Sony DAT audio DTC 690 drum assembly/ DOU-03A/ 8-848-567-11
Initially, anyone know how to get the top drum off, I don't want to heat
up to separate interference fit , if there is some secret fixing.
Then anyone happen to know if video heads are the same, they look the
same via what little I can see of them.

"N_Cook" wrote in message
...
Sony DAT audio DTC 690 drum assembly/ DOU-03A/ 8-848-567-11
Initially, anyone know how to get the top drum off, I don't want to heat
up to separate interference fit , if there is some secret fixing.
Then anyone happen to know if video heads are the same, they look the same
via what little I can see of them.



Video heads are a damn sight bigger than DAT heads, but the principle of
operation is exactly the same.
Some portable DAT players used an even smaller head, but you had to wrap
more than 90 degrees of tape around it to compensate, not good in terms of
tape friction/tension etc.

I used to fix a lot of DAT's, but never once felt inclined to take a head
apart.



Cheers,

Gareth.

"N_Cook" wrote in message
...
Sony DAT audio DTC 690 drum assembly/ DOU-03A/ 8-848-567-11
Initially, anyone know how to get the top drum off, I don't want to heat
up to separate interference fit , if there is some secret fixing.
Then anyone happen to know if video heads are the same, they look the same
via what little I can see of them.


BTW, if you remove the head or move anything else, you will need to realign
the tape path, and you won't be able to do that properly without an
alignment tape.

Ideally you also need a tension tape to measure and adjust back tension.



Gareth.

On 05/09/2013 15:06, Gareth Magennis wrote:
"N_Cook" wrote in message
...
Sony DAT audio DTC 690 drum assembly/ DOU-03A/ 8-848-567-11
Initially, anyone know how to get the top drum off, I don't want to heat
up to separate interference fit , if there is some secret fixing.
Then anyone happen to know if video heads are the same, they look the same
via what little I can see of them.


BTW, if you remove the head or move anything else, you will need to realign
the tape path, and you won't be able to do that properly without an
alignment tape.

Ideally you also need a tension tape to measure and adjust back tension.



Gareth.



I can't make things worse. Smashed up heads, probably from foam breaking
up / snagging on the silly "head-dirtier" arm

"N_Cook" wrote in message ...

On 05/09/2013 15:06, Gareth Magennis wrote:
"N_Cook" wrote in message
...
Sony DAT audio DTC 690 drum assembly/ DOU-03A/ 8-848-567-11
Initially, anyone know how to get the top drum off, I don't want to heat
up to separate interference fit , if there is some secret fixing.
Then anyone happen to know if video heads are the same, they look the
same
via what little I can see of them.


BTW, if you remove the head or move anything else, you will need to
realign
the tape path, and you won't be able to do that properly without an
alignment tape.

Ideally you also need a tension tape to measure and adjust back tension.



Gareth.



I can't make things worse. Smashed up heads, probably from foam breaking
up / snagging on the silly "head-dirtier" arm



Or someone trying to clean them with a cotton bud or something.
I always used to use ordinary copy paper soaked in alcohol, so you can feel
with your fingertip exactly what is happening to the heads as they are
cleaned.


If you ever get into a position where you get this working, I can give some
tips how to attempt a realignment without an alignment tape.



Cheers,

Gareth.

I managed to make a small hub puller out of an old pair of basic wire
strippers and circlip pliers and a minute of low heat from a hot air gun
to pull the 6 pole magnet disc from the underside, without damage. After
taking measurements of the 2 gaps, to the nearest thou. Next week I'll
try removing the top disc from the middle disc, again interference fit
and again nothing to really get a hold of for hub pulling action.
Probably will be some protective tape around the bottom drum (non tape
path part) then a l
jubilee clip as I don't think the few 1.5mm threaded holes in aluminiun
would take the strain.

"N_Cook" wrote in message ...

I managed to make a small hub puller out of an old pair of basic wire
strippers and circlip pliers and a minute of low heat from a hot air gun
to pull the 6 pole magnet disc from the underside, without damage. After
taking measurements of the 2 gaps, to the nearest thou. Next week I'll
try removing the top disc from the middle disc, again interference fit
and again nothing to really get a hold of for hub pulling action.
Probably will be some protective tape around the bottom drum (non tape
path part) then a l
jubilee clip as I don't think the few 1.5mm threaded holes in aluminiun
would take the strain.



Good luck, I have always assumed these things are assembled with the idea
they will never have to be disassembled.



Gareth.

N_Cook wrote:
On 05/09/2013 15:06, Gareth Magennis wrote:
"N_Cook" wrote in message
...
Sony DAT audio DTC 690 drum assembly/ DOU-03A/ 8-848-567-11
Initially, anyone know how to get the top drum off, I don't want to heat
up to separate interference fit , if there is some secret fixing.
Then anyone happen to know if video heads are the same, they look the same
via what little I can see of them.


BTW, if you remove the head or move anything else, you will need to realign
the tape path, and you won't be able to do that properly without an
alignment tape.

Ideally you also need a tension tape to measure and adjust back tension.



Gareth.



I can't make things worse. Smashed up heads, probably from foam breaking
up / snagging on the silly "head-dirtier" arm

nice.

just curious, who even sells DAT heads, let alone in 2013?

Good question. ASTI doesn't have them and everyone who says they can backorder them prices them at arouind $800.

Gotta have a real need.....

On 06/09/2013 20:40, Cydrome Leader wrote:
N_Cook wrote:
On 05/09/2013 15:06, Gareth Magennis wrote:
"N_Cook" wrote in message
...
Sony DAT audio DTC 690 drum assembly/ DOU-03A/ 8-848-567-11
Initially, anyone know how to get the top drum off, I don't want to heat
up to separate interference fit , if there is some secret fixing.
Then anyone happen to know if video heads are the same, they look the same
via what little I can see of them.


BTW, if you remove the head or move anything else, you will need to realign
the tape path, and you won't be able to do that properly without an
alignment tape.

Ideally you also need a tension tape to measure and adjust back tension.



Gareth.



I can't make things worse. Smashed up heads, probably from foam breaking
up / snagging on the silly "head-dirtier" arm

nice.

just curious, who even sells DAT heads, let alone in 2013?


Available at Megabucks.
Discovered one thing, so far. There are 2 magnets on the disc I removed.
The disc is probably mu-metal with strong 6 pole motor magnet below and
a weak thin disc above to energise a castellated pcb track for a tacho.
I suppose the mu-metal is to stop the rotating main field from directly
coupling with the heads or the transfer coils,one pair is static and one
pair rotating relative to the magnets wheras the video heads are static
relatively speaking, and the weak one is too weak to affect more than a
couple of mm away from it

I've decided , when I get back to it , to drill matching 8 holes in a
plate and hope 8x 1mm screws, 5 threads each, will hold in place while
trying to separate the 2 drums

Here is a rare beast, pics of innards of a DAT drum
http://www.diverse.4mg.com/DAT.jpg
top views at top, 1mm squared paper and one of the 1mm screws I used.
The ring of white dots in image lower1 is where the middle ferrite disc
was superglued? to the central boss. I tried 20 seconds of 300 deg C
heat and trying to break the bond with a screwdriver blade, cracked the
ferrite, so the splodges are my superglue additions. 30 seconds of heat
and a smell of varnish or something and the bond broke.