Friday, November 17, 2006

Eton E1 - What's Up With Its Stability?

Several commentators (i.e. Guy Atkins and me...) have noticed the 50-150 Hz (mostly 50) frequency error which is noticeable and annoying when doing ECSS tuning. As Guy found it, there is a trimpot in the rear which allows for easy adjustment. Still, I found during the KONG DX-peditions, which went for like four weeks, that I needed to readjust two or three times even though the radio was never switched off during that period.

I went back to Kongsfjord last night after a two-week break to DX a bit. I don't usually heat the house when not in use, and November is usually quite cold at these latitudes, so the temperature in the living room was only 2C. I switched the E1 on and allowed it to warm up for an hour while I used all available heating sources to warm up the room. After an hour, the temperature was a more pleasant 18C and I started testing the E1. It was 180 Hz off!!! During the next two hours it came down to 130 Hz off, at which point I adjusted the trim pot. Some hours later I had to readjust it the other way but only 30-40 Hz.

Really! I mean, are all E1's like that? If you use AM or AMS the problem isn't there of course, but accuracy is critical for ECSS tuning. Of course I don't expect to find a TCXO in it, but can't it get any better? I would appreciate comments from E1 users who use ECSS frequently.

This is posted both in my blog and the E1 Yahoo Reflector.

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