DECTape head problem

[Mike Katz]

I wonder if there are any professional audio multi-track recorders that 
match the tape width, number of tracks and tack pitch and have the 
necessary frequency response.

On 2/7/2022 3:05 PM, Marc Howard via cctech wrote:
> 8 track tapes use 1/4" wide tape.  Most 8 track units use heads with only
> two tracks implemented.  There was a stepper solenoid that moved the head
> down (or up after all 4 stereo programs were played).  Growing up in the
> 60s you never forget things like listening to In-A-Gadda-Da_Vida fade in
> the middle of the drum solo and a loud "klunk-klunk" sound and the song
> resuming.
>
> Some true 8 track heads were made for mastering pre-recorded tapes and
> maybe for consumer recorders.
>
> Marc
>
>
> On Mon, Feb 7, 2022 at 12:51 PM Michael Thompson via cctech <
> cctech at classiccmp.org> wrote:
>
>> DECtapes have 5x redundant tracks. If you could find an 8-track head that
>> had the same track pitch, and maybe track width, you could read the tape
>> but lose redundancy on the Mark and Timing tracks. That probably would not
>> work with a marginal DECtape.
>>
>> On Mon, Feb 7, 2022 at 3:33 PM Wayne S <wayne.sudol at hotmail.com> wrote:
>>
>>> I’ve often wondered if the tape heads from consumer tape devices such as
>>> cassette or 4-8 track tape players could be used or be made to be used as
>>> replacements. Anybody ever try that?
>>>
>>> Sent from my iPhone
>>>
>>>> On Feb 7, 2022, at 11:51, Michael Thompson via cctech <
>>> cctech at classiccmp.org> wrote:
>>>> 
>>>>>
>>>>> From: Gary Oliver <go at aerodesic.com>
>>>>> Subject: DECTape head problem
>>>>>
>>>>> In debugging my DECtape interface lashup, I found that one of my head
>>>>> has two open windings.? Specifically, one channel has an open 'ground'
>>>>> with the other two lines apparently the full winding of the channel.?
>>>>> The second channel failing has no continuity between any of the three
>>>>> lines.? I have tested the other head and it has all the requisite
>>>>> continuity so I'm hoping I can at least get a single spindle running.
>>>>>
>>>>> Has any ever attempted repair of one of these?
>>>>>
>>>>> -Gary
>>>>>
>>>> At the Rhode Island Computer Museum we found several DECtape heads on
>>> TU55
>>>> and TU56 drives with open connections. A volunteer got one head X-Rayed
>>> so
>>>> we could see the solder joints between the tiny wires for the head
>> coils,
>>>> and the larger twinax wires that go to the relay board. We couldn't see
>>> any
>>>> damage to the wires or solder joints.
>>>>
>>>> We tried heating the potting material to soften it, and digging it out
>> to
>>>> get to the solder joints. While digging at the potting material you
>> can't
>>>> see the tiny wires, so they will likely get damaged.
>>>>
>>>> We considered using a solvent to remove the potting material, but
>> thought
>>>> that it would eat the enamel off the head coil wires and damage them
>>> beyond
>>>> repair.
>>>>
>>>> So far we haven't found a way to repair the heads.
>>>>
>>>> Michael Thompson
>>
>> --
>> Michael Thompson
>>