[R-390] R390 VS 390A

[Barry Hauser]

Hi Xu:

You wrote:
>  I know that R390 is better than R390A,but the R390A with mechanical
> fiter,I think the R390A have better selectivity than R390,is that right?

Actually, it's more of a yin-yang situation.  The non-A (yin) has LC
filtering, generally equivalent selectivity, but with smooth rolloff -- not
as steep of course, but better for audio quality.  The R-390A has steep
skirts with the mech. filters, but sometimes there is ringing and lately,
there seems to be a higher failure rate of the filters (as they age?).
Better for SSB, but not as good for sound quality, hence designated "yang".

> and R390 can match CV591,Does V591 can match with R390?

I believe both A and non-A work with the CV-591 and the older, bigger SSB
converter (CV-157?).

>where can I find a homemade SSB adaptor for R390?

You can get a solid state SSB converter, the PD-1 from Ron Hankins.
Unfortunately, the links/URL's I have for him are not working.  About $100
as I recall.

For homebrew and mods, take a look at
http://www.r-390a.net/SSB-conversion.pdf

Hope this helps.

Barry