TM500 plug in extension cables.


I notice there have been many comments about the problems with such a cable, especially with regard to the pass transistors inside the frame. Here's a few comments of my own:

1. the transistors in the frame are very low gain and slow (low ft), and not really prone to oscillation.
2. the factory extension cable works fine, and has no special features other than heavy wire (flat cable) on those power connections.
3. I have used the factory extender, and several ones made by group members (all of which just go pin to pin with individual wires) without ever once encountering the slightest difficulty caused by the cable.

I believe it is true that an extension cable made of too light a wire gauge (such as 28ga ribbon cable) WOULD be a problem as it introduces too much ground loop resistance which could lead to feedback and oscillation that would be highly plug in dependent. I would suggest to those wanting to do lots of plug in repairs, that a TM501 or TM502/A with the cover removed for access is far and away the best possible method to run the plug in and carry out any service. I also have a TM5003 skeletonized for this purpose.

just my $0.02 worth on this topic. your mileage may vary.
all the best,
walter (walter2 -at-
sphere research corp.


I agree with Walter, I find that a TM502 core works well for single and double width plug in repair.