Re: [K3] [Elecraft] It have to work better!

Don, yes, after replaced the W16 the difference between the main signal and the greatest spur is similar before. But we can see, that quantity of spurs are much less. Here is plots from Line-Out: before replace the W16 : http://forum.cqham.ru/download.php?id=33328 and after replaced the W16

Re: [K3] [Elecraft] It have to work better!

Hi Alex, What is the mod/problem found?? 73, Julius n2wn Alexander Ponomarenko-5 wrote: Hi for all K3-users, Some weeks we searched for the reason of bad K3's sound and high level IMD. We tried to replace resistors on the line-out board. But it is ineffectual. Fortunately, Vlad

Re: [K3] [Elecraft] It have to work better!

Julius Fazekas n2wn wrote: What is the mod/problem found?? Yes Alex, can you please say more about what you found on the RF Board and what the fix was? Congratulations on the success! 73, Barry N1EU -- View this message in context:

Re: [K3] [Elecraft] It have to work better!

Alexander Ponomarenko-5 wrote: Hi for all K3-users, Some weeks we searched for the reason of bad K3's sound and high level IMD. We tried to replace resistors on the line-out board. But it is ineffectual. Fortunately, Vlad UN7GZ has found out the problem. Vlad has analysed the

Re: [K3] [Elecraft] It have to work better!

Priwet Bill, In original K3 the W16 is monowire (on top of the RF-board), but if we will analyze the scheme, we can see that W16 must be in the screen. The W16 are near non screen-shielded BP-Filters, and we can see second RX-channel on my first web-link:

Re: [K3] [Elecraft] It have to work better!

Alexander Ponomarenko-5 wrote: In original K3 the W16 is monowire (on top of the RF-board), but if we will analyze the scheme, we can see that W16 must be in the screen. The W16 are near non screen-shielded BP-Filters, and we can see second RX-channel on my first web-link:

Re: [K3] [Elecraft] It have to work better!

Hi, My spectrum on the line out isn't even as clean as the before picture. In addition to the spur at 12kHz I have spurs at 3.9kHz and 7.8kHz. They, as well as the 12kHz spur are down about 75dB relative to an above AGC threshold single tone. They are independent of mode and passband settings. I

Re: [K3] [Elecraft] It have to work better!

It is the green colored wire beneath the noise blanker board? And you replaced it with a coaxial cable on the bottom side of the RF board, is that right? 73, Drew AF2Z On Mon, 24 Nov 2008 19:25:56 +0200, Alex UR5LAM wrote: Priwet Bill, In original K3 the W16 is monowire (on top of the

Re: [K3] [Elecraft] It have to work better!

Barry N1EU wrote: Alexander Ponomarenko-5 wrote: In original K3 the W16 is monowire (on top of the RF-board), but if we will analyze the scheme, we can see that W16 must be in the screen. The W16 are near non screen-shielded BP-Filters, and we can see second RX-channel on my first web-link:

Re: [K3] [Elecraft] It have to work better!

Yes Drew, it is right. And it is only beginning (W16). 73! Alex UR5LAM drewko wrote: It is the green colored wire beneath the noise blanker board? And you replaced it with a coaxial cable on the bottom side of the RF board, is that right? 73, Drew AF2Z On Mon, 24 Nov 2008 19:25:56 +0200,

Re: [K3] [Elecraft] It have to work better!

Hi Alex, are the both ends of coax shield soldered to GND ? thanks for info, Lexa, OK1DST K3/10 #727 Alexander Ponomarenko napsal(a): Barry N1EU wrote: Alexander Ponomarenko-5 wrote: In original K3 the W16 is monowire (on top of the RF-board), but if we will analyze the scheme, we can

Re: [K3] [Elecraft] It have to work better!

The schematic is in error. It was found that the coax was unnecessary. The levels of signals reported are not audible at greater than 50-60 dB down from normal signals and do not impact our sensitivity spec. 73, Eric WA6HHQ Barry N1EU wrote: Alexander Ponomarenko-5 wrote: In

Re: [K3] [Elecraft] It have to work better!

Hi Lexa, yes both, it's right: http://forum.cqham.ru/download.php?id=32786 73! Alex UR5LAM Alexandr Kobranov wrote: Hi Alex, are the both ends of coax shield soldered to GND ? thanks for info, Lexa, OK1DST K3/10 #727 Alexander Ponomarenko napsal(a): Barry N1EU wrote: Alexander

Re: [K3] [Elecraft] It have to work better!

Hi Eric, may be error in schematic, may be in my head. :) Please look on these new plots: here is plot with s9-level signal from XG1 BEFORE replaced W16: http://forum.cqham.ru/download.php?id=32057 and here is plot with s9-level signal from XG1 AFTER replaced W16:

Re: [K3] [Elecraft] It have to work better!

Alex, From what I see on your plots, the frequencies of the spurs have changed. On the BEFORE plot, I see a main signal at -9dB and the 2 major spurs are -78 dB at 10.4 kHz and another at -77 dB at 12.6 kHz. The difference between the main signal and the greatest spur is 68 dB. On the

Re: [K3] [Elecraft] It have to work better!

Good point Don. Similarly, I noticed in the original post that, while the noise floor in the fixed case was flatter, it was also 10dB higher than the non-modified version, apparently masking the issue, not fixing it. here is plot BEFORE modification (you can see terrible spur near 12kHz)