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On 10/8/2020 10:43 PM, JR wrote:
> K9YC published a paper purporting to document and quantify transmitter > noise figures - which belies the claim and ultimately validates what the > ARRL Lab told me - namely neither rig is a problem. ARRL Lab engineers are not active in contesting, hence are unlikely to see these problems. My "paper" you referenced is a re-plotting of ARRL Lab data for all rigs on the same scale, and at scales large enough to clearly see differences. It is THEIR DATA, not mine. Not a problem? Yaesu rigs used to be pretty clean on SSB; current vintage Yaesu rigs are VERY dirty on SSB, occupying three times the bandwidth of a clean SSB signal. W4TV, a retired broadcast engineer, traced the cause down to their method of doing ALC. I became aware of this when trying to work next to one of these dirty stations on the band; the P3SVGA display clearly showed the IMD-caused splatter on both sides of the station's intended signal. The splatter extended more than 2 kHz below his USB suppressed carrier frequency, and almost than 5 kHz above it. A clean SSB signal (not ESSB) signal is about 2.7 kHz wide. After this first experience, I observed a lot of signals like this, and asked some of them what rig they were using. It was nearly always a Yaesu. Those that were not were splattering because they were overdriving their amp. This is NOT parochialism, it's solid engineering, which is my expertise. What's yours? 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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On 2020-10-09 12:38 PM, Jim Brown wrote:
> W4TV, a retired broadcast engineer, > traced the cause down to their method of doing ALC. I can't claim credit for that ... the information was originally identified by W8JI in Yaesu rigs as far back as the FT1000D and FT1000MP (and other Yaesu transceivers of that era). Not only do Yaesu derive their ALC based on overdrive of the final amplifiers, they have excess gain in both their TX IF and ALC loop which only makes matters worse (as anyone who is familiar with the design of servo control circuits will understand). One can make a noticeable improvement in TX IMD in Yaesu transceivers by reducing the TX IF gain (if one knows how to access the factory alignment menu) on each band to the minimum necessary to reach full output. Reducing the IF gain also reduces "overshoot" and helps with the key clicks but - alas - it does nothing about the phase noise issues. 73, ... Joe, W4TV On 2020-10-09 12:38 PM, Jim Brown wrote: > On 10/8/2020 10:43 PM, JR wrote: >> K9YC published a paper purporting to document and quantify transmitter >> noise figures - which belies the claim and ultimately validates what >> the ARRL Lab told me - namely neither rig is a problem. > > ARRL Lab engineers are not active in contesting, hence are unlikely to > see these problems. My "paper" you referenced is a re-plotting of ARRL > Lab data for all rigs on the same scale, and at scales large enough to > clearly see differences. It is THEIR DATA, not mine. > > Not a problem? Yaesu rigs used to be pretty clean on SSB; current > vintage Yaesu rigs are VERY dirty on SSB, occupying three times the > bandwidth of a clean SSB signal. W4TV, a retired broadcast engineer, > traced the cause down to their method of doing ALC. I became aware of > this when trying to work next to one of these dirty stations on the > band; the P3SVGA display clearly showed the IMD-caused splatter on both > sides of the station's intended signal. The splatter extended more than > 2 kHz below his USB suppressed carrier frequency, and almost than 5 kHz > above it. A clean SSB signal (not ESSB) signal is about 2.7 kHz wide. > > After this first experience, I observed a lot of signals like this, and > asked some of them what rig they were using. It was nearly always a > Yaesu. Those that were not were splattering because they were > overdriving their amp. > > This is NOT parochialism, it's solid engineering, which is my expertise. > What's yours? > > 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by Conrad PA5Y
A neighbor who lives just 300 yards away purchased and now operates an
IC-7300. When he operates 40m CW, the phase noise occurs across the entire 40m band on my K3 with the upgraded synthesizer. You could never use an IC-7300 for Field Day on the same band with other radios. OTOH, we had three K3's (prior to the upgraded synthesizer on 20m simultaneously. We only knew the others were active if we tuned to within 20 kHz or so of them. I was the the SSB team captain and had no problem on 20m as long as we didn't get "near" the GOTA station when it was on the same band. This was with the same physical distance I know face the IC-7300. Another IC-7300 over a mile away is very broad (20-30 kHz) when operated on 40m SSB. I often hear splatter 40 kHz up the band! While I tell people the IC-7300 is a great package for the price, I also tell them not to use it with big antennas or physically near other radios. Fortunately, I have no Yaesu HF rigs in active use in the neighborhood although I see their dirty signals in many contests. A used K3S is quite a bargain today! 73, Bill, K8TE -- Sent from: http://elecraft.365791.n2.nabble.com/ ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by Lou W0FK
"ARRL Lab engineers are not active in contesting,..."
Meh. Suggesting the ARRL Lab is ignorant about real world contesting is incredible. They are plenty smart, have their own stations, and do NOT live in a technological vacuum. If it was a problem, they would know it. "It is THEIR DATA, not mine." Exactly. You concede my point. You present no evidence or proof of your own, and concede the available data fails to prove the problem. "Yaesu rigs used to be pretty clean on SSB; current vintage Yaesu rigs are VERY dirty ... occupying three times the bandwidth of a clean SSB signal" Pshaw. You exaggerate. Three times normal bandwidth is more than 8.5 MHz. If ALL Yaesu signals really are that wide, everyone would know it, and even the least expensive SDR dongle would easily show it. The boys in the ARRL Lab would be well aware of it, and besides, it makes no sense to say "current vintage" - as "current" and "vintage" are essentially opposites. Bottom line: I gave you the home run pitch, challenging you to proffer hard evidence of your unsubstantiated, anecdotal claim. Instead, your generalizing rebuttal and brandishing credentials is weak as water. AS for MY experience, while I am not an engineer, I am reasonably well informed and made my millions cross-examining self-proclaimed experts lacking sufficient evidence. As this is clearly OT, I will retire before wearing out my welcome, especially considering you have made my point for me! Happy days, and good DX to all. K8JHR ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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And with that, let's end this thread in the interest of keeping tempers
down and relieving email overload for everyone. Also, please always keep discussions cordial, just as you would sitting across from friends at dinner. 73, Eric List moderator, when I'm awake.. *elecraft.com <http://elecraft.com>* ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by K8TE
Years ago one of my students in my license classes came up with what he
thought was a great idea. We had been discussing the difficulty many hams have in finding places to live that allowed antennas. He thought it would be a great idea to start up a development just for hams, so there would be no restrictions in the deeds against antennas. I had to tell him that the last person I want living next door to me is another ham. Which of course led to another discussion. On Fri, Oct 9, 2020, 20:20 K8TE <[hidden email]> wrote: > A neighbor who lives just 300 yards away purchased and now operates an > IC-7300. When he operates 40m CW, the phase noise occurs across the entire > 40m band on my K3 with the upgraded synthesizer. You could never use an > IC-7300 for Field Day on the same band with other radios. > > OTOH, we had three K3's (prior to the upgraded synthesizer on 20m > simultaneously. We only knew the others were active if we tuned to within > 20 kHz or so of them. I was the the SSB team captain and had no problem on > 20m as long as we didn't get "near" the GOTA station when it was on the > same > band. This was with the same physical distance I know face the IC-7300. > > Another IC-7300 over a mile away is very broad (20-30 kHz) when operated on > 40m SSB. I often hear splatter 40 kHz up the band! While I tell people > the > IC-7300 is a great package for the price, I also tell them not to use it > with big antennas or physically near other radios. Fortunately, I have no > Yaesu HF rigs in active use in the neighborhood although I see their dirty > signals in many contests. > > A used K3S is quite a bargain today! > > 73, Bill, K8TE > > > > -- > Sent from: http://elecraft.365791.n2.nabble.com/ > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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