No more hum on carrier of D-201

[Marc]

Well after a few weeks of beating my head against the wall I found the cause of the pesky hum on the carrier of my D-201.

I wish it was because of a brilliant flash of insightfulness, but it was just dumb luck.
I have been using a mobile on a power supply with no coax connected to monitor the audio from the Tram. Well to make a long story short. The mobile was to close to the edge of the bench so I went to move it, when I touched the case the hum was gone
(I had the mic keyed at the time). So I grounded the mobile that fixed the problem,
for now. I guess I need to check the power supply for a ground problem?
Any ideas would be appreciated.

Marc

[Tombstone (R.I.P.)]

Could just be a polarity problem. If your power supply has a non polarized AC plug try reversing it in the mains outlet. I think that the Tram has a three prong plug so you can't do it with the radio. If that's the problem you only need to reverse one power plug anyway. Just a chance that that's the problem. Like you say, it may be a grounding problem in your power supply.

Tombstone.