• Get involved.
    We want your input!
    Apply for Membership and join the conversations about everything related to broadcasting.

    After we receive your registration, a moderator will review it. After your registration is approved, you will be permitted to post.
    If you use a disposable or false email address, your registration will be rejected.

    After your membership is approved, please take a minute to tell us a little bit about yourself.
    https://www.radiodiscussions.com/forums/introduce-yourself.1088/

    Thanks in advance and have fun!
    RadioDiscussions Administrators

Ampex ATR 700 issues

S

SFM-Ptgal

One of my vintage items (Ampex ATR 700) has a big issue... The machine simply doesn't rewind (It isn't a motor problem because it turns while on playback) and the capstan dies while turning the vari-speed on. This last problem doesn't matter that much to me. My priority is the FRew.


Is anyone here aware of some typical issue on that model machine that might help to trace the problem?

Pedro
 
It's the buttons...the membrane things they use are known for their high failure rate. Every ATR-700 out there had 'em changed at least once.

I doubt you can find replacements, but you probably can rig up some kind of remote button.
 
LA_Guy said:
It's the buttons...the membrane things they use are known for their high failure rate. Every ATR-700 out there had 'em changed at least once.

I doubt you can find replacements, but you probably can rig up some kind of remote button.
Click to expand...

I've already shunted the remote contacts for FRew and it didn't work at all ::)
 
Smells like burned contacts on the relay that switches in the rewind motor. It will work in play because in the play mode, voltage is fed through a dropping resistor to keep the motor turned on just enough to provide some tension on the feed. In rewind, this resistor is switched out and the full voltage fed the rewind motor by a relay. Or that is what is supposed to happen. Here it would appear that either the relay is not kicking in, or the contacts have been burned up and no voltage reaches the motor at all.
 
TomT said:
Smells like burned contacts on the relay that switches in the rewind motor. It will work in play because in the play mode, voltage is fed through a dropping resistor to keep the motor turned on just enough to provide some tension on the feed. In rewind, this resistor is switched out and the full voltage fed the rewind motor by a relay. Or that is what is supposed to happen. Here it would appear that either the relay is not kicking in, or the contacts have been burned up and no voltage reaches the motor at all.
Click to expand...

Isn't it hard to believe a relay getting it's contacts burned? Must be an outside factor, current overdriving it?::)
 
SFM-Ptgal said:
Isn't it hard to believe a relay getting it's contacts burned? Must be an outside factor, current overdriving it?::)
Click to expand...

No it happened all the time when relay switching was "state of the art." Most good engineers kept a few spare relays in stock. They are still fairly easy to find and not very expensive.

As a temporary fix, you may be able to unplug the relay, remove the cover and burnish its contacts with emery paper, or even a finger nail file.
 
Chuck said:
SFM-Ptgal said:
Isn't it hard to believe a relay getting it's contacts burned? Must be an outside factor, current overdriving it?::)
Click to expand...

No it happened all the time when relay switching was "state of the art." Most good engineers kept a few spare relays in stock. They are still fairly easy to find and not very expensive.

As a temporary fix, you may be able to unplug the relay, remove the cover and burnish its contacts with emery paper, or even a finger nail file.
Click to expand...

I'll take a look at it. I'm guessing it'll be a pitb because all on that machine is soldered, even the fuses. With a bit of luck the relays aren't :p I'll swap with the FF one...
 
The ATR 700 was just like a TEAC 7030 with different style buttons, was similar to a 25-2 deck. The buttons were a big problem as mentioned before, also the relays are place to look at...also mentioned as well. BTW did you get your Gates Stereo 80 working?

Lane
 
Well... Murphy's law at it's best: The relays are soldered and one of the screws that old the pcb that contains them is stucked: it turns hardly and won't unscrew. It's head is almost sc%&wd I don't know what to do now :'(
I need to removed that pcb so that I can check the relays for a start.
 
I would see if you can find a replacement for that relay before you go much further. If you have to un-solder it you might as well replace it. Getting the PCB board out first--try a small pair of vise-grips to muscle the screw out. Two other options--neither very good, once you can get to the relay:

A temporary fix which may work--or finally kill it--is to punch a small hole in the cover and squirt something like isopropyl alcohol (or cheap vodka ;)..) into the relay, and let it swish around, then dry out. Obviously with the power off and disconnected!

Another alternative is to carefully cut away the plastic "dust cover" to expose the contacts. If you can do this without destroying the relay you might be able to burnish the contacts enough to get it working.
 
Or just devote that ATR to door stop duty, and buy a used Otari MX5050BII on E-bay. :)

Considering we're in an era of vanishing open reel use, it might be easier in the long run to scalvage another machine.

Incidently I heard Quantegy got out of the open reel tape manufacturing business altogether.

I guess once whatver is left of their stock is finally sold, there won't be a source for new open reel tape.
 
Status
This thread has been closed due to inactivity. You can create a new thread to discuss this topic.


Back
Top Bottom