Here's what's going on with my quest to get a replacement Eton E5 power adapter that doesn't introduce interference:
I wrote to Eton directly to tell them about the problem I had with my E5 adapter. I described where and when I bought the radio, and how the adapter introduced interference but the batteries did not. I have not yet heard back.
Then I wrote to Universal Radio, who sold me my E5. I told them the same thing about the adapter problem. They wrote back a couple days later to tell me that they contacted Eton about the problem. But Eton hasn't responded to Universal Radio either.
So we wait, even for acknowledgement.
Passband receiver news is a good place to watch for news on this issue.