[Johnson] Fw: GB> E.F. Johnson VIKING II 'C-C' Transmitter

[Eddy Swynar]

 Hi Jim Bowman,

 I'm forwarding you---and the rest of the group---a copy of Jim's (N2EY)
note to me re. the desirability of separate primary-side fusing for the
different power transformers in the Viking !!...

Jim (N2EY) I hope you don't mind my doing this, but several other fellows
besides Jim B. had asked me about some of the different ideas that were
submitted to me on the "C-C"---I think yours is especially important, & is
NOT limited to the VII alone...

Thanks again to all on the list for patience & understanding! I certainly am
happy to have come across this Reflecor!

 ~73~ Eddy VE3CUI - VE3XZ




> ----- Original Message -----
> From: <N2EY@aol.com>
> To: <gswynar@durham.net>
> Sent: Friday, March 28, 2003 8:35 PM
> Subject: Re: GB> E.F. Johnson VIKING II 'C-C' Transmitter
>
>
> > In a message dated 3/28/03 4:44:07 PM Eastern Standard Time,
> > gswynar@durham.net writes:
> >
> > > Hi Jim,
> >
> > Hello Eddy,
> > >
> > >  Well to-day I unsoldered the mod transformer & patched-in a
> replacement---
> > >  same problem. Guess I'm gonna have to start the tiresome job of
> > >  voltage/resistance measurements at each tube pin in the audio
> section...
> > >
> > That's a good problem though. RCs are easier to get than mod iron.
> >
> > I once owned an Adventurer that was built twice. When I first got it, it
> > worked so-so, but had some annoying problems and the wiring job was
awful.
> > Rather than troubleshoot, I simply took it apart, cleaned all the parts
> and
> > replaced anything that didn't test 100% or looked cruddy. Then I rebuilt
> it
> > by the book and it worked perfectly. You might consider redoing the
audio
> > section that way.
> >
> > >  BTW, the audio driver xformer in the rig is NOT original, but a Fred
> > >  Hammond replacement---so you're right, that seems to have been
somewhat
> of
> > >  an Achille's heel with these rigs!
> >
> > Hammond makes really good iron.
> >
> > I heard somewhere that EFJ mostly used iron made by SNC, and that they
> were a
> > weak spot even though they looked good. To make matters worse, some of
the
> > most hard-working iron (like the LV power trans in the V2) is custom
> stuff,
> > with special filament windings and bias taps, so you can't just drop a
> > catalog Stancor in there. I once ran my V2 with a TV power trans for the
> LV,
> > and some extra filament transformers mounted on brackets atop the TV
> trans.
> > Ugly but it worked.  Then I found a like-new V2 LV power trans at a
> hamfest
> > for $1.
> > >
> > The bleeder/slider is a weak spot, too. Replaced mine with a string of
> fixed
> > wirewounds and a wirewound pot.
> >
> > >  I still love it, though, despite this present hardship---I guess it's
> > >  called "bonding" with your radio! Hi Hi
> > >
> > I was really sad to part with my 122/Viking2/NC-173 AM setup, but I
needed
> > the money and the room. I had that V2 for almost 20 years, and it was
all
> > fixed up when I sold it.
> >
> > OOOOH! BEFORE I FORGET!
> >
> > Please do the following mod to your V2 ASAP: Add separate fuse holders
for
> > the LV and HV power transformers.
> >
> > The V2 and many other BAs use multiple power transformers, but only one
> fuse.
> > This means the fuse must be sized big enough not to blow under absolute
> max
> > load, such as the rig running full tilt on AM. Most of the power is
going
> to
> > the big plate transformer under those conditions.
> >
> > Trouble is, if there's an overload on the LV power trans (such as a
> shorted
> > filter cap or 5V4G), the big fuse won't blow until the LV power trans is
> > thoroughly cooked. Separate fuses may save a precious transformer. I
> learned
> > this the hard way.
> >
> > Some folks solid-state the supplies, and others remove them completely
and
> > use an external supply so the V2 is lighter and there's more room for
mods
> > like a compressor, splatter filter, etc. But that approach is a last
> resort
> > to me.
> >
> > 73 es GL de Jim, N2EY
>