[Boatanchors] Thoughts on the Viking Mobile Xmtr.

[Carl]

"40M  you understand was a new band in 1953... so building in 40m 
capability
was Optional !"

Since when? Or did you have a brain fart and mean 15M which became 
available in May 1952?

Carl




----- Original Message ----- 
From: "BLIMPY" <blimpboy at sonic.net>
To: <k7vnw at charter.net>
Cc: <boatanchors at mailman.qth.net>
Sent: Wednesday, December 03, 2008 4:29 PM
Subject: [Boatanchors] Thoughts on the Viking Mobile Xmtr.


>
> The viking mobile is a real mixed bag.
>
> The recapping is a cinch... very few to do and they are easy to get 
> at.
>
> Making power cables wouldnt be hard... except that everything to do 
> with the manuals is a treasure hunt.
>
> There is an assembly manual and there is an operation manual... each 
> has some info and omits other stuff.
>
> Since they tried to accomodate an huge range of altermative power 
> supply combinations and installations.. they managed to make it 
> infinitely complex.
> Also,  some of the assumed conventions of the time ( early 50's)... 
> like using a recieving converter with a vibrator supply, and feeding a 
> very Low Z mobile whip
> ( maybe 5 to 15 ohms on 75 m)  make this even more difficult when you 
> want to set the thing up to work on AC at home.
>
> Now, some or all of that comes with most mobile rigs for the early 
> 50's  - so I am getting used to it.
>
> But,  there are uniquely Viking Mobile problems to conquer.
> Some of them electronic....  a very detailed set of steps one must 
> follow to get the ganged tuning of osc, driver and final all to track 
> on each band...
> which can require the winding and installation of supplemental osc and 
> driver coils on 75, and 40, if tap selection won't work  on those 
> bands, as built.
>
> 40M  you understand was a new band in 1953... so building in 40m 
> capability was Optional !
>
> This  band by band tracking adjustment is all sufficiently tedious 
> that I think whoever built the rig.. got it going on 10 M and called 
> it good !
>
> The other potential issue is that each stage  working back from the 
> front panel... osc, driver, and final  is physically separated by a 
> vertical aluminum plate the entire width and height of the radio. 
> Strategically buried in the middle of each plate are the band switch 
> wafers for that stage.   Should some poor fool such as myself wish to 
> inspect those wafer switches.. say to clean them after 55 years, or 
> to see if the builder had made a mistake, or to find a fried wafer... 
> it's Rotsa Ruck
> unless you fancy some major dissasembly - perhaps for nothing.
>
> Things I normally would do... like using a rubber eraser pencil to 
> physically clean wafer switch wipers... basically cannot be done 
> without damage.
>
> Somethings about the rig are so odd... that I find myself wanting to 
> talk to somebody who has used / worked on one of the things 
> extensively.
> Not easy to do.   I think of this as one of the rigs you are least 
> likely to ever hear on the air. Like a Cosmophone.
>
> I  am encouraged that the thing DOES work normally on 10 M.... and 
> that there IS grid drive on 20 and 75.
> That does tend to narrow things down.   So,  when I have some more 
> time to scratch my head.. and think my way through the thing logically 
> again...
> I will have at it again.  Looking at 75M padding caps, and more 
> switches !
>
> Sometimes letting these things percolate in the back of your mind 
> yields a break through to the obvious.
>
> What bugs me is normally I have no trouble fixing even obscure faults 
> in transmitters and recievers.
>
> Larry
> _______________________________________________
>