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@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.su...@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@classiccmp.org> wrote: > > > > > > > > >> > > >> > > >> From: Gary Oliver <g...@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 >