[Elecraft] rcvr designs prc-2000 USES DIRECT CONVERSION!

[Geoffrey Mackenzie-Kennedy]

Another example is the Collins 95S-1A produced some years ago. This receiver
is 'Software Driven' and covers the range from 5 kilohertz to 2 GHz in steps
down to 1Hz. Its architecture is hybrid. Antenna signals between 5 kHz and
30 MHz are upconverted to 51.2 MHz and directly converted from there to
baseband - e.g. audio.  Antenna signals between 20 MHz and 2 GHz are
Directly Converted to baseband, and yes there is an overlap between 20 MHz
and 30 MHz. Baseband signals are processed by DSP. Modes handled are CW,
L.SB, U.SB, I.SB, FM and AM.

IMHO Direct Conversion has great performance potential, and the techniques
in circuitry developed during the past decade could perhaps make Direct
Conversion the architecture of choice sometime in the future. There is no
doubt in my mind that SSB signals sound "better" from a DC receiver,
likewise CW.

73,
Geoff
GM4ESD


----- Original Message -----
From: <WA2JJH at aol.com>
To: <elecraft at mailman.qth.net>
Sent: Tuesday, March 15, 2005 3:41 AM
Subject: [Elecraft] rcvr designs prc-2000 USES DIRECT CONVERSION!

>   He would joke about my K2 manpack. His used PRC-2000 cost over  $2000.
> The receiver used.   DIRECT CONVERSION. THEY DID FIND A WAY TO  GET RID
OFALL
> THE AUDIO  ARTIFACTS AND IMAGES THAT WERE THE REASON WHY  SUPERHET BET
DIRECT
> CONVERSION AS THE GOLD STANDARDOF RCVRS.