Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
Chris Johnson elecr...@ozy.us wrote: 1) Is phase noise the measurement of the instability of an DDS? That's one contributing factor. But the DDS signal drives a mixer, and the other input to the mixer may be the larger source of phase noise in transmit mode. 2) How does this impact TX only, and why does it create such an issue to nearby listeners? In the case of the KX3 and Flex radios (e.g. Flex 1500/3000/5000), the limiting factor is probably the transmit D-to-A converter. Its performance is limited by quantization and sampling noise, setting an upper bound on phase noise. The KX3 has an advantage in that its synthesizer uses a DDS-driven PLL, while the Flex radios are DDS only, without a following PLL. But the TX DAC is still a factor in both cases. In a well-designed superhet like the K3, the TX DAC's noise floor affects only the in-band portion of the transmitted signal, i.e. the portion within the I.F. crystal filter passband. The K3 has two crystal filters in series in transmit mode, which results in very high rejection of noise outside the SSB passband (typically 100-3000 Hz). This means that the limiting factor on wideband transmit noise is not the IF injection into the mixer -- it really *is* the synthesizer. The K3's synthesizer is extremely clean at wide offsets (another DDS-driven PLL), and that is why its transmit phase noise is so low. 3) Does phase noise go down if you use a faster master clock? The Flex 6700 uses a 983.04mhz vs a 122.99Mhz clock in the 6300. That is a completely different design (direct digital up/down conversion), which requires very high clock speeds, very expensive ADC and DAC components, and high current drain in receive mode. It can be made clean in transmit and receive modes, although in receive mode this architecture will still have typically 15-20 dB lower blocking dynamic range than a well-designed superhet. None of this is applicable to the KX3, which is obviously intended to be an ultraportable radio with low current drain and low cost. 4) Do low phase noise radios allow in-band use, such as someone on CW on 20M and someone up on voice on 20M? Yes. In general this is only a problem if you have stations in very close proximity. In this situation, the K3 is better than any other radio on the market. This is why the K3 is highly favored for Field Day and DXpeditions. 73, Wayne N6KR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
Thanks Wayne and Alan, for that super detailed info. The radio side of things are still very magical to me! I'm a software guy, not a hardware guy. :) I don't own a K3, but two KX3's for my knob radios. I use a Flex 6700 and 6300 for home use. I'm assuming the 6700's -147 dBc@10kHz, -152 dBc@100kHz phase noise values are pretty good then, if anything higher than -140 dBc is acceptable. Even the 6300 is spec'd at -140 dBc@10kHz. I do agree that my old (and sold) 3000 was messing up the bands during Field Day last year. This year we are using a K3, two 6300's, and a 6700, so I'm hoping for better performance all around. Again, thank you for the info! On Jun 9, 2014, at 9:08 AM, Wayne Burdick n...@elecraft.com wrote: Chris Johnson elecr...@ozy.us wrote: 1) Is phase noise the measurement of the instability of an DDS? That's one contributing factor. But the DDS signal drives a mixer, and the other input to the mixer may be the larger source of phase noise in transmit mode. 2) How does this impact TX only, and why does it create such an issue to nearby listeners? In the case of the KX3 and Flex radios (e.g. Flex 1500/3000/5000), the limiting factor is probably the transmit D-to-A converter. Its performance is limited by quantization and sampling noise, setting an upper bound on phase noise. The KX3 has an advantage in that its synthesizer uses a DDS-driven PLL, while the Flex radios are DDS only, without a following PLL. But the TX DAC is still a factor in both cases. In a well-designed superhet like the K3, the TX DAC's noise floor affects only the in-band portion of the transmitted signal, i.e. the portion within the I.F. crystal filter passband. The K3 has two crystal filters in series in transmit mode, which results in very high rejection of noise outside the SSB passband (typically 100-3000 Hz). This means that the limiting factor on wideband transmit noise is not the IF injection into the mixer -- it really *is* the synthesizer. The K3's synthesizer is extremely clean at wide offsets (another DDS-driven PLL), and that is why its transmit phase noise is so low. 3) Does phase noise go down if you use a faster master clock? The Flex 6700 uses a 983.04mhz vs a 122.99Mhz clock in the 6300. That is a completely different design (direct digital up/down conversion), which requires very high clock speeds, very expensive ADC and DAC components, and high current drain in receive mode. It can be made clean in transmit and receive modes, although in receive mode this architecture will still have typically 15-20 dB lower blocking dynamic range than a well-designed superhet. None of this is applicable to the KX3, which is obviously intended to be an ultraportable radio with low current drain and low cost. 4) Do low phase noise radios allow in-band use, such as someone on CW on 20M and someone up on voice on 20M? Yes. In general this is only a problem if you have stations in very close proximity. In this situation, the K3 is better than any other radio on the market. This is why the K3 is highly favored for Field Day and DXpeditions. 73, Wayne N6KR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
Pardon my ignorance, but can I get some clarification on a few things? 1) Is phase noise the measurement of the instability of an DDS? If so, does this mean a cheap part is being used? Does a GPSDO or a OCXO reduce phase noise? 2) How does this impact TX only, and why does it create such an issue to nearby listeners? 3) Does phase noise go down if you use a faster master clock? The Flex 6700 uses a 983.04mhz vs a 122.99Mhz clock in the 6300. 4) Do low phase noise radios allow in-band use, such as someone on CW on 20M and someone up on voice on 20M? What is considered a low value? Sorry for so many questions, but this is still a very difficult concept for me to grasp. Thanks Chris On Jun 6, 2014, at 8:18 AM, Wayne Burdick n...@elecraft.com wrote: On Jun 6, 2014, at 4:33 AM, Stewart Bryant stew...@g3ysx.org.uk wrote: My understanding is that the KX3 is worse than the K3 on TX phase noise sidebands. Is that what you would expect? No. Both have very, very low transmitted phase noise. 73, Wayne N6KR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to elecr...@ozy.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
On 06/08/2014 09:21 PM, Chris Johnson wrote: Pardon my ignorance, but can I get some clarification on a few things? 1) Is phase noise the measurement of the instability of an DDS? Yes. To oversimplify a bit, if the frequency/phase of the oscillator is varying back and forth at a 20 kHz rate then there will be phase noise at a 20 kHz offset from the carrier. If so, does this mean a cheap part is being used? Not necessarily. Phase noise can creep in at many places in a frequency synthesizer. You have to get the entire design exactly right to have a clean signal that has low phase noise and low spurs at all frequency offsets. Does a GPSDO or a OCXO reduce phase noise? Maybe. Normally it would only improve the phase noise within the loop bandwidth of a PLL-type synthesizer. With a DDS-type oscillator it would depend on whether the phase noise from the clock or the DDS itself dominates (at any given offset). 2) How does this impact TX only, and why does it create such an issue to nearby listeners? If the same local oscillator is used for both the receiver and the transmitter, then the phase noise will be the same. In both cases it causes the oscillator spectrum to spread out. In the transmit case, that can cause interference on nearby frequencies. In a receiver, it causes reciprocal mixing which makes it sound like nearby strong transmitters have excessive phase noise even if they don't. 3) Does phase noise go down if you use a faster master clock? The Flex 6700 uses a 983.04mhz vs a 122.99Mhz clock in the 6300. Maybe. Every time you divide an oscillator's frequency you potentially reduce the phase noise by up to 6 dB per octave (division by 2). However, that only helps if the high-frequency oscillator has good phase noise to begin with and the dividing process introduces no phase noise of its own. 4) Do low phase noise radios allow in-band use, such as someone on CW on 20M and someone up on voice on 20M? That's the goal. Almost all the early synthesized transceivers of 30-40 years ago had horrible phase noise. Hams soon discovered that they were useless in multi-transmitter environments like Field Day. It was a problem both on receive and transmit. People resorted to using old non-synthesized tube rigs like Drake and Collins. What is considered a low value? It's a matter of opinion. The top receivers in Sherwood's chart are on the order of 140-ish dBc/Hz at 10 kHz offset. http://www.sherweng.com/table.html Alan N1AL __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
On 02/04/2014 16:19, Wayne Burdick wrote: The K3 and KX3 both have very low phase noise. It can vary a bit from band to band and from one unit to the next. Sherwood measured one example of each, but typically both measure right around -140 dBc/Hz at 20 kHz. When we designed the K3, we were trying to improve on the phase noise numbers usually found in transceivers with synthesized local oscillators. Typical values were -110 to -120 dBc/Hz, and this definitely impacted stations within close proximity of each other. By using a very high C/L ratio in the K3's VCO, we achieved numbers in the -140 range, and our field testers in close proximity could no longer hear each other at all. This result was corroborated by the Ducie Island DXpedition, the first to use K3s. They told us that they had a 30-m CW station and a 30-m RTTY station both running at the same time within 1 kHz of each other. The KX3 uses a different type of synthesizer, but the result is the same. In this case an on-chip VCO runs at a very high frequency and is then divided down to get to the HF range. 73, Wayne N6KR Wayne My understanding is that the KX3 is worse than the K3 on TX phase noise sidebands. Is that what you would expect? This can be quite critical when choosing between the K(X)3s as a transverter driver in a dense VHF/UHF environment (5 to 10Km separation at 400W to high gain beams) such as you find in the SE of UK. Stewart/G3YSX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
On Jun 6, 2014, at 4:33 AM, Stewart Bryant stew...@g3ysx.org.uk wrote: My understanding is that the KX3 is worse than the K3 on TX phase noise sidebands. Is that what you would expect? No. Both have very, very low transmitted phase noise. 73, Wayne N6KR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] Why is KX3 phase noise so much less than the K3 ?
http://www.sherweng.com/table.html The LO Noise (dBc/Hz): 144 KX3 138 K3 130 R390A 121 FT-1000D 117 ICOM 720A I'm wondering why the KX3 Lo noise is so much better than the K3. The R390A value strange since the first local oscillator is a quartz crystal. I've owned a Icom 720A and own a FT-1000D. Ive never owned a K3, KX3 or a R390A. Larry -- View this message in context: http://elecraft.365791.n2.nabble.com/Why-is-KX3-phase-noise-so-much-less-than-the-K3-tp7586369.html Sent from the Elecraft mailing list archive at Nabble.com. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
Can anyone really hear the difference between any of the top rated rigs (Sherwood list) in the real world (not in a lab)? Bill K-Line __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
Yes, when your neighbours FTDX5000 at 300 metres away spews noise over three adjacent bands. Compounded by idling the FT and making up the power with an amp which only makes the problem worse by another 15dB. Adjacent bands are clear when a Dunestar BPF filter inserted between his FT and amp. My K3 doesn't offer him the same problem. Regards, Mike VP8NO On 02/04/2014 10:25, Bill W2BLC wrote: Can anyone really hear the difference between any of the top rated rigs (Sherwood list) in the real world (not in a lab)? Bill K-Line __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
The FTdx5000 does that in RX mode? Nasty! :-) Phil W7OX On 4/2/14, 7:17 AM, Mike Harris wrote: Yes, when your neighbours FTDX5000 at 300 metres away spews noise over three adjacent bands. Compounded by idling the FT and making up the power with an amp which only makes the problem worse by another 15dB. Adjacent bands are clear when a Dunestar BPF filter inserted between his FT and amp. My K3 doesn't offer him the same problem. Regards, Mike VP8NO On 02/04/2014 10:25, Bill W2BLC wrote: Can anyone really hear the difference between any of the top rated rigs (Sherwood list) in the real world (not in a lab)? Bill K-Line __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
It's easy to demonstrate this. My real-world setting is Field Day, and the example is actually what my team experienced. Take four rigs in a Field Day setting, within 100 yards of each other. Make sure one of them is a K3, and the others are Y/K/I types. On the same band, any of the Y/K/I rigs will create so much wideband [phase] noise on transmit that none of the other rigs are usable on receive. Transmit on the K3 and all the other rigs are usable on receive (same band, mind you). No BPF required in this case. This is very real-world. It's also the reason DXpeditioners use Elecraft products in close proximity with no ill effects. Field Day is just my Regular Joe example of the same thing. Yes, there is a huge difference - not just a statistic for the charts. 73, matt W6NIA On Wed, 02 Apr 2014 09:25:53 -0400, you wrote: Can anyone really hear the difference between any of the top rated rigs (Sherwood list) in the real world (not in a lab)? Bill K-Line __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to mzil...@roadrunner.com Matt Zilmer, W6NIA -- Give me six hours to chop down a tree and I will spend the first four sharpening the axe. -A. Lincoln __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
The K3 and KX3 both have very low phase noise. It can vary a bit from band to band and from one unit to the next. Sherwood measured one example of each, but typically both measure right around -140 dBc/Hz at 20 kHz. When we designed the K3, we were trying to improve on the phase noise numbers usually found in transceivers with synthesized local oscillators. Typical values were -110 to -120 dBc/Hz, and this definitely impacted stations within close proximity of each other. By using a very high C/L ratio in the K3's VCO, we achieved numbers in the -140 range, and our field testers in close proximity could no longer hear each other at all. This result was corroborated by the Ducie Island DXpedition, the first to use K3s. They told us that they had a 30-m CW station and a 30-m RTTY station both running at the same time within 1 kHz of each other. The KX3 uses a different type of synthesizer, but the result is the same. In this case an on-chip VCO runs at a very high frequency and is then divided down to get to the HF range. 73, Wayne N6KR On Apr 2, 2014, at 5:40 AM, Larry Lopez lawlop...@gmail.com wrote: http://www.sherweng.com/table.html The LO Noise (dBc/Hz): 144 KX3 138 K3 130 R390A 121 FT-1000D 117 ICOM 720A I'm wondering why the KX3 Lo noise is so much better than the K3. The R390A value strange since the first local oscillator is a quartz crystal. I've owned a Icom 720A and own a FT-1000D. Ive never owned a K3, KX3 or a R390A. Larry -- View this message in context: http://elecraft.365791.n2.nabble.com/Why-is-KX3-phase-noise-so-much-less-than-the-K3-tp7586369.html Sent from the Elecraft mailing list archive at Nabble.com. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to n...@elecraft.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
Not that I know of, but when it transmits, it wipes out nearby receivers. 73, Don W3FPR On 4/2/2014 10:55 AM, Phil Wheeler wrote: The FTdx5000 does that in RX mode? Nasty! :-) __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
That is why I try to encourage the local Field Day group to use only Elecraft gear. Even though we do not typically operate more than one transceiver on a single band, the YKI types can cause problems on other harmonically related bands. We used to have a Yaesu FT-900 on SSB, and it caused problems. Typically we are class 2A with a GOTA station. 73, Don W3FPR On 4/2/2014 11:06 AM, Matt Zilmer wrote: It's easy to demonstrate this. My real-world setting is Field Day, and the example is actually what my team experienced. Take four rigs in a Field Day setting, within 100 yards of each other. Make sure one of them is a K3, and the others are Y/K/I types. On the same band, any of the Y/K/I rigs will create so much wideband [phase] noise on transmit that none of the other rigs are usable on receive. Transmit on the K3 and all the other rigs are usable on receive (same band, mind you). No BPF required in this case. This is very real-world. It's also the reason DXpeditioners use Elecraft products in close proximity with no ill effects. Field Day is just my Regular Joe example of the same thing. Yes, there is a huge difference - not just a statistic for the charts. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
Like Don said, not in receive, but in transmit, driving an Alpha 9500 to the full 1500 out, a close neighbor (about 5 blocks away) was noticeable on my K3 within 5-10 KHz of his transmit frequency. That said, the FTdx5000 was MUCH cleaner than the FT-1000MP he had prior to obtaining the 5000. The phase noise key clicks from the 1000MP were horrendous but at least his huge signal did not pump the K3's AGC unless he was within my 400Hz filter passband. I could operate the same band and within 3 KHz or so of him after he got the 5000. He, however, had problems with my 500 watt signal overloading his front end if he tried to operate within around 10KHz of me after he got the 5000. Fortunately the entire problem was solved a few months ago when he moved to an inherited farm QTH 20 or so miles from here. W0EB Not that I know of, but when it transmits, it wipes out nearby receivers. 73, Don W3FPR On 4/2/2014 10:55 AM, Phil Wheeler wrote: The FTdx5000 does that in RX mode? Nasty! :-) __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to w...@cox.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
I agree, Matt, and every rig I use now is an Elecraft (K3, KX3, K2, ...). But the question the OP posed was K3 vs. KX3: I'm wondering why the KX3 Lo noise is so much better than the K3 73, Phil W7OX On 4/2/14, 8:06 AM, Matt Zilmer wrote: It's easy to demonstrate this. My real-world setting is Field Day, and the example is actually what my team experienced. Take four rigs in a Field Day setting, within 100 yards of each other. Make sure one of them is a K3, and the others are Y/K/I types. On the same band, any of the Y/K/I rigs will create so much wideband [phase] noise on transmit that none of the other rigs are usable on receive. Transmit on the K3 and all the other rigs are usable on receive (same band, mind you). No BPF required in this case. This is very real-world. It's also the reason DXpeditioners use Elecraft products in close proximity with no ill effects. Field Day is just my Regular Joe example of the same thing. Yes, there is a huge difference - not just a statistic for the charts. 73, matt W6NIA __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
There was some discussion about the effects when on receive as well, I seem to think another manufacturer, not Electraft and not one of the 'big 3' was shown to be quite poor with it's radiated signals even on receive. Or, did I read the lab reports incorrectly? Dave (G0DJA) - Original Message - Sent: Wednesday, April 02, 2014 3:38 PM Subject: Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ? Like Don said, not in receive, but in transmit, driving an Alpha 9500 to the full 1500 out, a close neighbor (about 5 blocks away) was noticeable on my K3 within 5-10 KHz of his transmit frequency. That said, the FTdx5000 was MUCH cleaner than the FT-1000MP he had prior to obtaining the 5000. The phase noise key clicks from the 1000MP were horrendous but at least his huge signal did not pump the K3's AGC unless he was within my 400Hz filter passband. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
You may be thinking of reciprocal mixing, a measure of receiver performance that is impacted by synthesizer phase noise, spurs, etc. Wayne N6KR On Apr 2, 2014, at 8:48 AM, Dave d...@g0dja.co.uk wrote: There was some discussion about the effects when on receive as well, I seem to think another manufacturer, not Electraft and not one of the 'big 3' was shown to be quite poor with it's radiated signals even on receive. Or, did I read the lab reports incorrectly? Dave (G0DJA) - Original Message - Sent: Wednesday, April 02, 2014 3:38 PM Subject: Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ? Like Don said, not in receive, but in transmit, driving an Alpha 9500 to the full 1500 out, a close neighbor (about 5 blocks away) was noticeable on my K3 within 5-10 KHz of his transmit frequency. That said, the FTdx5000 was MUCH cleaner than the FT-1000MP he had prior to obtaining the 5000. The phase noise key clicks from the 1000MP were horrendous but at least his huge signal did not pump the K3's AGC unless he was within my 400Hz filter passband. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to n...@elecraft.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
Phase noise is very important on receive. If your L.O. has a high phase noise content, the phase noise will mix with signals away from the L.O. and bring those signals into your filter bandwidth as noise. This is called reciprocal mixing and is essentially as described below. If you want a radio that yields higher signal to noise ratios, everything being equal, lower the phase noise. 73, Barry K3NDM On 4/2/2014 11:48 AM, Dave wrote: There was some discussion about the effects when on receive as well, I seem to think another manufacturer, not Electraft and not one of the 'big 3' was shown to be quite poor with it's radiated signals even on receive. Or, did I read the lab reports incorrectly? Dave (G0DJA) - Original Message - Sent: Wednesday, April 02, 2014 3:38 PM Subject: Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ? Like Don said, not in receive, but in transmit, driving an Alpha 9500 to the full 1500 out, a close neighbor (about 5 blocks away) was noticeable on my K3 within 5-10 KHz of his transmit frequency. That said, the FTdx5000 was MUCH cleaner than the FT-1000MP he had prior to obtaining the 5000. The phase noise key clicks from the 1000MP were horrendous but at least his huge signal did not pump the K3's AGC unless he was within my 400Hz filter passband. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k3...@comcast.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
I think Bill's question spoke to phase-noise on receive, not transmit. I'm fairly certain all of us are aware of the transmit problem from some transceivers. To Bill's question, I'd say No, I cannot hear the difference when the measured noise is in the -135to -140 range, other noise sources totally mask it for me. 73, Fred K6DGW - Northern California Contest Club - CU in the 2014 Cal QSO Party 4-5 Oct 2014 - www.cqp.org On 4/2/2014 8:06 AM, Matt Zilmer wrote: On the same band, any of the Y/K/I rigs will create so much wideband [phase] noise on transmit that none of the other rigs are usable on receive. Transmit on the K3 and all the other rigs are usable on receive (same band, mind you). No BPF required in this case. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
That's a silly comment. Last time I checked, people nearby a trashy transmitter have to listen as well. They didn't create no smoking rules in public places to protect smokers from their own smoke. Dave AB7E On 4/2/2014 7:55 AM, Phil Wheeler wrote: The FTdx5000 does that in RX mode? Nasty! :-) Phil W7OX On 4/2/14, 7:17 AM, Mike Harris wrote: Yes, when your neighbours FTDX5000 at 300 metres away spews noise over three adjacent bands. Compounded by idling the FT and making up the power with an amp which only makes the problem worse by another 15dB. Adjacent bands are clear when a Dunestar BPF filter inserted between his FT and amp. My K3 doesn't offer him the same problem. Regards, Mike VP8NO On 02/04/2014 10:25, Bill W2BLC wrote: Can anyone really hear the difference between any of the top rated rigs (Sherwood list) in the real world (not in a lab)? Bill K-Line __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to xda...@cis-broadband.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
The KX3 isn't perfect. During SOTA activations, Gary W5ODS and I each use a KX3, with the roofing filter option. He with an end-fed wire, and me usually with an AlexLoop. I can often hear his code (a pink noise sound) even when he is in a band higher in frequency, as well as when I am in a higher band and he the lower. Sometimes turning on RX SHIFT 8kHz knocks it out, sometimes it doesn't. Turning on the attenuator or lowering RF gain doesn't seem to knock it out either. Is that phase noise or another phenom? Don't get me wrong, I do love the KX3. Chip AE5KA __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
Better hope there's no Flex's transmitting too close to your location either. Chas , Bill W2BLC wrote: Can anyone really hear the difference between any of the top rated rigs (Sherwood list) in the real world (not in a lab)? Bill K-Line __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
Did you turn on RX ISO? That is an isolation preamp that reduces LO leakage during receive. That sounds like a different problem that you are hearing, but it is recommended when you are operating a KX3 near other rigs. wunder K6WRU On Apr 2, 2014, at 9:40 AM, Chip Stratton c...@strattonfamily.us wrote: The KX3 isn't perfect. During SOTA activations, Gary W5ODS and I each use a KX3, with the roofing filter option. He with an end-fed wire, and me usually with an AlexLoop. I can often hear his code (a pink noise sound) even when he is in a band higher in frequency, as well as when I am in a higher band and he the lower. Sometimes turning on RX SHIFT 8kHz knocks it out, sometimes it doesn't. Turning on the attenuator or lowering RF gain doesn't seem to knock it out either. Is that phase noise or another phenom? Don't get me wrong, I do love the KX3. Chip AE5KA __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to wun...@wunderwood.org -- Walter Underwood wun...@wunderwood.org __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
Why does the ARRL lab test show the KX3 TX phase noise as about -124 dBc/Hz (Fig 5 of their report) and Sherwood show this as -144 dBc/Hz, both at 10 kHz spacing? That is a huge difference. The ARRL report shows that the KX3 never goes below about -135 dBc/Hz, even 1 MHz away. Is there an update to the ARRL lab test? Did the ARRL miss this one? FWIW, ARRL shows the K3 at about -142 and the FTdx5000 at -135, at 10 kHz spacing. 73 de dave ab9ca/4 On 4/2/14 7:40 AM, Larry Lopez wrote: http://www.sherweng.com/table.html The LO Noise (dBc/Hz): 144 KX3 138 K3 130 R390A 121 FT-1000D 117 ICOM 720A I'm wondering why the KX3 Lo noise is so much better than the K3. The R390A value strange since the first local oscillator is a quartz crystal. I've owned a Icom 720A and own a FT-1000D. Ive never owned a K3, KX3 or a R390A. Larry -- View this message in context: http://elecraft.365791.n2.nabble.com/Why-is-KX3-phase-noise-so-much-less-than-the-K3-tp7586369.html Sent from the Elecraft mailing list archive at Nabble.com. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to ho13d...@gmail.com . __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
Thank you Fred K6DGW - you are correct - I was referring to phase noise on RX. So far as noise from XMIT on other rigs, I have no experience. I live in a rural area and have an extremely low ambient noise level. A noisy RX exposes itself immediately. As I recall, the quietest rig I ever had back in the day was a TenTec Corsair II. However, that was over twenty five years ago and it was analog. Of my recent type equipment, the K3 is the quietest - most likely as quiet as the Corsair was. Just understand, my viewpoint is from the armchair copy side. I do not DX or contest. The K-Line is probably overkill for what I use it for, however, it sure is awfully good at the job (just know your rig and make the appropriate menu adjustments). My original comment/query merely was aimed at the difference in real world use and inside a copper lined lab. Bill K-Line __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
No! And I have them all. My TenTec Eagle hears as good as my FT5K and our beloved K3 and KX3 George, W6GF On Wednesday, April 2, 2014 10:02 AM, Charlie T, K3ICH pin...@erols.com wrote: Better hope there's no Flex's transmitting too close to your location either. Chas , Bill W2BLC wrote: Can anyone really hear the difference between any of the top rated rigs (Sherwood list) in the real world (not in a lab)? Bill K-Line __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to georgefrit...@yahoo.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
First of all, the ARRL is showing (as you note) transmitted phase noise. Rob lists receiver phase noise. Ideally, they should be the same, but are they really? Second, there can be significant test sample variation and variation between phase noise test sets.* Third, phase noise measurements aren't trivial. Witness the dozens of application notes and articles dealing with the subject. ARRL's own Test Procedures Manual states: *NOTE: Composite noise setup is very sensitive to environment noise. Use of common-mode ferrite chokes may be required if test fixture problems are encountered as described in the procedure for this test. In my working career I have seldom seen or made, a phase noise plot that wasn't corrupted by 60Hz spurs, for example. * Rob himself summarizes this on his website: http://www.sherweng.com/images/MeasurementAccuracySampleVariation.pdf And last, but certainly not least, why get bent out of shape over one number. Rob does at once a service and disservice by publishing his charts. They are extremely handy but too many people jump on one number to rate (rank) equipment and totally disregard things like ergonomics (If they didn't the K3 would be at the bottom of the list). He recognizes this in his closing paragraph of the above referenced work. We should pay it more heed. Wes N7WS On 4/2/2014 10:09 AM, dave wrote: Why does the ARRL lab test show the KX3 TX phase noise as about -124 dBc/Hz (Fig 5 of their report) and Sherwood show this as -144 dBc/Hz, both at 10 kHz spacing? That is a huge difference. The ARRL report shows that the KX3 never goes below about -135 dBc/Hz, even 1 MHz away. Is there an update to the ARRL lab test? Did the ARRL miss this one? FWIW, ARRL shows the K3 at about -142 and the FTdx5000 at -135, at 10 kHz spacing. 73 de dave ab9ca/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
The Sherwood list ranking isn’t about how well radios “hear” in general. Under the right conditions, most of the radios on the last (and a whole lot of radios that aren’t) can hear everything our most beloved radio (whatever that is) hears. The list is ranked in order of decreasing narrow spaced (2Khz signal spacing) dynamic range, which is something that makes a difference in extreme conditions. The rankings don’t say a thing at all about MDS, or how the AGC behaves, or internal phase noise, or many other factors (although Sherwood does indicate when phase noise gets to be limiting in the measurements). Radios even close to the bottom of the list can hear everything just fine that a radio at the top of the list can — most of time. It’s those “not most of the time” situations where narrow spaced dynamic range matters that the ranking matters … Grant NQ5T On Apr 2, 2014, at 12:55 PM, george fritkin georgefrit...@yahoo.com wrote: No! And I have them all. My TenTec Eagle hears as good as my FT5K and our beloved K3 and KX3 George, W6GF On Wednesday, April 2, 2014 10:02 AM, Charlie T, K3ICH pin...@erols.com wrote: Better hope there's no Flex's transmitting too close to your location either. Chas , Bill W2BLC wrote: Can anyone really hear the difference between any of the top rated rigs (Sherwood list) in the real world (not in a lab)? Bill K-Line __ __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
Larry, Not knowing much about the R390A, but Sherwood ranks it very low in phase noise. Xtal oscillators are easier to design with low phase noise than synthesizers. This is primarily why later radios have a problem with noise as most use synthesized LO's, and why the old radios with xtal oscillators hear so well. As to why it would matter, phase noise will limit the sensitivity of a receiver. HF sky noise masks most receiver noise issues, but if you are pursuing weak-signal contacts is matters a lot. HF receivers used with transverters on VHF/UHF/mw frequencies are way more sensitive if they have low phase noise, especially due the fact that sky noise drops of very quickly above 6m. Phase noise was one of the prime reasons I chose the K3 for my eme station which detects signals in the -180 dBm level. 73, Ed - I'm wondering why the KX3 Lo noise is so much better than the K3. The R390A value strange since the first local oscillator is a quartz crystal. I've owned a Icom 720A and own a FT-1000D. Ive never owned a K3, KX3 or a R390A. Larry 73, Ed - KL7UW http://www.kl7uw.com Kits made by KL7UW Dubus Mag business: dubus...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
Our field day has been all Elecraft for the last couple of years with mostly K3s and a scattering of K2s. Last year we ran 9A QRP battery + GOTA (+ satellite). We had antennas which allowed us to run CW, SSB and Digital on the same band and had no significant mutual interference. (We work hard to keep our antennas in each others nulls, and being a west coast station, always point them east.) The bigest interference problem was phase noise from another club's operation about 1/2 mile away. They were running 100 watts with I-K-Y gear. Cheers - Bill, AE6JV On 4/2/14 at 8:23 AM, w3...@embarqmail.com (Don Wilhelm) wrote: That is why I try to encourage the local Field Day group to use only Elecraft gear. Even though we do not typically operate more than one transceiver on a single band, the YKI types can cause problems on other harmonically related bands. We used to have a Yaesu FT-900 on SSB, and it caused problems. Typically we are class 2A with a GOTA station. --- Bill Frantz| QRP: So you can talk about | Periwinkle (408)356-8506 | the ones that got away. | 16345 Englewood Ave www.pwpconsult.com | | Los Gatos, CA 95032 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
On 4/2/2014 1:42 PM, Bill Frantz wrote: The bigest interference problem was phase noise from another club's operation about 1/2 mile away. They were running 100 watts with I-K-Y gear. My biggest problem is from a retired east coast lawyer 8 miles from me who runs an ICOM 7600 to a solid state amp. He regularly wipes out 5-10 kHz on CW, twice as much on SSB. 73, Jim K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
I'll try to summarize: lo phase noise is good: it reduces unintended radiation from transmitters. it reduces reciprocal mixing on receiving. surveys during contests are very revealing. The KX3 and K3 have similar very low amounts of phase noise. Unless I want to make a career of it I should stop at this point. Nothing is perfect. thank you very much everyone. larry lopez N2CVS -- View this message in context: http://elecraft.365791.n2.nabble.com/Why-is-KX3-phase-noise-so-much-less-than-the-K3-tp7586369p7586419.html Sent from the Elecraft mailing list archive at Nabble.com. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
