Phonoland

Can anyone tell me exactly where inside the blackhead there is rubber and there is grease?

Also, one of the wires that runs into the base of the needle housing is loose. I am going to attempt to re-solder it. Wish me luck.

Thanks, James

Hi James,
I don't think I have ever been inside an "original" one of those. I have found both, "all over the place"--
Ron Rich

My "A" cart had no grease or anything else in it. It also had one of the wires to the needle holder loose. I re-soldered it with my little iron.

I took apart a "B" that had never been opened. It has clear medium viscosity grease in it. Inside the shells there is a think coat of something that looks like red-orange paint. I am thinking it is similar to Armature Paint. It flakes off as soon as you touch it and is crystalline in nature not organic like rubber.

There is some small black stuff in and around the needle holder. It could be a very small remnant of a rubber isolator. But it could also just be dust from years of records. That dust mixed with grease could lead one to conclude that it is rubber remnants. I would have to see an original non-used one to be sure. I am going to post some detailed photos in the event anyone is interested.

James

That "grease" mentioned is most likely Lanolin, a sticky substance that was used in old cartridges as a damping material.
It's got a distinctive odd smell to it.

MattTech wrote:That "grease" mentioned is most likely Lanolin, a sticky substance that was used in old cartridges as a damping material.
It's got a distinctive odd smell to it.

Matt, Is there a recommended sub for that. On the Zenith Cobras I've used silicone gel or lithium grease.

Rob/NYC

Rob-NYC wrote:

MattTech wrote:That "grease" mentioned is most likely Lanolin, a sticky substance that was used in old cartridges as a damping material.
It's got a distinctive odd smell to it.

Matt, Is there a recommended sub for that. On the Zenith Cobras I've used silicone gel or lithium grease.

Rob/NYC

Rob, I would think that a silicone gel of an appropriate viscosity would suffice as a damping "fluid".
These old crude cartridges needed some form of damping to counter-act any "ringing" or harsh response inside the cartridge cavity.

Hi Guy's
Lanolin should still be available--check the drug store. All that is is Lamb grease, which, at one time was promoted as a women's skin treatment. Since James said it looks like an insulator varnish, my guess is that it might be "Red Gylpit" ( or trademarked name "Glyptol"). This was commonly used in electronics as a insulating varnish, and/or, "screw locking" product, to at least the mid- 70's. It is still available from at least two different "makers"--I just purchased a bottle of it last year--Ron Rich

Hi All,

I have some lanolin inbound. I was going to use some Plasti-Dip in place of the Glyopl. I was thinking of masking the area to the same size as the original Glypol and spray a thin coat on it.

However,...

The only issue I have not been able to nail down is the question of is there a rubber item that surrounded the needle housing. If there was, I doubt it had anything to do with the mechanical operation of it. I think it was a seal for the grease. If that is the case, instead of spraying Plasti-Dip, I may cut a small thin felt and glue it into the shells. This will take care of both the Glypol and the rubber seal. I can cut a very small slit into it. That way the "suspension system" will not be impacted by the any home made rubber "grabbing" on the needle holding shaft. The felt will isolate it electrically and will also act as a seal all in one.

Anyone have any thoughts?

James

James,
A friend of mine who just passed away, used "wide rubber bands" in them--never watched him do it, always said I wanted to, and he always said "it's easy""--I'll call you the next one I do--" Ron Rich

James_Douglas wrote:Hi All,

I have some lanolin inbound. I was going to use some Plasti-Dip in place of the Glyopl. I was thinking of masking the area to the same size as the original Glypol and spray a thin coat on it.

However,...

The only issue I have not been able to nail down is the question of is there a rubber item that surrounded the needle housing. If there was, I doubt it had anything to do with the mechanical operation of it. I think it was a seal for the grease. If that is the case, instead of spraying Plasti-Dip, I may cut a small thin felt and glue it into the shells. This will take care of both the Glypol and the rubber seal. I can cut a very small slit into it. That way the "suspension system" will not be impacted by the any home made rubber "grabbing" on the needle holding shaft. The felt will isolate it electrically and will also act as a seal all in one.

Anyone have any thoughts?

James

Felt would likely attract dust buildup.
Tear apart a broken or unuseable remote control, and utilize the thin silicone rubber buttonpad.
Ususally there is a flat useable area of it that can be cut and used as a nice pliable seal.

Hi All,

I have found a original Pickering Patent on a magnetic cartridge c.1950. Although it is for there standard magnetic cartridge, it is functionally the same as the Seeburg-Pickering Blackhead.

From careful reading of it, you can see what type of grease they used and how they did in fact use a little rubber seal. The rubber in these is NOT related to the electro-mechanical operation of it. It is just a grease seal.

It looks like also that depending on the Saybolt viscosity you can increase or decrease the dampening of the cartridge.

Anyone care to opine on if the blackheads could use more or less dampening?

Interesting read. If anyone wants a copy of the PDF, drop me an email directly and I will forward it to you. (JDD@8bells.com)

Best, James

Hi James,
Can you post a link to it here ? Seems odd that it is from 1950--they made the A cart at least two years earlier ? Ron Rich

You'd think by now they'd abandon such a crude mechanical arrangement in favor of something more refined.
That's an ugly system of translating wiggles into sounds.
I'd sooner play my records with a nail.

In this particular case the Patent is for a sealed unit. Looks like they poured plastic around the guts with the grease in it during the pour. The year is 1951 and granted in 1956. The engineering discussion however is no doubt the same for the blackheads. Patent Number 2,749,393


James

What is ironic is that by the time a patent was granted the cart was obsolete as least as far as Pickering's product line.

They went to hermetically sealed construction with removable armatures in 1952 and 1953 for both home and jukebox applications.

Rob/NYC