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Re: [CQ-Contest] Handicap For Dirty Rigs

To: cq-contest@contesting.com
Subject: Re: [CQ-Contest] Handicap For Dirty Rigs
From: Tom Osborne <w7why@frontier.com>
Date: Tue, 21 Oct 2014 09:47:24 -0700
List-post: <cq-contest@contesting.com">mailto:cq-contest@contesting.com>
I would think that my old TS-450 must be pretty clean because it seems like just about every RTTY contest I get in, I can be CQ'ing and someone will move in right next to me, inside my 250 cycle passband. I figure it must be someone with a new 'state of the art' rig that can screw their passband down to about 150 cycles and then crowd right in next to me and totally QRM me, while not even knowing I'm there.

Sometimes I just wish there was somewhere I could set mine wide enough to get their attention.

Maybe what we need is some organization to set up a 'cash for dirty rigs' like they did with the 'cash for clunkers' program. I'd be glad to swap my TS-450 for a K-3 :-) 73
Tom W7WHY



On 10/20/2014 10:43 PM, Jim Brown wrote:
On 10/20/2014 2:05 PM, Stuart Phillips wrote:
The FCC publishes required levels of operation for several aspects of radio performance but is silent on matters like phase noise etc beyond using phrases like “commonly accepted engineering practice”.

Hi Stu,

As I wrote in TXNoise.pdf,

"FCC Rules 97.307 (a) No amateur station transmission shall occupy more bandwidth than necessary for the information rate and emission type being transmitted, in accordance with good amateur practice. Figure 12 clearly shows that Yaesu and Icom transceivers are using 3 times more bandwidth than Kenwood and 5 times more than Elecraft. As I read the Rules, this puts anyone using them in violation of 97.307 (a)."

Follow my logic. Elecraft, with their K3, have defined "good amateur practice" with respect to CW. Kenwood's TS590S, less than half the cost of a K3, is next best, and the modern ICOM and Yeasu rigs are much worse. I've seen data from Flex for their 6xxx-series rigs putting them in a class with the K3 for cleanliness, but these data have not been verified by ARRL. In simple terms, today's ICOM and Yeasu rigs are in violation because they use MUCH more than the minimum bandwidth needed for transmission. 97.307 (b) and 97.307 (c) expand upon that standard.

As I see it (and as principal author of all AES Standards on EMC, I have used similar wording), "good amateur practice" with respect to occupied bandwidth was specifically written into the Rules to not tie the hands of innovative designers and allow the State of the Art to advance. Wayne Burdick, Elecraft chief engineer, showed many (all?) of his cards in an Appendix to my report. There is no magic there, simply good, innovative engineering. The methods are available to all.

For years, we were taught that CW bandwidth was related to CW speed, which is a total falsehood -- CW bandwidth is solely a function of rise and fall waveforms, distortion in RF stages, including the output, and phase noise.

73, Jim K9YC

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