Tracking weight issues when tonearm uses a spring

[hayerjoe]

Hello everyone

Was having a discussion on another thread about tracking weight, but started this thread as the answers may be useful to people

I'm interested to know what's the difference in tracking weight/pressure from record 1 compared to say record 6 (when 6 records are loaded on a record changer that uses a spring to set the tracking weight). I know this will be more by record number 6 but by what amount, is it tiny or quite significant. Would be good if a few people have an accurate scale and can check it out on say a BSR at record 1 and 6 so we get a good spread of results

Look forward to your findings

cheers
Joe

[hayerjoe]

OK I found a way to measure this with my own scales that I couldnt get as low as s single LP (I took the platter off, simple really, why didn't I think of it earlier?).

So on a early 60s Garrard 121 and an early 60s Philips AG1014 and a BSR 141 the difference in tracking weight from the bottom record to the 6th record was between 0.2 and 0.3g, so not very significant.

Why did I need this info? Well my scales would be measuring weight about 8mm above where a single record would be, but now with my new found knowledge it seems safe to keep measuring as I was and just subtract 0.25g if I want to be really really accurate

Hope this helps someone else out there!

[Nickthedentist]

That’s interesting, thanks.

[John10b]

Yes interesting, what was the actual tracking weight?
John

[Station X]

I wouldn't expect much difference as most of the force generated by the spring is just trying to shorten the arm, which of course it cannot do. Only a small proportion of the force pushes the stylus onto the record.

Reminds me of those old physics problems. "Where's the best place to stand when pulling a gate open with a rope"?

[hayerjoe]

Originally Posted by John10b

Yes interesting, what was the actual tracking weight?
John

The BSR was 3.82g at a single record height and 4g at the 6th record height. The phillips was half a ton and just under half a ton! (see my other 'ag1014' post today where I've got it down to just under 4g)

[John10b]

Ta, will that make any noticeable difference? What do you mean by “Ton”? Have I misunderstood?
John

[hayerjoe]

Originally Posted by John10b

Ta, will that make any noticeable difference? What do you mean by “Ton”? Have I misunderstood?
John

Sorry John, I was trying to be funny. Those Philips tonearms track quite heavily, and have no adjustment, not a ton but I think around 8g

As for the difference of 0.25g between record 1 and the 6th in a stack I don't think that is significant, but I couldnt find anywhere that had done the experiment, now it's done I don't think it's a concern when setting your tracking weight

[John10b]

Ok thanks for putting me right.
John

[Sideband]

The question is, what is right for the arm and cartridge? Some of these old cartridges were designed to track at 10g. Getting it lighter is not necessarily better although it might seem so. More damage can be done by a stylus not sitting in the groove correctly because it's too light and of course certain records might be so heavily modulated as to throw the stylus out altogether....jumping. If the arm pivot is designed such that it will follow the groove well at 10g it might not at 4g and stick. It's a question of how 'free' the pivot is.

An old deck like the Philips will probably have been designed to track at 8 - 10g....perfectly OK for the sort of use it was expected to have.

[hayerjoe]

Originally Posted by Sideband

The question is, what is right for the arm and cartridge? Some of these old cartridges were designed to track at 10g. Getting it lighter is not necessarily better although it might seem so. More damage can be done by a stylus not sitting in the groove correctly because it's too light and of course certain records might be so heavily modulated as to throw the stylus out altogether....jumping. If the arm pivot is designed such that it will follow the groove well at 10g it might not at 4g and stick. It's a question of how 'free' the pivot is.

An old deck like the Philips will probably have been designed to track at 8 - 10g....perfectly OK for the sort of use it was expected to have.

I agree with all that you say, but perhaps you missed my earlier post where I said I am fitting a modern cartridge as the old philips is dying and it's hard to find a like replacement (my headshell has the female fitting unlike virtually every other phillips which use a male plug-in head) , and I don't think there's any modern ceramic cart that likes much above 4g.

I don't mind heavy tracking but 8+g is a bit too much for my liking, but credit to Philips for their engineering as the arm, pivot and under deck mech is designed for 8+g but tracks without any skipping or audible issues as low as 4g when balanced, quite a bit beyond their design parameters I bet!

[Sideband]

Lets have some pictures of the arm and new cartridge. I always wonder how people manage to keep these Philips decks working when there is nothing on the market that even resembles the old style Philips cartridge. I imagine that you have to dismantle the old cartridge and somehow shoehorn a new one into the shell?

[wd40addict]

https://www.vintage-radio.net/forum/...d.php?t=177483

[hayerjoe]

Originally Posted by Sideband

Lets have some pictures of the arm and new cartridge. I always wonder how people manage to keep these Philips decks working when there is nothing on the market that even resembles the old style Philips cartridge. I imagine that you have to dismantle the old cartridge and somehow shoehorn a new one into the shell?

Done - see attached. Uses cheap Chinese CZ800 clone and cheap Chinese BSR clone with flip-under, both mounted on 3D printed clips, initially blu-tac'd into the original Philips headshell and when the geometry has been fully set then without moving it again hot-glued into place