On Dec 31, 8:42 pm, David wrote:
On Sun, 31 Dec 2006 23:43:00 GMT, "David Eduardo"

wrote:
Back in the early 70's, I was using an adapted parametric equalizer to aid
in DXing. I had it connected to the output of my R390 by Hammarlund and
output it to a low noise amplifier that had a headphone out. This allowed me
to do some very nice things on adjacent channels, like adjusting the audio
to match the desired station and not the interfering one, or to narrow the
bandwidth of the audio to make the weaker signal less covered by splatter...
or to remove lower frequency hets that added to the interference.

At that time, the only good parametrics were designed for broadcast and
sound reinforcement use, so matching levels and impedances was a big issue,
but I found that using this sort of device (the eq can amp cost more than
the R390, which I had bought new) on MW and tropical band DX made all the
difference in the world.

- I believe only Collins made the R-390.

David,

The R-390 was designed and Made-by-Collins.
http://www.penan.net/dx/r-390a.htm
The original Contract Date was 1951
http://oak.cats.ohiou.edu/~postr/bapix/R390.html
NOTE - A cost-reduced Second Generation Receiver was
also Designed-by-Collins and Designated as R-390A.
Under this new Contract the R-390A was made by a
number of Manufacturers including Collins.
http://www.eham.net/reviews/detail/2480
What did "Helena Rubenstien" have to do with the
Collins R-390A ? ? ?
http://www.dxing.com/rx/r390a.htm
Over 54,000 Collins designed R-390"A" models were made
by Collins and many other manufacturers including: Motorola,
Stewart-Warner, Capehart, Amelco, Teledyne, EAC, Fowler Ind.,
Dittmore-Freimuth and Helena Rubenstein (reportedly).
http://www.fernblatt.net/390.html

Check-Out the Collins R-390A "FAQs"
Frequently Asked Questions WebPage
http://www.r-390a.net/

ABOUT - Collins Radio
http://en.wikipedia.org/wiki/Collins_Radio

"Collins Radio Quick Reference" by KK6HY
http://www.wa3key.com/kk6hy.html

yes more than you wanted to know ~ RHF