[tack]

Greetings;
Looking for a replacement meter movement for a B&K model 707; anyone
know of a source? Thanks

[Scott Dorsey]

tack wrote:
Greetings;
Looking for a replacement meter movement for a B&K model 707; anyone
know of a source? Thanks

What is wrong with the meter? There are still folks out there that will
repair broken meter movements... the guys in rec.radio.amateur.boatanchors
can recommend one. If it's just the thing out of the socket or the jewels
popped out, though, you can probably fix it yourself with a steady hand and
a magnifier.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[tack]

someone; for reasons I cannot fathom, filled the meter with fine
powdered iron. Too much to be an accident. I mean it was FULL.
FIlled up the entire movement, nook and cranny. I tried to dig some
out of the spaces, and tried to blow some out. The magnet holds onto
the powder tight. The movement is jammed, and also the particles
penetrated into the fine D'Arsonval wire shorting it out. I do not see
how it could be repaired.
I replaced the meter with another one that I bought from someone over
the 'net that parted out a B&K tube tester; it works, but it's not the
same. The original had a scale that went from 0-120 and the replacemet
goes from 0-6000 in micromhos. Both have the same "replace" "?" and
"good" scales. Dunno, maybe the replacement is better?

Scott Dorsey wrote:
tack wrote:
Greetings;
Looking for a replacement meter movement for a B&K model 707; anyone
know of a source? Thanks

What is wrong with the meter? There are still folks out there that will
repair broken meter movements... the guys in rec.radio.amateur.boatanchors
can recommend one. If it's just the thing out of the socket or the jewels
popped out, though, you can probably fix it yourself with a steady hand and
a magnifier.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

tack wrote:
someone; for reasons I cannot fathom, filled the meter with fine
powdered iron. Too much to be an accident. I mean it was FULL.
FIlled up the entire movement, nook and cranny. I tried to dig some
out of the spaces, and tried to blow some out. The magnet holds onto
the powder tight. The movement is jammed, and also the particles
penetrated into the fine D'Arsonval wire shorting it out. I do not see
how it could be repaired.

Take Scotch tape, and fold it into a wand shape, with the sticky side
out. CAREFULLY poke it around every corner of the meter. Use a flat
and larger piece between the magnets and the coil. The sticky part of
the tape will hold the tramp metal better than the magnet.

If the coil is actually damage, it can be rewound by someone who does
meter movement repair.

I replaced the meter with another one that I bought from someone over
the 'net that parted out a B&K tube tester; it works, but it's not the
same. The original had a scale that went from 0-120 and the replacemet
goes from 0-6000 in micromhos. Both have the same "replace" "?" and
"good" scales. Dunno, maybe the replacement is better?

Do they have the same movement with the same sensitivity? If so, you
can swap the scales between them and go.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[tack]

Adhesive tape will not work. Possibly meter could be repaired by
complete disassembly and cleaning. It is jammed and will not move.
The meter had a coil with 50 ohms resistance, and a 50 ohm resistor in
series. The replacement meter has a 100 ohm coil. I tested some tubes
already and compared the results with another tester, and the
deflection appears quite accurate. I would rather the B&K tester to be
all original, though. The replacement meter is a drop-in; bolts right
up, but my old meter face would require a little bit of trimming around
the edges to fit, and I do not want to cut it. Some day maybe I might
find a replacement movement that I could drop in the old meter housing.
The meter wasn't shorted before I attempted to clean it; it read 50
ohms. But now it reads 0. The iron powder that is jamming the
movement must've penetrated the winding's enamel. But maybe the short
would go away after cleaning? It might cost more to repair it thatit's
worth? Anybody have a guess as to what it will cost to fix?


Scott Dorsey wrote:
tack wrote:
someone; for reasons I cannot fathom, filled the meter with fine
powdered iron. Too much to be an accident. I mean it was FULL.
FIlled up the entire movement, nook and cranny. I tried to dig some
out of the spaces, and tried to blow some out. The magnet holds onto
the powder tight. The movement is jammed, and also the particles
penetrated into the fine D'Arsonval wire shorting it out. I do not see
how it could be repaired.

Take Scotch tape, and fold it into a wand shape, with the sticky side
out. CAREFULLY poke it around every corner of the meter. Use a flat
and larger piece between the magnets and the coil. The sticky part of
the tape will hold the tramp metal better than the magnet.

If the coil is actually damage, it can be rewound by someone who does
meter movement repair.

I replaced the meter with another one that I bought from someone over
the 'net that parted out a B&K tube tester; it works, but it's not the
same. The original had a scale that went from 0-120 and the replacemet
goes from 0-6000 in micromhos. Both have the same "replace" "?" and
"good" scales. Dunno, maybe the replacement is better?

Do they have the same movement with the same sensitivity? If so, you
can swap the scales between them and go.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

tack wrote:
Adhesive tape will not work. Possibly meter could be repaired by
complete disassembly and cleaning. It is jammed and will not move.

Honestly, try the tape. It'll take a couple afternoons worth of careful
work to get the stuff out, but you can do it.

Complete disassembly and cleaning isn't all THAT big a deal either, if
you are careful not to damage the coil wires and you have a desk magnifier.

The meter had a coil with 50 ohms resistance, and a 50 ohm resistor in
series. The replacement meter has a 100 ohm coil. I tested some tubes
already and compared the results with another tester, and the
deflection appears quite accurate. I would rather the B&K tester to be
all original, though. The replacement meter is a drop-in; bolts right
up, but my old meter face would require a little bit of trimming around
the edges to fit, and I do not want to cut it.

Why? This is test equipment here, not some valuable collectable. It's
not even lab-grade test equipment. Just make it look nice and close it
up.

Some day maybe I might
find a replacement movement that I could drop in the old meter housing.
The meter wasn't shorted before I attempted to clean it; it read 50
ohms. But now it reads 0. The iron powder that is jamming the
movement must've penetrated the winding's enamel. But maybe the short
would go away after cleaning? It might cost more to repair it thatit's
worth? Anybody have a guess as to what it will cost to fix?

Probably more than any mutual conductance tester is worth, but ask on
rec.radio.amateur.boatanchors, or do a google search on that group because
I know a couple meter rebuilding places have been discussed there.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[tack]

This tester is in exceptional condition and treated well (except for
the simian that put in the iron powder) and belonged to my wife's
uncle, who is passed away. He used it as his service tester when he
did TV repair. His son gave me much of his father's gear. So there is
some sentimental value involved. Nevertheless, if'n it's gonna cost ah
hernerd bucks tuh fix it, then it'll stay like it is.


Scott Dorsey wrote:
tack wrote:
Adhesive tape will not work. Possibly meter could be repaired by
complete disassembly and cleaning. It is jammed and will not move.

Honestly, try the tape. It'll take a couple afternoons worth of careful
work to get the stuff out, but you can do it.

Complete disassembly and cleaning isn't all THAT big a deal either, if
you are careful not to damage the coil wires and you have a desk magnifier.

The meter had a coil with 50 ohms resistance, and a 50 ohm resistor in
series. The replacement meter has a 100 ohm coil. I tested some tubes
already and compared the results with another tester, and the
deflection appears quite accurate. I would rather the B&K tester to be
all original, though. The replacement meter is a drop-in; bolts right
up, but my old meter face would require a little bit of trimming around
the edges to fit, and I do not want to cut it.

Why? This is test equipment here, not some valuable collectable. It's
not even lab-grade test equipment. Just make it look nice and close it
up.

Some day maybe I might
find a replacement movement that I could drop in the old meter housing.
The meter wasn't shorted before I attempted to clean it; it read 50
ohms. But now it reads 0. The iron powder that is jamming the
movement must've penetrated the winding's enamel. But maybe the short
would go away after cleaning? It might cost more to repair it thatit's
worth? Anybody have a guess as to what it will cost to fix?

Probably more than any mutual conductance tester is worth, but ask on
rec.radio.amateur.boatanchors, or do a google search on that group because
I know a couple meter rebuilding places have been discussed there.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."