ckh wrote:
On Mon, 7 Mar 2005 13:23:17 UTC, "W8KZW" wrote:


The LMO is supposed to tune 500 KC - from X.0 to X.5. Mine physically stops
at X.055 ... in other words, the counterclockwise "end of travel thunk"
comes too early, and won't let me tune the bottom 55 kc of the band. The
clockwise "end of travel thunk" comes where it should. These "thunks" both
sound and feel the same .... as you would expect them to: solid and
defined, neither end like the feel / sound of a coil getting caught up
inside a tube. The tuning is smooth and unobstructed across the full range.


coil in a tube?

He is thinking of a PTO where a slug could get jammed inside the
coil form.


The LMO has a shaft with rings on it. The rings have stops that
prevent you from making too many turns. It gives you five turns of
the shaft.

Each stop engages the next ring and is, in turn, engaged by the
previous.

I can't quite visualize how that simple mechanism could be
defective.

Visualize what happens when two or more of the range limiting
disks get frozen together by gummed up grease.


Within the LMO, there is a typical worm driven capacitor. No
obvious way that can be defective either.

Although it is harder, if part of the worm gear has a block of
hardened grease in its tooth, it will jamb the mechanism before
the capacitor can turn its full range. Usually there is enough
mechanical advantage in the worm gear assy that you could over
come the block but 30 year old grease can become quite hard.


The question is, how many turns does the big plastic disk make?
Should be a little over 5. If your problem is mechanical, then it's
strictly a matter of counting the turns.

His wording was difficult, but I got the impression that the markings
on the dial are exactly correct with the received frequency. So that
would mean that there is something mechanical wrong. I would bet on
the range limiting disks being frozen solid with grease or rust.

-Chuck Harris

On Tue, 8 Mar 2005 13:22:03 UTC, Chuck Harris
wrote:


He is thinking of a PTO where a slug could get jammed inside the
coil form.


The LMO has a shaft with rings on it. The rings have stops that
prevent you from making too many turns. It gives you five turns of
the shaft.

Each stop engages the next ring and is, in turn, engaged by the
previous.

I can't quite visualize how that simple mechanism could be
defective.

Visualize what happens when two or more of the range limiting
disks get frozen together by gummed up grease.

I just spun an LMO from lock to lock, 521 kHz on the dial. How do
you get from that to his 432?

I have an LMO in my parts bin. Lemme see....

Ah-HAH!

There are 6 tabs, not 5.

Each ring is about 86 kHz.

521
434
347
260
173
86

The width of the tab must be about 14 kHz... seems too wide but
maybe.

de ah6gi/4





Within the LMO, there is a typical worm driven capacitor. No
obvious way that can be defective either.

Although it is harder, if part of the worm gear has a block of
hardened grease in its tooth, it will jamb the mechanism before
the capacitor can turn its full range. Usually there is enough
mechanical advantage in the worm gear assy that you could over
come the block but 30 year old grease can become quite hard.


The question is, how many turns does the big plastic disk make?
Should be a little over 5. If your problem is mechanical, then it's
strictly a matter of counting the turns.

His wording was difficult, but I got the impression that the markings
on the dial are exactly correct with the received frequency. So that
would mean that there is something mechanical wrong. I would bet on
the range limiting disks being frozen solid with grease or rust.

-Chuck Harris


--

ckh wrote:
On Tue, 8 Mar 2005 13:22:03 UTC, Chuck Harris
wrote:

The LMO has a shaft with rings on it. The rings have stops that
prevent you from making too many turns. It gives you five turns
of
the shaft.

Each stop engages the next ring and is, in turn, engaged by the
previous.

I can't quite visualize how that simple mechanism could be
defective.

Visualize what happens when two or more of the range limiting
disks get frozen together by gummed up grease.

I just spun an LMO from lock to lock, 521 kHz on the dial. How do
you get from that to his 432?

I have an LMO in my parts bin. Lemme see....

Ah-HAH!

There are 6 tabs, not 5.

Each ring is about 86 kHz.

521
434
347
260
173
86

The width of the tab must be about 14 kHz... seems too wide but
maybe.

If two of the rings are locked together, they will move as a unit and
reduce the travel by one turn. Your test shows that the LMO moves about
432-434 kHz in four turns.

I bet the problem is purely mechanical. Frozen ring or some such.

73 de Jim, N2EY