Re: [Elecraft] rcvr designs prc-2000 USES DIRECT CONVERSION!
On Mon, 2005-03-14 at 22:41 -0500, [EMAIL PROTECTED] wrote: The PRC 2000 is a hot receiver for ssb work, it sounds a little odd (but very punchy (due to the hole carved in the centre of the audio passband by the I/Q modulator / demodulator >INSTEAD OF XTAL FILTERS, STAGES OF ACTIVE OP AMPS AND AUDIO COILS AND > CAPS. OK AUDIO DSP IS USED GREATLY! the PRC 2000 uses no DSP whatsoever > THE RECEIVER IS VERY HOT. HE WORKS DX WELL. THE PRC-2000 IS ALSO 15-20W > SSB. It's also a pig to free tune but the TX audio has a lot of punch >I THINK DX OFF IS NEEDED TO SEE WHICH RADIO IS BETTER! > pHIL IS ALL FOR IT. The K2 is better, no contest but the PRC2000 is a nice radio, I can't do a side by side right now, my PRC-2000 is stuck in the northern Russian arctic as part of the 'get out' kit on northabout, www.northabout.com 73 Brendan Ei6IZ ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] rcvr designs prc-2000 USES DIRECT CONVERSION!
Gentlefolk, I am part of a group of fellow Amateurs who have been working on homebrew phasing Direct Conversion Tranceivers for a while now. Details of our first attempt can be found at: - www.stevef.demon.co.uk/qrp2k/qrp2000home.htm and the later iteration is at http://www.qrp2001.freeserve.co.uk/background.htm . Design and prototyping for the QRP2004 is well underway and will be published when we can get round to it. These are homebrew designs, the sad thing is that we were trying to get someone with more time that we have to kit them however there was little interest at the time we presented the QRP2000 at Dayton. I think we have all built, or in my case are building K2s as well. There is something about the clarity of the audio from a DC RX which superhets never manage to achieve. The first ham project I ever made was a Sudden DCRX uring the venerable NE602...I had a lot of fun with itand was hooked Bye for now, Steve - Original Message - From: "Geoffrey Mackenzie-Kennedy" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Cc: "Elecraft Discussion List" Sent: Tuesday, March 15, 2005 9:43 AM Subject: Re: [Elecraft] rcvr designs prc-2000 USES DIRECT CONVERSION! 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: <[EMAIL PROTECTED]> To: 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. ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com -- No virus found in this incoming message. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.7.2 - Release Date: 11/03/2005 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] rcvr designs prc-2000 USES DIRECT CONVERSION!
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: <[EMAIL PROTECTED]> To: 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. ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] rcvr designs prc-2000 USES DIRECT CONVERSION!
Some have doubted the K2's RCVR. ""It is only single conversion"" My radiois quad conversion! Check this out, My friend KA4KOE purchased a military field rig. The PRC-2000 is current issue in some places that do not use encrytion. 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. INSTEAD OF XTAL FILTERS, STAGES OF ACTIVE OP AMPS AND AUDIO COILS AND CAPS. OK AUDIO DSP IS USED GREATLY! THE RECEIVER IS VERY HOT. HE WORKS DX WELL. THE PRC-2000 IS ALSO 15-20W SSB. I THINK DX OFF IS NEEDED TO SEE WHICH RADIO IS BETTER! pHIL IS ALL FOR IT. PERHAPS WHEN THE WX IS BETTER, IT WILL BE BATTLE OF THE MANPACK RIGS! ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
