11:01 AM, Jim Tonne wrote:
> 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
> 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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