8mm Forum: New nylon Magnetic Head pressers

»	8mm Forum » 8mm Forum » New nylon Magnetic Head pressers

UBBFriend: Email this page to someone!

Author

Topic: New nylon Magnetic Head pressers

Andrew Woodcock
Film God

Posts: 7477
From: Manchester Uk
Registered: Aug 2012

posted August 04, 2015 06:54 AM

I posted a while back stating that there is deterioration to the sound quality lately on the balance side of my Beaulieu stereo probably due to the onset of wear to the narrow balance side of the main recording and playback head on the projector.

I also spoke of requiring the correct wiring configurations as the original factory method of wiring into the head conceals the wiring colours for each of the four terminals.

I am still not 100% certain regarding this if anyone can advise, but just through trial and error I have noticed that on some occasions the sound can be perfectly fine.

This initially struck me as being just due to the quality of the track or in some cases the lack of quality on this side of the track making the difference between the two.

After further investigating I have now come to realize the majority of the problem appears to be due perhaps to wear also on the nylon magnetic head pressers as with a slight amount of pressure applied to the exposed tops of these on the balance side, all sounds fine on the high ends just as in the same way it is on the main side of the track.

I would like to know if anyone has just changed out the nylon pressers for new on either these machines or in fact any other twin track or stereo machine and would it benefit me to do so?

Do these wear just as quickly if not quicker than the actual heads themselves?

This, I have to say, is a job I have never needed to do before on any machine I own.

It would certainly be my prefered option to do this before changing the magnetic head also, due to the uncertainties expressed above with the wiring configuration.

Any comments and help from those who have carried out this type of work on their machines would be gratefully received as always.

Thanks in advance for any advice given.

[ August 04, 2015, 03:54 PM: Message edited by: Andrew Woodcock ]

--------------------
"C'mon Baggy..Get with the beat"

| IP: Logged

Maurizio Di Cintio
Jedi Master Film Handler

Posts: 977
From: Ortona, Italy
Registered: Jan 2004

posted August 04, 2015 09:26 AM

Hi, Andrew. The fact you get better sound playback when tinkering with the pressers is but one more clue to the fact the sound head has started wearing: it's not a matter of presser's wear: because the wear on the heads surface flattens its somewhat curved profile, the presser will non longer press the track with enough strength so as to allow proper head to track contact, resulting in high freq loss. Please consider the effect is doubled because you lose high freq during recording AND during playback. Although in the long term it's certainly possible pressers need replacement, the first (and possibly only) culprit is probably the head. More to it: track 2 heads wear faster because they are narrower AND track 2 is less smooth and more uneven than track 1 due to sprocket proximity: achieving optimal contact is more difficult even when the head is just new... I think what you complain about is perfectly logical, but once you changed the head, everything will be OK, I am 80% positive.

--------------------
Maurizio

| IP: Logged

Andrew Woodcock
Film God

Posts: 7477
From: Manchester Uk
Registered: Aug 2012

posted August 04, 2015 03:48 PM

Thank you Maurizio for your kind and informative words of wisdom on these matters.

It is as first suspected then Maurizio, so I shall plan to change both the head and the nylon pressers for new.

Now I just need some definite conclusive answers for the wiring configuration, then all work can be carried out.

Hopefully someone here will be able clarify the wiring colour configuration?

Thanks once again Maurizio, I am certain your prognosis is 100% correct on this one.

[ August 04, 2015, 05:03 PM: Message edited by: Andrew Woodcock ]

--------------------
"C'mon Baggy..Get with the beat"

| IP: Logged

Andrew Woodcock
Film God

Posts: 7477
From: Manchester Uk
Registered: Aug 2012

posted August 05, 2015 05:35 AM

I shall ask again, anyone know the wiring configuration on these please?

--------------------
"C'mon Baggy..Get with the beat"

| IP: Logged

Maurizio Di Cintio
Jedi Master Film Handler

Posts: 977
From: Ortona, Italy
Registered: Jan 2004

posted August 05, 2015 09:02 AM

Andrew, is there no way to pull the actual ceramic head out of its metal shield/shell? This way you'll certainly be able to see how the wires are soldered. I am asking because these heads look very similar to Eumig's head for Series 800 projectors whereby the the actual head is encased in a metal shell (hum shield?) but it can easily be pulled out of it. Have you had a look to these heads from the bottom? If there is a way to remove them from said shell, it should be apparent by watching them from the bottom (stripe contact side).

--------------------
Maurizio

| IP: Logged

Andrew Woodcock
Film God

Posts: 7477
From: Manchester Uk
Registered: Aug 2012

posted August 05, 2015 09:32 AM

Hello again Maurizio, thanks for the reply.
You are correct Maurizio,you can indeed separate the outer head shell from the remainder of the head including both coils.

I know the assembly of these heads quite well as they are used on all Bauer Studio line machines as well as the Beaulieu Stereo models.

I could do what you say but I am extremely reluctant to so as this means having to de solder the head from its terminals first then pull apart the uniquely sealed cable gromit that is fitted only to these models.
The issue I have in doing so is that I wanted to leave all the cables attached to this head and de solder from the circuit board terminals and not disturb the soldering in any way on the actual head.
I intend sending this head off to be re profiled by a specialist I have used successfully in the past, just then to keep it as a spare giving me a quick and easy change out by just resoldering to the board terminals should I ever decide to use it again.

I have had many heads re profiled in the past and it does successfully give you back some decent service life with these so I was just going to send it with the cables and grommit in tact if it all possible.

My new head I was going to solder brand new cable to outside of the machine where it is much easier to do so. Then I would be left with the fairly straightforward task of soldering the new cable to the boards four terminals while in situ.

Doing the task in this manner is by far the easiest method to ensure a decent solder job is carried out.

--------------------
"C'mon Baggy..Get with the beat"

| IP: Logged

Maurizio Di Cintio
Jedi Master Film Handler

Posts: 977
From: Ortona, Italy
Registered: Jan 2004

posted August 05, 2015 10:17 AM

I see. I can't help inany way, though, I've never owned a Beaulieu.
Best of luck.

--------------------
Maurizio

| IP: Logged

Andrew Woodcock
Film God

Posts: 7477
From: Manchester Uk
Registered: Aug 2012

posted August 05, 2015 10:28 AM

Thanks anyhow Maurizio, you have already helped with your suggestions so thanks again. [Smile]

Hopefully an owner who has replaced these or someone like Bjorn who worked at Beaulieu would know and perhaps may post.

Here's hoping. [Confused]

The schematics really don't make this detail clear.

Once I find out for certain, I will post on here a drawing for future reference to all owners.

--------------------
"C'mon Baggy..Get with the beat"

| IP: Logged

All times are Central

Printer-friendly view of this topic

UBB.classic^TM 6.3.1.2