[AMRadio] Viking Desk Modulation


Jay Bromley jayw5jay at gmail.com
Tue Jan 15 14:24:59 EST 2008


Well that article reads kinda of bad, but I was a young guy at the time, hi. 
Barry also did an article for ER.  He recorded our conversation as we talked 
on the phone about KW1 audio, then transcribe it.  The text was mostly 
correct, but the grammer was horrible.  Hey I am just a southern boy, that 
is how we talk.  It did seem to help many KW1 owners like Uncle Ed, etc.

K7VZP, K4KYV, and WA1HLR were the ones that got me on track.  I still learn 
from them and they are the ones I go to when I get in a bind.  Like so many 
times one gets the kudos when it should go to the ones above.

Yes the audio driver was the weak link, but not much room to improve unless 
one went outboard.  A quad set of 2A3s, 6B4Gs, or a couple of 6080s might 
have been good.  I kinda like a pair of the 845s, hihi.

Todd, keep that transmitter.  I really miss mine!  It is not far from here, 
but it is really showing age now.  The last time I saw it was very dusty and 
needed a good cleaning up.  When it left here it was like brand new.  You 
don't see many like that, even back then!  It sure kept me out of trouble. 
As a young guy going to Jr. College, I spent many hours getting it cleaned 
up and air worthy.  I would talk to Woodlawn Don one night, make some 
changes to the audio during the day, and then be back on the air the 
following night asking him how it sounded.  Phoenix Bill helped me with the 
PTO and also a fast make plate relay circuit with delayed antenna relay. 
After that I kept the airwaves hot 10m through 160m back in the mid 80s.

I was in my early 20s, what a wild ride it was to locate one of those and 
then get it going.  I knew nothing, but had a few good AM mentors!  I didn't 
really know what I had until years later.  Back then it was just old junk 
and to many here thought I was just stupid for playing with old winkle 
painted rigs.  Now those same guys wish they had got that rig off of me, hi.

I am still lurking on the list and have been for a long time.  I still love 
the old AM gear and AM in general.

73 de w5jay/jay..




> On Jan 15, 2008 1:02 AM, Jay Bromley <jayw5jay at gmail.com> wrote:
>> Tom,
>> It has been a long time since I owned one, but be sure to look for the
>> obvious things like wrong regulator tube in wrong socket.  Check bias and
>> screen voltages, but use great care!  My mod iron had two taps, one would
>> make slightly more than 100%, but required more audio drive.
>
> Hey Jay, good to see you on here. I use many of your 'improvements'
> for the KW-1 on my transmitter with great success, passed along to me
> by Uncle Ed WA3PUN in the days well before the internet. Many thanks!
>
> The mod iron in early Viking KWs was the same identical iron used in
> the KW-1, and has the 12,000 P-to-P winding and....18,000? The lower
> number being the less efficient but 'more audio/more drive' winding.
> This is what I use on mine. Later models Vikings used what appears to
> be the same iron, but with much larger insulators in place of the
> original small ones. Maybe breakage was an issue?
>
> Rumor has it that the mod iron is the weak link in the KW-1 in stock
> configuration, related to the splatter filter and (to a lesser
> extent?) clipper circuits. I bypassed both in mine back in the early
> 90s, but lost the mod iron last year anyhow. More likely due to age at
> this point.
>
> Viking KW didn't use either of these circuits and supposedly didn't
> have the issues of cooked mod iron that the KW-1 did. But time takes a
> toll on the old insulation, wire or fish paper, worth keeping in mind.
>
> Two things seem to come to the surface in my dealings with the KW-1:
> the mod iron certainly can't be accused of being overbuilt and running
> it at 100% likely approaches its limits; and a quad of 6B4Gs instead
> of a pair would've worked better for driving it, especially at the
> 12,000 winding. Haven't looked inside the Viking KW for a while now,
> but I think it only runs a pair also?
>
> Skip, K7YOO has a lot of experience with these transmitters and
> related iron, maybe he'll jump in.
>
> ~ Todd,  KA1KAQ
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