Richard Knoppow wrote:

I am curious what you found lacking in the 51J compared to the
other receivers?

Selectivity. The crystal filter really stinks, compared with the Collins
mechanical filters.

I had a 51J for a few years and traded it up for an R-390. Ergonomically
I liked the sliderule tuning on the 51J more, and the audio quality was
better, but the mechanical filters on the R-390 were a lifesaver.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."