desperately seeking JVC Videosphere tuner (I know, ha-ha-ha!)

desperately seeking JVC Videosphere tuner (I know, ha-ha-ha!)

Post by Phil Nelso » Thu, 08 Nov 2001 15:44:28



Here's the deal. For the last few years I have been using a mostly-working
white JVC Videosphere as my shop TV. If it worked better I would have
promoted it, but some channels didn't come in well even after bathing the
tuner in oceans of DeOxit. I figured a competent solid-state TV repair guy
(NOT me) could put it right. Meanwhile, I viewed the good channels during
primetime and listened to a lot of NPR and shortwave at other times, which
is better for the soul in any case.

Then I get mail from a guy who used to repair Videospheres for JVC, asking
if I knew where he might find one for old time's sake. "What luck!" I
replied, "I actually have three (white, black, and red). One of them (white)
mostly works, the black one has a bright raster but nothing else, and the
red one is dead. If you agree to fix the mostly-working white one and return
it, I will give you the not-quite-working black one as your fee."

So I shipped off the white and black Videospheres, and it turns out that
both have bad tuners. In the grand tradition of throwaway solid-state
technology, these tuners are not repairable through ordinary shop
techniques. Imagine a thin film of metal (i.e., tuner contacts) over flimsy
phenolic. Then think cost-saving. In the days when this guy repaired
Videospheres, I guess the standard remedy for an iffy tuner was to yank the
old one, pitch it in the garbage, and install a shiny new one.

Not surprisingly, the shiny NOS factory tuners are long gone, so if anyone
happens to have a good (you know what I mean) Videosphere tuner, or ideally
two -- no make that three -- kicking around the shop, I'd love to make a
deal with you.

And now that everyone in the NG has finished snorting cocoa through his nose
and catapulting out of his chair with laughter, I'd appreciate any other
sources or ideas, as well. My plan of last resort is to ask this guy to make
sure this set receives channel 3 (hot-wiring if necessary), align channel 3,
and make sure the fine tuner works. Then I could play it by tuning it in
with a thrift-store VCR for ever after.

(Yeah, I could ship him the red DOA set on the off chance that its tuner
might be better than the one in my white set, but the odds for that don't
look good. And I'd rather preserve that one set intact for now, whether not
it works.)

Thanks!

Phil

 
 
 

desperately seeking JVC Videosphere tuner (I know, ha-ha-ha!)

Post by Ken » Fri, 09 Nov 2001 01:12:39


Phil
What you might do is look into finding other jvc tvs of that era & see
if they have the same tuner . i dont know where to go looking for small
jvc tv sets but its an option .

What exactly is wrong with the tuners ? in my early days of repairing &
selling small b&w tv sets including those round jvc`s i fixed many
tuners . the odd transistors may be hard to get now ?  

 
 
 

desperately seeking JVC Videosphere tuner (I know, ha-ha-ha!)

Post by John Ston » Fri, 09 Nov 2001 02:50:45




Quote:
> Phil
> What you might do is look into finding other jvc tvs of that era & see
> if they have the same tuner . i dont know where to go looking for small
> jvc tv sets but its an option .

> What exactly is wrong with the tuners ? in my early days of repairing &
> selling small b&w tv sets including those round jvc`s i fixed many
> tuners . the odd transistors may be hard to get now ?

My experience is that the contacts go intermittent and cleaning them doesn't
help.
 
 
 

desperately seeking JVC Videosphere tuner (I know, ha-ha-ha!)

Post by Phil Nelso » Fri, 09 Nov 2001 06:14:58



Quote:


> My experience is that the contacts go intermittent and cleaning them
doesn't
> help.

Yup, that's it. Below is the tech's description of the condition.

----------
the contact wafers in both
tuners are worn badly, in some areas worn through the pad. That
condition I can't really do anything about.
Normally these tuners of this time used contacts on tuning wafers. This
one uses the printed circuit material as the contact. Repeat rotation of
the tuner over time has worn the material off the boards in areas where
the contact arm touches the board. I'm looking into possible ways to fix
the board areas the can be reached without a complete dismantling of the
tuner. To get to all of it would require pulling it completely
apart...and this is not a tuner that was meant to be serviced
----------

 
 
 

desperately seeking JVC Videosphere tuner (I know, ha-ha-ha!)

Post by Phil Nelso » Fri, 09 Nov 2001 06:17:45



The model number of the tuner is VAK-06US, in case anyone has a box of parts
lying around.

Phil

 
 
 

desperately seeking JVC Videosphere tuner (I know, ha-ha-ha!)

Post by Robert Case » Fri, 09 Nov 2001 06:34:52


Quote:



> > Phil
> > What you might do is look into finding other jvc tvs of that era & see
> > if they have the same tuner . i dont know where to go looking for small
> > jvc tv sets but its an option .

> > What exactly is wrong with the tuners ? in my early days of repairing &
> > selling small b&w tv sets including those round jvc`s i fixed many
> > tuners . the odd transistors may be hard to get now ?

> My experience is that the contacts go intermittent and cleaning them doesn't
> help.

Is there any methods of say gold plating the contacts?  Been a long
time since I had Chem 101 (and I got a C), but what I'm thinking
of is using a conductive swab dipped in some gold solution and
connecting the contact to be plated and the swab to a source of
DC current.  This even possible or feasible?
 
 
 

desperately seeking JVC Videosphere tuner (I know, ha-ha-ha!)

Post by Andy Cuff » Fri, 09 Nov 2001 06:52:42


Quote:



> The model number of the tuner is VAK-06US, in case anyone has a box of parts
> lying around.

> Phil

Have you thought about installing a tuner from another TV?  Most tuners
are similar enough so that you could probably get something that would
work if you can find something that will physically fit in the TV.
--
Andy Cuffe

 
 
 

desperately seeking JVC Videosphere tuner (I know, ha-ha-ha!)

Post by jim mennin » Fri, 09 Nov 2001 07:56:09



"I actually have three (white, black, and red).

FYI---For the JVC Videospheres:

White sets are common

Red sets are harder to find

Black ones are scarce

If you ever have a choice:   keep the Black one!!!(or sell it to me)

Also, the sets with the clock in the base are rarer than the plain style
base sets.

Jim Menning

Collector of Itsy, Bitsy, ***y, Weeny, Tiny, Little TVs and Radios
Buyer of Small LCD and CRT TVs-The more unusual, the better!

 
 
 

desperately seeking JVC Videosphere tuner (I know, ha-ha-ha!)

Post by Phil Nelso » Fri, 09 Nov 2001 08:37:04


Well, I bartered the black one away in hopes of getting the white one fixed
properly. Both have bad tuners, as it turns out. Of the three that I had,
only the white one had the clock base, another reason (apart from it kind-of
working) to keep it. Scarce or not, and working or not, the red one looks so
cool that I couldn't bear to part with it. Assuming my white set comes back
in one piece, I suppose I can always tune it permanently to channel 3 (at
least THAT contact shouldn't be worn out) and tune through an old VCR as I
do with a couple of other old TVs to save wear on their tuners. Given the
throwaway design, it sounds like that would be a good idea even if the tuner
were working fine.

Phil


Quote:



> "I actually have three (white, black, and red).

> FYI---For the JVC Videospheres:

> White sets are common

> Red sets are harder to find

> Black ones are scarce

> If you ever have a choice:   keep the Black one!!!(or sell it to me)

> Also, the sets with the clock in the base are rarer than the plain style
> base sets.

> Jim Menning

> Collector of Itsy, Bitsy, ***y, Weeny, Tiny, Little TVs and Radios
> Buyer of Small LCD and CRT TVs-The more unusual, the better!

 
 
 

desperately seeking JVC Videosphere tuner (I know, ha-ha-ha!)

Post by Jeffrey D Angu » Fri, 09 Nov 2001 09:19:27


Well, just a random thought. And obivously a highly labor intensive one.
I remember using a product (20 years ago) called "circuit Stick"
Basically, a roll of copper in varying widths with adhesive backing.
Sort of do it yourself PC boards with out the "hassle" of photography
and etching.
I guess it depends on just how badly you want the JVC to work.

Jeff

Quote:

>----------
>the contact wafers in both
>tuners are worn badly, in some areas worn through the pad. That
>condition I can't really do anything about.
>Normally these tuners of this time used contacts on tuning wafers. This
>one uses the printed circuit material as the contact. Repeat rotation of
>the tuner over time has worn the material off the boards in areas where
>the contact arm touches the board. I'm looking into possible ways to fix
>the board areas the can be reached without a complete dismantling of the
>tuner. To get to all of it would require pulling it completely
>apart...and this is not a tuner that was meant to be serviced
>----------

 
 
 

desperately seeking JVC Videosphere tuner (I know, ha-ha-ha!)

Post by Ken » Fri, 09 Nov 2001 10:12:43


I would go the rout with the thin copper stuff cut pieces to match whats
in the tuner and with a heat regulated soldering station solder new
contact pads over the old ones . I have not seen inside one of those
tuners in 15 years or more so i cant say its possible but with patience
i bet it could be done .

ken  

 
 
 

desperately seeking JVC Videosphere tuner (I know, ha-ha-ha!)

Post by Scott W. Harv » Fri, 09 Nov 2001 15:47:07


It can.... I have done it. It requires complete dismantling of the
tuner, though......Not an operation for the squeamish. I would set
aside at least 3 or 4 evenings to do it. I used the really thick
copper tape, cut into the appropriate shapes.

IIRC, JVC used a continuously variable tuner on the very late models
of this set to eliminate this problem.....I'll bet they had tons of
complaints; the original tuner is really chessy.

Whatever you do, do NOT hotwire the tuner..... an easier and less
invasive solution would be to add audio and video jacks by using RCA
patch cords tied to the appropriate points after the respective
detectors,*** discreetly out the back of the set-no drilling
required.

-Scott



Quote:
>I would go the rout with the thin copper stuff cut pieces to match whats
>in the tuner and with a heat regulated soldering station solder new
>contact pads over the old ones . I have not seen inside one of those
>tuners in 15 years or more so i cant say its possible but with patience
>i bet it could be done .

>ken  

 
 
 

desperately seeking JVC Videosphere tuner (I know, ha-ha-ha!)

Post by Phil's Old Radi » Sat, 10 Nov 2001 05:15:02


A useful idea, but the "physically fit" part is problematic. This is the
round "space helmet" model and the tuner is cramped into the top of the
sphere at a slant. The replacement would have to fit very exactly!

Phil


Quote:
> Have you thought about installing a tuner from another TV?  Most tuners
> are similar enough so that you could probably get something that would
> work if you can find something that will physically fit in the TV.
> --
> Andy Cuffe