Melos Echo Chamber, EM120 from 1979

[N_Cook]

Compact Analogue tape loop uses Apollon HD5000 small "8 track" cart and
very long tape loop. In very good internal appearance.
No tape transport , but motor and spindle is fine. Too much resistance
to tape motion inside the cart initially thinking due to plastic on
plastic bearing, but probably due to brake arm not pulling away from rim
of tape reel. The pinchwheel moves inwards against its back spring in
play mode, so perhaps not a case of shrunk pinchwheel. Perhaps the cart
internal brake arm has bend over time, I'm thinking reduce the spring
action firstly as that seems might strong for a tape reel that is never
FF or REW fast.
I bet Daphne Oram would have liked all that length of tape inside a
small cart , instead of being looped all around her work space.

 

[N_Cook]

Looks, although pinch wheel is not soft or hard, the surface has gone
micro-crazed. As much bigger than C90 type cassette player pinch wheels,
will try a piece of silicone rubber tube stretched over the original. A
sensible use for a selfie-stick, using the silicone grip removed from
the handle.
Motor is dated 1979 but perhaps a replacement and the m/c is earlier,
the pcb looks typical late 1960s

 

[N_Cook]

Selfie handle was too thick, stretched-on some silicone sleeving using
farmer's castration pliers. Made little difference. I think the problem
is the way the tape is taken off the inside of the reel of tape, at an
angle and so if the tape is sticky with age , there is a lot of
resistance there. Its a sort of continuous up-setting action.
Coupled with supply side is small diameter and take up is on the outside
so large diameter. So perhaps the tape winds on too tight if things have
gone out of balance. Next time of powering I'll add some rubber sleeve
over the spindle and try running the whole hank of tape through a few times.
Is there a dry lubricant for such situations of sticky tape, graphite
powder? talcum may be too abrasive on the heads?

 

[N_Cook]

On 27/08/2016 17:32, N_Cook wrote:

Selfie handle was too thick, stretched-on some silicone sleeving using
farmer's castration pliers. Made little difference. I think the problem
is the way the tape is taken off the inside of the reel of tape, at an
angle and so if the tape is sticky with age , there is a lot of
resistance there. Its a sort of continuous up-setting action.
Coupled with supply side is small diameter and take up is on the outside
so large diameter. So perhaps the tape winds on too tight if things have
gone out of balance. Next time of powering I'll add some rubber sleeve
over the spindle and try running the whole hank of tape through a few
times.
Is there a dry lubricant for such situations of sticky tape, graphite
powder? talcum may be too abrasive on the heads?

Disabled the braking.
Some rubber sleeving over the drive spindle and some graphite powder
laid over the top of the tape reel. Run it like that for 20 minutes,
removed the sleeving off the spindle and its been running fine since,
even at the slowest motor speed. Except for a coupled of sections of
ruckled tape running over the heads. Left the sleeving stretched over
the original pinch wheel.
The 2 dogs that keep the cart in place , spring action no longer strong
enough to keep the cart in regular contact with the heads , so a couple
of blocks of rubber each side and cable ties around offset that.

 

[N_Cook]

JIC any farmers out there, replace livestock for farmer.
The tape now runs as easily as a C90.
I doubt the owner will pay >30GBP for a refurbished cart.
Presumably there was a label on the echo chamber casing originally , why
there is a hinged back flap to this. As the spindle and pinchwheel and
tape are always engaged, with or without power, the rear lid muist be so
you can manually disengage the tape drive after each use.
For anyone re-taping a cart, count off the turns of tape and its overall
length. Assuming you would splice the tape off the cart, then for n+0.5
turns on the reel, you would have to put n turns in the tape , in the
correct clockedness, before splicing.