Hi Jim,

I had the same problem ~10 years ago with mine on ititial setup.
The most immediate problem with a "good" answer is my
shrinking memory cells (ha).

I think (without delving into the parts manuel at
this time), (us guys don't read the manuel first....ha.) is that
towards the top rear is where there is a knurled round nut that
is also a wire locking compression (screwing) clamp (I think
with a setscrew underneath); that actually connects to the
zero length spring.  There was also another compression
nut further down from the top nut that needs to be loosened.
You would "overall" need to lower the wire somewhat to find
a area of the wire to clamp down on....to where.....the mass
oscillates,  and can be "zeroed" the best, per the pointer from
the boom that goes over the scale on the upright
aluminum post with the boom clamp hole.  The total wire
movement "might" only be ~ 1/2", but perhaps up to 1" or
more (?).

I'd level the base with the setscrews and a bubble level in both
directions first.  Check and see if that does the trick with the boom
unlocked.  If no success, you need to clamp the boom in place
with the locking pin in the holes provided for the front and rear
areas, so it doesn't move.  The locked boom protects about
everything from damage if the spring gets loose on one end,
which it probably can/will happen potentially.

I literally marked this upper wire near a seismo part with a felt
tip pen to show where it is at the present....you know it would
need to be alittle further down than it was, once you unclamp
the wire on the top.  Of course once you unclamp, the spring
contraction force will jerk it down very fast....you need to limit
this amount of movement with other outside wire holding clamps
locking vise wrench grips etc., means.  Keep up marking the
wire for a past position reference.  I sanded the wire to get a
clean shiny surface, to see the black marker ink.

Relock the wire, unclamp you tool clamps, unlock the boom,
and test.  You may have to do this quite a number of times, to
find a nice zeroing pointer/marker place.  Of course you need
to keep in mind that the setscrews and the seismo base also
play a part in this balance/zero.....and also the seismo period
length one sees, or wishes to have.  If....you go down too far
then it becomes a physical effort to pull on the upper wire
(many pounds of exertion), and at the same time eyeball for the
wire mark and also be ready to use the setscrew to clamp down
on the wire.  You may need a strong friend to help pull/stabilize
the wire.  It can be a pain in the maximus glutomus to do this stuff,
but it did work out in the end for me.  If the wire breaks, no big
deal; its common music wire.  Keep your fingers away from the
spring during all of this, if it gets loose, it could break/smash
fingers
that are in the way.

Whenever you move the unit, you might expect to have to do it
again.  Once its adjusted, their might be a month or two of
"settling in" waiting time, but thereafter, it usually is very
stabile...
moreso than any horizontal...but make sure it has a good
temperature stable environment if possible.  If the drift is high
after acouple months; its a strong clue/suggestion that it needs
more insulation from temperature extremes.  Its a very good
machine I think overall, and it offers a variety of potentials for
add-ons sensors actually.....if one is so inclined to try.  Its
worth the time/effort....verticals are always the most useful,
scarce (and often difficult adjustment) machines.

If I remember correctly....the manuel doesn't cover the topic,
for the time (50+ years ago), they wanted to send out company
techs to do the setup stuff for the original buyer.  All this effort
will acquaint you well with the machine.  I think it took me
several (grumbling, fumbling, learning) days to get it adjusted....ha.

Take care, Meredith Lamb

RADIOTEL@....... wrote:

> I have a vertical sensor like yours and the one that was recently on
> Ebay.  However, no matter how I try I can not balance it so the
> pointer stays in the center of the indicator on the front of the
> unit.  The best I have been able to manage is with the pointer near
> the top of the dial, but it does work there.  Any ideas or suggestions
> would be appreciated.
> Thanks
> Jim Allen


Hi Jim,
I had the same problem ~10 years ago with mine on ititial setup.

The most immediate problem with a "good" answer is my

shrinking memory cells (ha).
I think (without delving into the parts manuel at

this time), (us guys don't read the manuel first....ha.) is that

towards the top rear is where there is a knurled round nut that

is also a wire locking compression (screwing) clamp (I think

with a setscrew underneath); that actually connects to the

zero length spring.  There was also another compression

nut further down from the top nut that needs to be loosened.

You would "overall" need to lower the wire somewhat to find

a area of the wire to clamp down on....to where.....the mass

oscillates,  and can be "zeroed" the best, per the pointer from

the boom that goes over the scale on the upright

aluminum post with the boom clamp hole.  The total wire

movement "might" only be ~ 1/2", but perhaps up to 1" or

more (?).
I'd level the base with the setscrews and a bubble level in both

directions first.  Check and see if that does the trick with the
boom

unlocked.  If no success, you need to clamp the boom in place

with the locking pin in the holes provided for the front and rear

areas, so it doesn't move.  The locked boom protects about

everything from damage if the spring gets loose on one end,

which it probably can/will happen potentially.
I literally marked this upper wire near a seismo part with a felt

tip pen to show where it is at the present....you know it would

need to be alittle further down than it was, once you unclamp

the wire on the top.  Of course once you unclamp, the spring

contraction force will jerk it down very fast....you need to limit

this amount of movement with other outside wire holding clamps

locking vise wrench grips etc., means.  Keep up marking the

wire for a past position reference.  I sanded the wire to get
a

clean shiny surface, to see the black marker ink.
Relock the wire, unclamp you tool clamps, unlock the boom,

and test.  You may have to do this quite a number of times, to

find a nice zeroing pointer/marker place.  Of course you need

to keep in mind that the setscrews and the seismo base also

play a part in this balance/zero.....and also the seismo period

length one sees, or wishes to have.  If....you go down too far

then it becomes a physical effort to pull on the upper wire

(many pounds of exertion), and at the same time eyeball for the

wire mark and also be ready to use the setscrew to clamp down

on the wire.  You may need a strong friend to help pull/stabilize

the wire.  It can be a pain in the maximus glutomus to do this
stuff,

but it did work out in the end for me.  If the wire breaks, no
big

deal; its common music wire.  Keep your fingers away from the

spring during all of this, if it gets loose, it could break/smash fingers

that are in the way.
Whenever you move the unit, you might expect to have to do it

again.  Once its adjusted, their might be a month or two of

"settling in" waiting time, but thereafter, it usually is very stabile...

moreso than any horizontal...but make sure it has a good

temperature stable environment if possible.  If the drift is high

after acouple months; its a strong clue/suggestion that it needs

more insulation from temperature extremes.  Its a very good

machine I think overall, and it offers a variety of potentials for

add-ons sensors actually.....if one is so inclined to try.  Its

worth the time/effort....verticals are always the most useful,

scarce (and often difficult adjustment) machines.
If I remember correctly....the manuel doesn't cover the topic,

for the time (50+ years ago), they wanted to send out company

techs to do the setup stuff for the original buyer.  All this
effort

will acquaint you well with the machine.  I think it took me

several (grumbling, fumbling, learning) days to get it adjusted....ha.
Take care, Meredith Lamb
RADIOTEL@....... wrote:
I have a vertical
sensor like yours and the one that was recently on Ebay.  However,
no matter how I try I can not balance it so the pointer stays in the center
of the indicator on the front of the unit.  The best I have been able
to manage is with the pointer near the top of the dial, but it does work
there.  Any ideas or suggestions would be appreciated.

Thanks

Jim Allen