[Premium-Rx] A Policy Question

[Larry Gadallah]

Hello All:

The questions Vic is raising are exactly what I was wondering about. I'm 
afraid that I might have started a flame-war based on some of the responses 
I've seen, but perhaps, given the relentless march of technology, we need to 
examine some questions like these. When the day comes that I can go down to 
Radio Shack and buy some nice Fourier transformers off the shelf and string 
them together to build a radio that performs better than today's W-J and 
Harris gear, is it premium? Or does premium mean "some undisclosed branch of 
the U.S. Government paid a premium for this equipment", regardless of it's 
characteristics?

I also have to admit that what started this question in my head is what I 
read about the performance of some current software defined radios. It used 
to be that they did not have sufficient SFDR to compete with "analog" 
radios, but thanks to some clever design techniques and improvements in ADC 
technology, now they are beginning to meet and surpass the performance of 
radios we consider premium today. Now what?

My best idea for qualifying a premium RX is to come up with a set of "black 
box" performance parameters, and if the box meets them, it is a premium RX, 
regardless of it's price or technology. I'm thinking of things like:

SFDR > 100 dB
IP3 > +15 dBm
MDS < -140 dBm
Ultimate rejection > 90 dB
Shape Factor < 1.1
Noise Figure < 10 dB (for HF and below)

If these numbers were chosen carefully, we could include all or most of what 
we currently classify as premium RX, and automatically deal with anything 
new that comes along.

Speaking of boat anchors, that definition keeps moving too. This weekend, I 
was shocked to discover that my Drake R7 has joined that group since 
sometime in the past five years, Drake quit selling parts and/or servicing 
it. Now to keep it running I need the same sort of guru that makes R-390s 
run...

73s,

On 9/18/05, Vic/Johanna Culver <viculver at verizon.net> wrote:
> 
> *Larry -- I've just returned from a week at Cape Cod -- no computers, no 
> radios, pure vacation! But during the week I've had this recurring thought: 
> What ABOUT software radios? ARE they 'premium?' What would MAKE one premium? 
> What are the defining characteristics of a radio (e.g., my PCR-1000 with 
> TalkPCR software run on a hot laptop) and could it ever be made 'premium' by 
> adding software? And, a related question, how much 'hardware' is really 
> needed for a premium RX -- would my MFJ sound-card interface couple with 
> some exotic (and presently unknown) software to MAKE a real hot radio? 
> Couldn't one define -- in software -- the characteristic that would be most 
> critical for each specific application in a software radio, i.e., 
> sensitivity, selectivity, frequency range to make it 'forever young?'*
> ** 
> *Maybe this is a topic for a special (different) list? Do you suppose any 
> of the boat-anchor crowd (me included) would sit still for an extended 
> discussion (if there IS any extended discussion) on this topic? Or is it 
> really a non-issue, one of those unguarded thought-trains that get 
> mis-routed during extended vacation periods when one does not have any 
> grounding to keep one on the 'straight and narrow?!' *
> ** 
> *I'm picking my way through a weeks accumulated e-mail this morning! Good 
> to be back! Vic*
>  
> -----Original Message-----
> *From:* premium-rx-bounces at ml.skirrow.org [mailto:
> premium-rx-bounces at ml.skirrow.org]*On Behalf Of *Larry Gadallah
> *Sent:* Friday, September 16, 2005 4:28 PM
> *To:* premium-rx at ml.skirrow.org
> *Subject:* [Premium-Rx] A Policy Question
> 
> Oh learned founders of Premium-RX:
> 
> What with the advent of all sorts of geekish-whizbang software radios like 
> the SDR-1000 <http://www.flex-radio.com/index.htm>, 
> SDR-14 <http://www.rfspace.com/sdr14.html>, and doubtless many others to 
> come a question arises: Do any of these qualify as a premium RX?
> 
> What if you upgrade the software? Does it then become possible to do a 
> non-premium->premium upgrade? Can we define some guidelines to differentiate 
> a consumer-grade SDR from a premium SDR? How about the sample rate, or maybe 
> the bits/sample?
> 
> 73,
> -- 
> Larry Gadallah,
> lgadallah AT gmail DOT com 
> 
> 


-- 
Larry Gadallah,
lgadallah AT gmail DOT com
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