HMV 102 plays some records and not others.

[mikeverrechia]

Hi. I have found that my HMV 102 will play some records fine, but struggles, and runs very slow with others.

I will try giving the very slow ones a good cleaning but wondered if this is normal, or is it a sign of a weak spring?

I bought a new spring but didn't install it as it is 15ft 6ins (4.7m) long. I repaired the original spring which was broken at its outer end. I managed to do the repair in the annealed part of the end. The original spring is 13ft 4ins (4m) long.

Does anyone know what the correct length of the spring should be please?

Many thanks.....Mike

[epigramophone]

According to my 1954 Vulcan mainspring list, the spring in the HMV270 Series motor fitted to the 102 is 14 Feet long.

A badly worn record will increase the drag on the needle and expose a weak spring. For that reason I always take a badly worn record and some loud tone needles with me when examining a gramophone with a view to purchase.

[mikeverrechia]

OK. Many thanks for your reply.

I have a spring which was supplied as new, but I was told it is too long at 15 ft 6 ins. Your information suggests it is 1 ft 6 ins too long.

Given the original spring seems weak, I'll try shortening the new one. Have you ever tried this? I'm able to make the key-hole end, where it fastens to the outer part of the spring case, I'm not 100% sure about the heat treatment (annealing or tempering). I think tempering makes metal less brittle after hardening.

If you know about this, I would be grateful for advice. I have a friend with a gas torch.

Thanks again......Mike

[epigramophone]

I never learned to work on springs because I had the late Philip Knighton (The Gramophone Man of Wellington, Somerset) half an hour's driving away.
I understand from a plumber friend that annealing makes metal more workable. Good luck!

[emgcr]

You may find this video helpful ? Please take note of the first two comments under the video regarding correct nomenclature etc. Good luck.

https://www.google.com/url?sa=t&source= ... Uy1YQ31cOC

[Lah Ca]

In the interim, there are some things you can try with problem records.

Lengthen the needle by not fully inserting it or inserting it only to the point where it can be secured. This will make the rake angle more acute, which will reduce drag somewhat.

Try a lubricant with problem records. I have used Carnauba wax, and there is some historical precedent for this. Member Orchosol sells ibota wax, which seems to be highly regarded. Other members here recommend WD40.

Ibota wax: https://www.burmesecolourneedles.com/usingbcn Scroll down for video links.

For me the use of lubricants on a record is a one way trip to acoustic machine play only. Once treated a record does not come back to my modern turntables.

[mikeverrechia]

Thank you all for taking the time to reply. All comments and suggestions are really useful.

A final question.......Would you say installing the 15ft 6ins (4.7m) spring will be OK without taking its length down to 14ft? A quick estimate, using "pie" x diameter = circumference, reveals that the extra 18 inches of length only amounts to approximately one and a half revolutions of the spring at its outer edge.

I suppose I could try it but wondered what your thoughts are regarding this.

Thank you all again......Mike

[emgcr]

The longer length will produce a coil-bound situation sooner than the correct original length which will have been optimised by the manufacturer. However, who knows what this means in practical terms. Only empirical results will tell ! Try it as is and then see if you need to modify would be my thoughts.

[Orchorsol]

Before you go to the trouble of removing the spring, are you certain the governor is precisely set up? If they are set just a tiny bit tight, they can cause the problem you're experiencing.

[OrthoFan]

I agree with "Orchorsol". Along this line, is the sound box's throat gasket in good, SOFT condition? If it's hard, that will impose more back and forth resistance on the record, especially ones with slightly worn grooves. Replacing the gasket will also improve the sound quality and reduce wear. (You probably already know that it's best to use a fresh steel needle to play only one side of one record, so I won't mention that. Oops, I just did! )

One test I've always used for gauging the force of the spring is to fully wind the gramophone and then, while the turntable spins, pinch the turntable spindle with the thumb and forefinger. It should take quite a bit of force to stop it. If a relatively light pinch stops it, then the spring is probably weak.

OrthoFan