On Thu, Mar 13, 2008 at 1:43 PM, D. Chester <[EMAIL PROTECTED]> wrote:
> The mechanical filters result in tighter selectivity, but at the expense of > nonlinear phase shifts inherent to mechanical filters. That is what causes > the harsher audio quality in the A version, as well as in receivers like the > 75A-4 that use mechanical filters. A couple of other issues with the R-390 are excessive heat from the PS rectifiers and additional weight. Neither are show stoppers though, and like Don, I also prefer the original model R-390 to the later A model for overall utility. Both are excellent rigs, and pulling the audio off the rear apron diode load connections, then feeding it through a decent external audio amp will drive a big speaker with amazing audio resulting. R-390s tend to be a bit less available due to lower production numbers, but they're available without much searching. And, contrary to the new-age 'non-A' myth, both radios are indeed R-390 receivers, with the latter, cost-reduced version nomenclature appended as the A. Makes more sense to refer to a radio by what it actually is, rather than what it isn't. (o: ~ Todd, KA1KAQ ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/[email protected]/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:[email protected] To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
