DAT "video" head replacement?

OK, now the URL works so I saw the picture.

I remember in later VHS days some of the replacement heads were supplied with the upper part of the rotary transformer. Are you sure this isn't like that ?

 

[N_Cook]

On 13/09/2013 14:12, jurb6006@gmail.com wrote:

OK, now the URL works so I saw the picture.

I remember in later VHS days some of the replacement heads were supplied with the upper part of the rotary transformer. Are you sure this isn't like that ?

Wherever they intended you to replace the top disc of a VCR they always
supplied good mechanical fixing points for clamping to, to break the fit
to the bearing. Not in this case 7x 1mm , 5 thread deep, tapped holes
were just there for holding motor to drum and drum to deck. The threaded
holes would be at least 3mm for any mechanical loading in extraction.

 

[Cydrome Leader]

jurb6006@gmail.com wrote:

"And just one more thing, the Alignment Tapes required to align the tape path
I believe were specially recorded with no ATF signals,"

OK, so they were separate frequencies, not the carriers.

However the lack of ATF signals is not required to align the deck. You still just align it, although you might confuse the system.

Most likely with a print you can find a way to disable the ATF system altogether, even if you have to disconnect the output from the heads. Believe me it can be done and should be done on a customer tape recorded previously in that machine, partly because compatability with other machines is not likely to be a big issue. For alignment I would get the tape tension as low as possible.

You know they said you needed all this equipment to align the old VHS recorders that had pots for the FM deviation and frequency and all that shit. Know what I did ? I just coupled the record signal to a deck "playing" a blank tape and "tuned it in". There is almost always a way, and remember, they are in business to make money.

ha!

 

[Gareth Magennis]

"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in message
news:l0r3ol$7q9$1@dont-email.me...

"Gareth Magennis" wrote in message news:7m7Yt.64150$Gn7.17824@fx22.am4...
"William Sommerwerck" wrote in message news:l0qutd$k0i$1@dont-email.me...

The main difference is, I believe, that DAT kind of reads 3 tracks
at once...

Kind of?


You need to do some research on the way DAT works.
It is not what is currently in your head.

Then point me to a reference. Virtually all of the online material is in
SMPTE or AES articles, which you cannot access for free.

ISBN-10: 0830636706
http://www.abebooks.com/servlet/SearchResults?isbn=9780830636709&cm_sp=mbc-_-9780830636709-_-all


I think this might be the book I bought over 20 years ago to learn how to
understand and thus repair DAT's, but I can't tell for sure because I can't
find a picture of the front cover.

Anyway, for a very small amount of money you could get a used copy and
probably learn all there is to know about how DATs work.

Then you can come back and tell us all about it! (I've forgotten most of
the details)




Gareth.

 

[William Sommerwerck]

"Gareth Magennis" wrote in message
news:2rWdncI0r6FWU6fPnZ2dnUVZ7smdnZ2d@bt.com...
"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in message
news:l0r3ol$7q9$1@dont-email.me...

You need to do some research on the way DAT works.
It is not what is currently in your head.

Then point me to a reference. Virtually all of the online material is in
SMPTE or AES articles, which you cannot access for free.

ISBN-10: 0830636706
http://www.abebooks.com/servlet/SearchResults?isbn=9780830636709&cm_sp=mbc-_-9780830636709-_-all

Thanks. I have just had my library place a hold on this book. If it find
something especially interesting, I'll post it.

 

[Gareth Magennis]

"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in message
news:l1f80b$rsp$1@dont-email.me...

"Gareth Magennis" wrote in message
news:2rWdncI0r6FWU6fPnZ2dnUVZ7smdnZ2d@bt.com...
"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in message
news:l0r3ol$7q9$1@dont-email.me...

You need to do some research on the way DAT works.
It is not what is currently in your head.

Then point me to a reference. Virtually all of the online material is in
SMPTE or AES articles, which you cannot access for free.

ISBN-10: 0830636706
http://www.abebooks.com/servlet/SearchResults?isbn=9780830636709&cm_sp=mbc-_-9780830636709-_-all

Thanks. I have just had my library place a hold on this book. If it find
something especially interesting, I'll post it.

I couldn't resist and bought a used copy of that book.

Unfortunately it's not the one I bought years ago, which was a lot more
technical. This one is a bit crap really, but does outline some of the
techniques I remember learning, and adds some other info about the format's
capabilities I don't think I ever knew about, unless it was just never
implemented.

One thing I got wrong was that recorded tracks overlap - they don't, but
instead the playback head is a fair bit wider than the recorded track, so is
in fact able to pick up the ATF signals on both adjacent tracks, thus "kind
of" reading 3 tracks at once.


Gareth.