Troubleshooting a univox ec-80a

[z7yh]

I picked up a univox ec-80a for dirt cheap and I am trying to get it working. The problem is not the tape, because I have another unit and I swaped a known working tape. the transport is working and when I turn the echo delay knob it speeds up and slows down. the signal just seems to pass through the unit the same way it does if there is no tape in it. Is there a way to test the heads? any ideas? thanks

[tiges_ tendres]

from my experience with the ec 80, there are usually a few issues.

There are three trim pots on the board, all of which need to be set just so in order to get much of a sound.  You will notice when you turn one, that the transport really speeds up and makes an awful noise.  The other two are very subtle, but have to be correctly set.

I dont have a multi meter, so I don't know what ohmage they are set to. 

As for "when you turn the echo delay knob it speeds up and slows down"  Do you mean the motor? or the delayed signal?  I'm guessing as you aren't getting a delayed signal, you mean the motor.  Mine does the same thing, and I do notice a difference in the length of the echo.  So that sounds like it's a goer!

My problem is that the felt behind my tape is worn out, so I have to jimmy some sponge in the gap to get it to work.  If you or anyone has those felts, let me know!  Finding the tapes on ebay is hit and miss, and they usually sell for more than I bought my unit for!

one thing that might help is there is a plastic shell which clips the tape in place.  I usually take this off so I can force better contact with the tape heads.  Someone will have to play whilst you experiement but this might yield some fruit!

Happy (echo) trails!

[Mark Hammer]

The thing that a lot of folks who grew up in the era of digital don't always appreciate fully is that small distances mean a lot when it comes to tape.  A little bit of grime build up on the tape head, or a wee bit of head misalignment - whether sie-to-side or front-to-back, and you insert a gap of a couple of mils.  And in the world of tape, distances the thickness of paper can change everything.

[z7yh]

There are three trim pots on the board, all of which need to be set just so in order to get much of a sound.  You will notice when you turn one, that the transport really speeds up and makes an awful noise.  The other two are very subtle, but have to be correctly set.

I have 2 of these so I can set them to the same as the other unit but that Isn't nessasaraly the right setting for this one but i'll give it a shot

As for "when you turn the echo delay knob it speeds up and slows down"  Do you mean the motor? or the delayed signal?  I'm guessing as you aren't getting a delayed signal, you mean the motor.  Mine does the same thing, and I do notice a difference in the length of the echo.  So that sounds like it's a goer!

yes I meant the motor

My problem is that the felt behind my tape is worn out, so I have to jimmy some sponge in the gap to get it to work.  If you or anyone has those felts, let me know!  Finding the tapes on ebay is hit and miss, and they usually sell for more than I bought my unit for!

the felts are pretty flat but it works in the other machine and the heads are in there pretty far, luckily the guy I got them from wasn't storing the tapes in the slots. I figured after I get it working I would pull the felts and glue a small sliver of sponge in then glue the flat felt on top of the sliver of sponge.


thanks

[z7yh]

The thing that a lot of folks who grew up in the era of digital don't always appreciate fully is that small distances mean a lot when it comes to tape.  A little bit of grime build up on the tape head, or a wee bit of head misalignment - whether sie-to-side or front-to-back, and you insert a gap of a couple of mils.  And in the world of tape, distances the thickness of paper can change everything.

I grew up in the tape age I aligned lots of cassette decks. I even had an 8-track when I was a kid but I never aligned the heads in that.
I tried to align the heads but it didn't seem to make any difference at all. If that was it I should hear some difference in the sound while changing the position of the heads, but nothing not any change at all.

[z7yh]

I took the wires off the heads, and on the working unit the playback head is a little over 300 ohms and on the broken unit its an open circuit so I guess its the playback head. So is this thing useful for anything, I have a feeling tracking down the head would cost more than its worth. would the head from an old 8-track player work if its not too wide?
thanks dave