[R-390] R390/Solid State

Thu, 8 Aug 2002 16:31:53 -0700

The last thing you need to worry about wearing out in an R-390/R-390A are
the tubes.  How many have you had to replace so far?  You'll wear out the
knobs before you go though the thousands of hours available in standard tube
life, and the R-390 series treat tubes very gently.

73 de Bill, AB6MT
[email protected]

----- Original Message -----
From: "Steve Goode" <[email protected]>
To: "Michael Young" <[email protected]>; <[email protected]>
Sent: Thursday, August 08, 2002 3:55 PM
Subject: Re: [R-390] R390/Solid State

> Mikey,
>
> Here is a copy of an email I sent to this list in January when another
> person mentioned converting a 390 to solid state.  I have not gotten any
> farther than looking at the QST article.
>
> 73,
>
> Steve, K9NG
>
> ==========================
>
> Alright!  I must confess that I have had similar evil thoughts.
>
> WARNING---SAND STATE THOUGHTS TO FOLLOW!!!!
>
> I love the way my R-390A performs.  Right now the only sand in it is the
> Navy approved power supply changes.  It even has a working ballast tube.
> But I want this receiver to work forever!  So what happens when I run out
of
> tubes?  My thoughts are that anything behind the mechanical filters is
fair
> game since that should have minimal performance hits in dynamic range,
> sensitivity, etc.  So I was thinking of looking at the IF, detector, agc,
> calibrator circuits to start experimenting on.  What I have found so far
in
> discussions with others who have actually done solid state conversions is
an
> article from the April 1977 QST (it is not the April fool article).  This
> article shows how to make plug in solid state replacements for any tube
> using JET or MOSFETs in cascode with high voltage transistors.  This is as
> far as I have gotten.  Anyone else willing to confess?  Anyone actually
> succeeding in doing a solid state conversion?
>
> Steve, K9NG
>
>
>
>
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