TK50's and TK70's have a bad rap for this. The key problem is twofold:
1) Tapes stored in dungeons tend to be crap and shed stuff
2) The capstans on the TK50 are very important and need to be lubricated
For the first, I go with good quality tapes and before I put a tape into
my collection I clean the heads, then run the tape through a backup or
two then check the heads. If dirty I pitch the tape and clean. If clean
I clean the heads again and put it in service. Same process you should
go through with any new magnetic media (RL02, RX01, etc....)
For the second you really need to take the drive apart, remove the bolts
on the front and rear capstans (marking the bolt's orientation and how
many turns to take off) and lubricate the bearings with fine watch oil.
They should spin easily the whole problem is the oil dries out and since
they use tape friction to turn and the rear one is connected to a
tachometer having them drag will drive the tape unit insane and lead to
unspooled tapes, read problems, all sorts of insanity.
Remember they don't have tension arms, the capstans are how they figure
everything out.
Aside from that, fine. I use mine as backups with no issues. Just never
introduce a new tape without checking the heads, otherwise the crap will
get on your good tapes like an STD.
C
On 9/3/26 17:55, Rob Jarratt via cctalk wrote:
Be very careful when reading them, they will shed and stick to the
rollers. You may need to bake the tapes. See this account:
https://www.magneticscrolls.com/blog/tk50-tape-baking
Regards
Rpb
On 03/09/2026 10:05, hlep via cctalk wrote:
Hi Rod,
Do you have any external TK 50 or TK 70 tape drives?
I'm working at an archive in Germany and we've got some TK-50 tapes
and we've been looking for some hardware to access them with.
Best,
Josh
On 2026-09-03 08:37, Rod Smallwood via cctalk wrote:
Hi Guys
My DEC Collection needs downsizing.
Im in the UK so for the US only the small stuff would be worth
shipping
If you need anything PDP8, PDP11 or VAX please indicate item you
might want
Rod
