Mike,

I had a Viking 2 for several years and a Challenger for a while when I 
was in college.  Later got a Viking ranger.  I can't remember if I ever 
ran the challenger on phone, used it pretty much on cw.  It was a 
crystal controlled transmitter and I didn't have a vfo for it.

I know those vikings could cause problems if you got the grid drive too 
high, but mine always seemed to level out at about max power and I just 
backed the drive down a little and tweaked the final plate a bit.  But, 
maybe I was just lucky though.  <smile>

I did this with all 3 vikings I owned but have to admit I really didn't 
mind when I later got the drace series.  Had the r4/tx4 rigs, and at one 
time or another had the a b and c.  The c was really a great radio, 
especially the receiver.

In the days of the Vikings I used an sx71 receiver.  the way that thing 
drifted, you would have thought it had an autoscan feature built into 
it.  40 meters wasn't too bad, but on any band above that you had to 
keep transmissions short otherwise you had to do some serious receiver 
tuning when you turned it over to the other guy.

It was lots of fun though.

Don  w6smb




On 1/25/2010 8:04 PM, Mike Duke, K5XU wrote:
> Most of the heath kits, including the DX60 had a drive adjustment that
> was critical.
>
> You had a capacitor to peak, then you adjusted the drive for a
> particular current value with a pot.
>
> Same goes for the DX100, Viking 2, Valiant, etc.
>
> The 6146 is a tough tube, but it has a fragile grid, so a little too
> much drive, and you buy a new final. I've been there and done that.
>
> I had forgotten how simple the T60, and its clone the HT40 were to
> tune.
>
> Johnson made another interesting transmitter called the Viking
> Challenger. I never operated one, so I'm not sure about the tuning. It
> used a low level clamp tube modulation scheme, and a pair of 6DQ5
> tubes in the final. Some people have modified them for screen
> modulation, and made them sound quite good with about 25 watts of
> carrier out on AM.
>
> I'd love to find an AM transmitter that tunes like the old Heath HW 12
> series. The grid drive was set internally, the loading capacitor was
> fixed, and all you had to adjust was the plate capacitor of the final
> for highest output, aka highest pitch.
>
> I'm resurrecting a Gonset G76. I've had it on the air, but it's got to
> go back to my friend for a little more modulation cleanup.
>
> I have an old Science for the Blind comparitor oscillator on the
> meter, but can tune it as Kevin described by using the TW1.
>
> When I get it running right, I should have about 40 watts of carrier
> output on AM.
>
> The Gonset G76 is a single 6DQ5 plate modulated by a pair of the same
> tubes.
>
> It's a transmitter, and a duel conversion receiver in the same box.
> The coverage is claimed to be 80 through 6 meters, but nobody I know
> has ever gotten a G76 to do anything other than blow up on 6 meters.
>
> It's a neat old rig, about the size of a DX60, but uses an external
> power supply.
>
>
> Mike Duke, K5XU
> American Council of Blind Radio Amateurs
>
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