There are several problems in judging a “dirty rig”…
“Dirty” by whose standards?
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”.
Hams have a reasonable expectation that their radio complies with the
regulations when they purchase it. But what happens when someone uses a 40
year old radio in a contest? Regulations typically grandfather older products
that continue in use today.
As an example. many of the older radios have poor lower sideband suppression -
often as little as 30 dB - modern radios are much better.
So how is one to assess a penalty on the user of a “dirty” rig that to complied
to the regulations (and likely engineering practice) in effect when the rig was
purchased? Should we add a rule that says (as the originator of this thread
comes close to suggesting) only Elecraft K3 radios built after date X may be
used in the contest? No, I didn’t think so…
Further, if a station with a “clean” rig operates next to a station with a
“dirty” rig, how are you going to measure the contributory effects of one on
the other? How are you going to do this at distance X, 2X, 3X etc where the
signal strengths drop away? Comes close to the first rock principle…
Designing a standard for contest radios is straight forward (though not without
controversy). Compliance can be assessed in a lab - that is clear. IMO,
measuring compliance on a crowded band with mixed contributions to measurement,
coupled with older rigs cannot be done in a manner that would pass peer review.
I’m sure some vendors of modern equipment would LOVE a rule in a contest that
made old radios obsolete by assessing them a huge contest penalty. I’m sure
this email reflector will keel over and croak from the load should a contest
organizer try this. Go on! Some one has to be first! :-)
The issue is real - of that there is no question. BUT… as operators we have a
choice of where we operate on the band. One always has the choice to move -
plus, a good operator with a good radio can pull signals out from the noise
created by the “dirty” rig - yes, it takes time but that’s part of the required
skill level.
ARRL and others like Rob Sherwood, Adam Farson etc help improve the knowledge
of the ham community and in turn that helps incentivize manufacturers to
improve their products. We as hams can also vote with our wallets...
But it still doesn’t address the grandfathered issue of older rigs - and likely
never will.
Lastly, we need to review the agenda of those who might raise this issue in
pursuit of personal vendettas. Beware the hidden agenda that might in some
communities be reasonably viewed as harassment and unacceptable behavior in our
modern society.
… and no, I don’t possess one of the radios on the so called “dirty list”. ;-)
Stu K6TU
> On Oct 18, 2014, at 6:06 PM, Randy Thompson K5ZD <k5zd@charter.net> wrote:
>
> It is true that some rigs (depending on how they are operated) can produce
> signals that appear wider than normal. Can you think of a way to express
> this in technical terms rather than using a K3 as a reference. Contesting
> needs to have a dialog around what is the accepted standard for signal width
> or "cleanliness".
>
> What test equipment would some use to evaluate their own signal in the
> shack?
>
> What would be a good test standard for someone listening to capture the
> essence of the signal quality?
>
>
> Randy, K5ZD
>
>> -----Original Message-----
>> From: CQ-Contest [mailto:cq-contest-bounces@contesting.com] On Behalf Of
>> Jim Brown
>> Sent: Sunday, October 12, 2014 4:57 PM
>> To: cq-contest@contesting.com
>> Subject: [CQ-Contest] Handicap For Dirty Rigs
>>
>> In my study of the TX Noise produced by current transceivers, I noted the
>> significant advantage enjoyed by users of dirty rigs by pushing other
>> stations away from their TX frequency, and making it difficult (or
>> impossible) for stations to S&P near them. Consider the lineup of
>> hundreds of NA stations in the 15 kHz 160M JA window, and comparable
>> conditions from east coast to EU. One FTDX5000D burns five K3 channels;
>> one ICOM 7800,7700, 7600, burns three. I run a K3 and a Ten Tec Titan,
>> which is quite clean. I've established a run frequency for JA only to run
>> off by a guy with a dirty power amp 700 Hz away.
>>
>> Competitors using these dirty rigs should pay the price competitively. I
>> propose a scoring penalty of 15% to the users of FTDX5000 and other Yaesu
>> rigs in that family (study ARRL data to understand why that's valid), and
>> 10% to users of IC7800, 7700, 7600. KE1B, who uses a 7600 to drive a
>> solid state amp, wipes out 10 kHz of whatever band he is on for me on CW,
>> more on SSB. I'm not a WRTC competitor, but K6XX is, and his dirty TX
>> hurts Bob worse than me. By contrast, Bob and I, with K3s and tube amps,
>> can work 500 Hz apart and barely know the other is there. And Bob is
>> three miles closer than KE1B.
>>
>> Is this fair? I contend that with the right to run high power comes the
>> responsibility to produce the CLEANEST signal consistent with the state
>> of the art. K3 has established the state of the art, and preliminary data
>> from the mfr suggest that Flex 6000-series may be as good. Kenwood
>> TS590S is 10 dB worse, at a very modest price. I contend THAT is state of
>> the art, and that ICOM and Yaesu fail to meet it.
>>
>> Yes, I'm saying that users of these dirty rigs need to replace them with
>> cleaner ones. In 2008, I sold a pair of loaded FT1000MPs at significant
>> loss to be replaced by K3s. I did this because I could see from specs
>> that I needed to do that to coexist with my neighbors. Before that, I
>> owned a pair of TS850s and K2s. All sold.
>>
>> And remember -- this is ARRL's data, not mine. :)
>>
>> From my days in the civil rights movement of the '60s and '70s -- "if
>> you're not part of the solution, you're part of the problem!" I've dumped
>> my dirty rigs -- how about YOU?
>>
>> 73, Jim K9YC
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>
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