Re: [Elecraft] k3 SWR readings seem generous
Just a dumb question: How do you insert the external SWR meter on the same node as the K3 internal SWR bridge? I don't find an easy solution for my own comparisons. HNY and 73 QRO, Rudolf, hb9ari ab2tc wrote: Just for the record, I have excellent agreement between an external (MFJ-949E) SWR/Wattmeter and the indication on the K3, both at excellent SWR and poor ones such as those offered by my G5RVs when the external tuner is bypassed. Poor agreement here should not be considered normal. Jeff Kinzli N6GQ wrote: Mike, I see the same thing. My Autek says my antenna is 2.5:1, the K3 (#476) says 1.2:1 at the same frequency (numbers mentioned were on 40M). snip - AB2TC - Knut ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] k3 SWR readings seem generous
Rudolf, There is no way to do that external to the K3. It would only be possible if one were to dig into the hardware and insert the external wattmeter into the signal path between the KPA3 and the KAT3. Unfortunately, that would require cutting traces inside the K3. 73, Don W3FPR hb9ari wrote: Just a dumb question: How do you insert the external SWR meter on the same node as the K3 internal SWR bridge? I don't find an easy solution for my own comparisons. HNY and 73 QRO, Rudolf, hb9ari ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] k3 SWR readings seem generous
Don, Thank you for the explanations; the difference between external SWR and K3 SWR without ATU should be less then the differences announced ? 73, Rudolf, HB9ARI Don Wilhelm wrote: Rudolf, There is no way to do that external to the K3. It would only be possible if one were to dig into the hardware and insert the external wattmeter into the signal path between the KPA3 and the KAT3. Unfortunately, that would require cutting traces inside the K3. 73, Don W3FPR hb9ari wrote: Just a dumb question: How do you insert the external SWR meter on the same node as the K3 internal SWR bridge? I don't find an easy solution for my own comparisons. HNY and 73 QRO, Rudolf, hb9ari ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] k3 SWR readings seem generous
Mike, I see the same thing. My Autek says my antenna is 2.5:1, the K3 (#476) says 1.2:1 at the same frequency (numbers mentioned were on 40M). My Palstar SWR meter pretty much agrees with the Autek. -Jeff N6GQ On Thu, Jan 1, 2009 at 17:47, Mike Scott m...@paxsen.com wrote: I have been working on antennas today and have a puzzle. I am finding that the K3 SWR indications are unbelievable generous. With my 40M inverted V fed with RG8X (50 ohm) coax I see that the K3 seems generous in the SWR indication on tune with ATU bypassed. I have noticed a slight change in SWR with K3 power setting so the following was taken with K3 tune power set to 100 watts. If I set it to 10 watts the discrepancy is greater... SWR SWR SWR Freq. K3 VA1 Daiwa 7.00 MHz 1.3 1.922.0 7.05 MHz 1.2 1.921.9 7.1 MHz 1.2 1.981.95 7.15 MHz 1.3 2.262.1 7.2 MHz 1.9 2.602.3 7.25 MHz 1.5 2.882.6 7.3 MHz 1.6 3.322.7 The Daiwa is the CN-101L cross needle meter. The VA1 is the Autek Rx Vector antenna analyzer. The VA1 does not have a tuned input so it is possible that it can be fooled by local broadcast stations. I don't suspect this issue here as there aren't any close by broadcast stations that I am aware of. The Daiwa and the VA1 tend to agree pretty well anyway. The K3 measurements are the outliers. This antenna on a Tenna Dipper shows minimal SWR at 7.040 MHz, just where I tuned it a few years ago. The LED does not extinguish indicating higher than 1:1 SWR at the minimum. If you look at the numbers, I guess I don't believe the K3, Do you think my antenna is below 1.6 to 1 across the entire 40M band? So now on to 20M dipole fed with RG58 (50 Ohm Coax)... The Tenna Dipper fully extinguishes at 13.805 MHz indicating that my antenna is bit too long but is close to 1:1 at that frequency. FreqK3 VA1 Daiwa 13.81 -- 1.12-- 14.0 MHz1.11.241.31 14.1 MHz1.11.301.70 14.2 MHz1.11.551.85 14.3 MHz1.21.691.85 RG58 may have some losses on this band so perhaps all of the SWR indications are generous, some more than others. The dipole is a low one and probably isn't 72 ohms at the feed point. Mike Scott - AE6WA Tarzana, CA (DM04 / near LA) K3-100 #508/ KX1 #1311 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] k3 SWR readings seem generous
Just for the record, I have excellent agreement between an external (MFJ-949E) SWR/Wattmeter and the indication on the K3, both at excellent SWR and poor ones such as those offered by my G5RVs when the external tuner is bypassed. Poor agreement here should not be considered normal. Jeff Kinzli N6GQ wrote: Mike, I see the same thing. My Autek says my antenna is 2.5:1, the K3 (#476) says 1.2:1 at the same frequency (numbers mentioned were on 40M). snip - AB2TC - Knut -- View this message in context: http://n2.nabble.com/k3-SWR-readings-seem-generous-tp2100497p2139102.html Sent from the Elecraft mailing list archive at Nabble.com. ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: Re: [Elecraft] k3 SWR readings seem generous
Brett, this is something I would love to see in all rigs and amplifiers, but then I'm prejudiced;-) 73, Larry N8LP One thing I think would be really slick is to see a path in which someone can insert a watt meter such as the LP-100 into the chain between the output and the antenna tuner where it belongs. I really like all of the flexibility that the RX ANT path affords... Would be really neat to be able to see something like that on the way out. ~Brett (KC7OTG) -- View this message in context: http://n2.nabble.com/k3-SWR-readings-seem-generous-tp2100497p2106697.html Sent from the Elecraft mailing list archive at Nabble.com. ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] k3 SWR readings seem generous
This thread came at the right time. I have just finished re-calibrating my LP-100A. I did this after having used the unit for 6 months, however the calibration was very close to the original settings. Then I thought that I would check my K3 SWR indication. The results are not as good as I would expect. I set the K3 with a tune power of 10W, representing the level of power one might use to adjust an ATU. The measurements I made were using 2 x 8 inch lengths of RG8U from the K3 into the LP-100A coupler, and then from the coupler into the dummy load. The dummy load is a precision 100W one which I measured with a VNA and has a VSWR of 1.03 from 1 to 30 Mhz. To simulate a 2:1 VSWR I used another dummy load (not quite as good) in parallel. The K3 output was from ANT1 using the internal ATU. The ATU was automatically tuned to 1:1 on all bands. The results I got for 2:1 VSWR are as follows:- LP-100 K3 160 1.991.8 80 1.991.8 60 1.991.8 40 1.951.8 30 1.971.6 20 1.971.4 17 1.971.3 15 1.961.2 12 1.961.5 10 1.961.4 As can be seen my K3 SWR indication constantly under reads. However, it really gets bad on 20,17 15. I will be interested in the results of others conducting similar tests. 73 Stewart G3RXQ On Thu, 1 Jan 2009 17:47:04 -0800, Mike Scott wrote: I have been working on antennas today and have a puzzle. I am finding that the K3 SWR indications are unbelievable generous. With my 40M inverted V fed with RG8X (50 ohm) coax I see that the K3 seems generous in the SWR indication on tune with ATU bypassed. I have noticed a slight change in SWR with K3 power setting so the following was taken with K3 tune power set to 100 watts. If I set it to 10 watts the discrepancy is greater... SWR SWR SWR Freq. K3 VA1 Daiwa 7.00 MHz 1.3 1.922.0 7.05 MHz 1.2 1.921.9 7.1 MHz 1.2 1.981.95 7.15 MHz 1.3 2.262.1 7.2 MHz 1.9 2.602.3 7.25 MHz 1.5 2.882.6 7.3 MHz 1.6 3.322.7 The Daiwa is the CN-101L cross needle meter. The VA1 is the Autek Rx Vector antenna analyzer. The VA1 does not have a tuned input so it is possible that it can be fooled by local broadcast stations. I don't suspect this issue here as there aren't any close by broadcast stations that I am aware of. The Daiwa and the VA1 tend to agree pretty well anyway. The K3 measurements are the outliers. This antenna on a Tenna Dipper shows minimal SWR at 7.040 MHz, just where I tuned it a few years ago. The LED does not extinguish indicating higher than 1:1 SWR at the minimum. If you look at the numbers, I guess I don't believe the K3, Do you think my antenna is below 1.6 to 1 across the entire 40M band? So now on to 20M dipole fed with RG58 (50 Ohm Coax)... The Tenna Dipper fully extinguishes at 13.805 MHz indicating that my antenna is bit too long but is close to 1:1 at that frequency. FreqK3 VA1 Daiwa 13.81 -- 1.12-- 14.0 MHz1.11.241.31 14.1 MHz1.11.301.70 14.2 MHz1.11.551.85 14.3 MHz1.21.691.85 RG58 may have some losses on this band so perhaps all of the SWR indications are generous, some more than others. The dipole is a low one and probably isn't 72 ohms at the feed point. Mike Scott - AE6WA Tarzana, CA (DM04 / near LA) K3-100 #508/ KX1 #1311 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] k3 SWR readings seem generous
However, the Gap SWR is around the 2.3:1 range when the K3 (or PW-1 tuner) reads about 1.5:1 or less. I then realized it was showing me the real SWR, not the tuned SWR. I think I am correct in this assumption. John, your understanding is correct unless the K3 ATU is in bypass mode which it was for my tests. The K3 then should be measuring the feed line SWR because there is no tuner in the circuit. Also I used tune mode which shows the digital readout of SWR, not the number of bars on the SWR readout. So try it with the K3 tuner bypassed and see what you get. Mike Scott - AE6WA Tarzana, CA (DM04 / near LA) K3-100 #508/ KX1 #1311 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] k3 SWR readings seem generous
I don't think so. The K3 tuner is in bypass. The LP-100A is next in line, followed by the tuner (no amp yet) followed by the fan dipole. The tuner is showing the tuned SWR. The LP-100A sees only the tuned SWR and the K3 tuner is off so it should see the same thing that the LP-100A sees. The LP-100A and the tuner generally agree (the LP-100A is digital and the tuner uses crossed-needles, but it's close). The K3 is consistently lower. 73, Michael / N6MEF -Original Message- From: John Gaynard [mailto:jgayn...@columbus.rr.com] Sent: Thursday, January 01, 2009 11:24 PM To: 'Michael E Fox (N6MEF)'; elecraft@mailman.qth.net Subject: RE: [Elecraft] k3 SWR readings seem generous Isn't the LP100A giving you the actual SWR, not the tuned SWR since the LP100A is getting current samples from the feedline to the antenna and is independent of the K3 tuner. The K3 tuner is making the K3 see 50 ohms. The LP100 is telling you the actual SWR that exists prior to the K3 tuning it to the 50 ohm. I have the LP100 using it with a SteppIR BiggIR vertical and also a Gap Voyager vertical for 160m and 80m. The LP100 reads around 1.04:1 on the SteppIR on 40m as does the K3 (shows 1 bar), which is close to what my old Diamond meter use to read. However, the Gap SWR is around the 2.3:1 range when the K3 (or PW-1 tuner) reads about 1.5:1 or less. I then realized it was showing me the real SWR, not the tuned SWR. I think I am correct in this assumption. John K8WDN -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Michael E Fox (N6MEF) Sent: Friday, January 02, 2009 1:18 AM To: elecraft@mailman.qth.net Subject: RE: [Elecraft] k3 SWR readings seem generous I noticed the same thing. My factory-assembled K3 is reading 1.0 SWR while my LP-100A and tuner both agree on about 1.4-1.5. Michael - N6MEF -- Message: 45 Date: Thu, 1 Jan 2009 17:47:04 -0800 From: Mike Scott m...@paxsen.com Subject: [Elecraft] k3 SWR readings seem generous To: Elecraft@mailman.qth.net Message-ID: 7a956b0039b848bd89a04d31855c4...@dbqj5v71 Content-Type: text/plain; charset=us-ascii I have been working on antennas today and have a puzzle. I am finding that the K3 SWR indications are unbelievable generous. With my 40M inverted V fed with RG8X (50 ohm) coax I see that the K3 seems generous in the SWR indication on tune with ATU bypassed. I have noticed a slight change in SWR with K3 power setting so the following was taken with K3 tune power set to 100 watts. If I set it to 10 watts the discrepancy is greater... SWR SWR SWR Freq. K3 VA1 Daiwa 7.00 MHz 1.3 1.922.0 7.05 MHz 1.2 1.921.9 7.1 MHz 1.2 1.981.95 7.15 MHz 1.3 2.262.1 7.2 MHz 1.9 2.602.3 7.25 MHz 1.5 2.882.6 7.3 MHz 1.6 3.322.7 The Daiwa is the CN-101L cross needle meter. The VA1 is the Autek Rx Vector antenna analyzer. The VA1 does not have a tuned input so it is possible that it can be fooled by local broadcast stations. I don't suspect this issue here as there aren't any close by broadcast stations that I am aware of. The Daiwa and the VA1 tend to agree pretty well anyway. The K3 measurements are the outliers. This antenna on a Tenna Dipper shows minimal SWR at 7.040 MHz, just where I tuned it a few years ago. The LED does not extinguish indicating higher than 1:1 SWR at the minimum. If you look at the numbers, I guess I don't believe the K3, Do you think my antenna is below 1.6 to 1 across the entire 40M band? So now on to 20M dipole fed with RG58 (50 Ohm Coax)... The Tenna Dipper fully extinguishes at 13.805 MHz indicating that my antenna is bit too long but is close to 1:1 at that frequency. FreqK3 VA1 Daiwa 13.81 -- 1.12-- 14.0 MHz1.11.241.31 14.1 MHz1.11.301.70 14.2 MHz1.11.551.85 14.3 MHz1.21.691.85 RG58 may have some losses on this band so perhaps all of the SWR indications are generous, some more than others. The dipole is a low one and probably isn't 72 ohms at the feed point. Mike Scott - AE6WA Tarzana, CA (DM04 / near LA) K3-100 #508/ KX1 #1311 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] k3 SWR readings seem generous
I have been working on antennas today and have a puzzle. I am finding that the K3 SWR indications are unbelievable generous. With my 40M inverted V fed with RG8X (50 ohm) coax I see that the K3 seems generous in the SWR indication on tune with ATU bypassed. I have noticed a slight change in SWR with K3 power setting so the following was taken with K3 tune power set to 100 watts. If I set it to 10 watts the discrepancy is greater... SWR SWR SWR Freq. K3 VA1 Daiwa 7.00 MHz 1.3 1.922.0 7.05 MHz 1.2 1.921.9 7.1 MHz 1.2 1.981.95 7.15 MHz 1.3 2.262.1 7.2 MHz 1.9 2.602.3 7.25 MHz 1.5 2.882.6 7.3 MHz 1.6 3.322.7 The Daiwa is the CN-101L cross needle meter. The VA1 is the Autek Rx Vector antenna analyzer. The VA1 does not have a tuned input so it is possible that it can be fooled by local broadcast stations. I don't suspect this issue here as there aren't any close by broadcast stations that I am aware of. The Daiwa and the VA1 tend to agree pretty well anyway. The K3 measurements are the outliers. This antenna on a Tenna Dipper shows minimal SWR at 7.040 MHz, just where I tuned it a few years ago. The LED does not extinguish indicating higher than 1:1 SWR at the minimum. If you look at the numbers, I guess I don't believe the K3, Do you think my antenna is below 1.6 to 1 across the entire 40M band? So now on to 20M dipole fed with RG58 (50 Ohm Coax)... The Tenna Dipper fully extinguishes at 13.805 MHz indicating that my antenna is bit too long but is close to 1:1 at that frequency. FreqK3 VA1 Daiwa 13.81 -- 1.12-- 14.0 MHz1.11.241.31 14.1 MHz1.11.301.70 14.2 MHz1.11.551.85 14.3 MHz1.21.691.85 RG58 may have some losses on this band so perhaps all of the SWR indications are generous, some more than others. The dipole is a low one and probably isn't 72 ohms at the feed point. Mike Scott - AE6WA Tarzana, CA (DM04 / near LA) K3-100 #508/ KX1 #1311 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] k3 SWR readings seem generous
Mike, I have to accept your observations, but must ask - have you calibrated the K3 wattmeter? Neglecting to do that can cause the SWR readings to be off by a fair amount. That being said, consider the purpose of the K3 having an SWR indication at all - that is to determine the minimum SWR during a TUNE cycle. The *minimum* SWR is the important parameter to indicate the best tuning point rather than any absolute SWR reading. Long ago when using manual tuners, my elmer told me to simply tune for the lowest reflected power possible, and that was the correct tuning point. The KAT3 tuner algorithm does the same thing - it seeks the minimum reflected power - the absolute SWR is not important, although it may be of interest. Even so, the K3 SWR indication on your K3 does seem to be lower than it should be. Again, if you have not done the Wattmeter Calibration, that would be a step in the right direction. 73, Don W3FPR Mike Scott wrote: I have been working on antennas today and have a puzzle. I am finding that the K3 SWR indications are unbelievable generous. With my 40M inverted V fed with RG8X (50 ohm) coax I see that the K3 seems generous in the SWR indication on tune with ATU bypassed. I have noticed a slight change in SWR with K3 power setting so the following was taken with K3 tune power set to 100 watts. If I set it to 10 watts the discrepancy is greater... SWR SWR SWR Freq. K3 VA1 Daiwa 7.00 MHz 1.3 1.922.0 7.05 MHz 1.2 1.921.9 7.1 MHz 1.2 1.981.95 7.15 MHz 1.3 2.262.1 7.2 MHz 1.9 2.602.3 7.25 MHz 1.5 2.882.6 7.3 MHz 1.6 3.322.7 The Daiwa is the CN-101L cross needle meter. The VA1 is the Autek Rx Vector antenna analyzer. The VA1 does not have a tuned input so it is possible that it can be fooled by local broadcast stations. I don't suspect this issue here as there aren't any close by broadcast stations that I am aware of. The Daiwa and the VA1 tend to agree pretty well anyway. The K3 measurements are the outliers. This antenna on a Tenna Dipper shows minimal SWR at 7.040 MHz, just where I tuned it a few years ago. The LED does not extinguish indicating higher than 1:1 SWR at the minimum. If you look at the numbers, I guess I don't believe the K3, Do you think my antenna is below 1.6 to 1 across the entire 40M band? So now on to 20M dipole fed with RG58 (50 Ohm Coax)... The Tenna Dipper fully extinguishes at 13.805 MHz indicating that my antenna is bit too long but is close to 1:1 at that frequency. FreqK3 VA1 Daiwa 13.81 -- 1.12-- 14.0 MHz1.11.241.31 14.1 MHz1.11.301.70 14.2 MHz1.11.551.85 14.3 MHz1.21.691.85 RG58 may have some losses on this band so perhaps all of the SWR indications are generous, some more than others. The dipole is a low one and probably isn't 72 ohms at the feed point. ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] k3 SWR readings seem generous
I noticed the same thing. My factory-assembled K3 is reading 1.0 SWR while my LP-100A and tuner both agree on about 1.4-1.5. Michael - N6MEF -- Message: 45 Date: Thu, 1 Jan 2009 17:47:04 -0800 From: Mike Scott m...@paxsen.com Subject: [Elecraft] k3 SWR readings seem generous To: Elecraft@mailman.qth.net Message-ID: 7a956b0039b848bd89a04d31855c4...@dbqj5v71 Content-Type: text/plain; charset=us-ascii I have been working on antennas today and have a puzzle. I am finding that the K3 SWR indications are unbelievable generous. With my 40M inverted V fed with RG8X (50 ohm) coax I see that the K3 seems generous in the SWR indication on tune with ATU bypassed. I have noticed a slight change in SWR with K3 power setting so the following was taken with K3 tune power set to 100 watts. If I set it to 10 watts the discrepancy is greater... SWR SWR SWR Freq. K3 VA1 Daiwa 7.00 MHz 1.3 1.922.0 7.05 MHz 1.2 1.921.9 7.1 MHz 1.2 1.981.95 7.15 MHz 1.3 2.262.1 7.2 MHz 1.9 2.602.3 7.25 MHz 1.5 2.882.6 7.3 MHz 1.6 3.322.7 The Daiwa is the CN-101L cross needle meter. The VA1 is the Autek Rx Vector antenna analyzer. The VA1 does not have a tuned input so it is possible that it can be fooled by local broadcast stations. I don't suspect this issue here as there aren't any close by broadcast stations that I am aware of. The Daiwa and the VA1 tend to agree pretty well anyway. The K3 measurements are the outliers. This antenna on a Tenna Dipper shows minimal SWR at 7.040 MHz, just where I tuned it a few years ago. The LED does not extinguish indicating higher than 1:1 SWR at the minimum. If you look at the numbers, I guess I don't believe the K3, Do you think my antenna is below 1.6 to 1 across the entire 40M band? So now on to 20M dipole fed with RG58 (50 Ohm Coax)... The Tenna Dipper fully extinguishes at 13.805 MHz indicating that my antenna is bit too long but is close to 1:1 at that frequency. FreqK3 VA1 Daiwa 13.81 -- 1.12-- 14.0 MHz1.11.241.31 14.1 MHz1.11.301.70 14.2 MHz1.11.551.85 14.3 MHz1.21.691.85 RG58 may have some losses on this band so perhaps all of the SWR indications are generous, some more than others. The dipole is a low one and probably isn't 72 ohms at the feed point. Mike Scott - AE6WA Tarzana, CA (DM04 / near LA) K3-100 #508/ KX1 #1311 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] k3 SWR readings seem generous
Isn't the LP100A giving you the actual SWR, not the tuned SWR since the LP100A is getting current samples from the feedline to the antenna and is independent of the K3 tuner. The K3 tuner is making the K3 see 50 ohms. The LP100 is telling you the actual SWR that exists prior to the K3 tuning it to the 50 ohm. I have the LP100 using it with a SteppIR BiggIR vertical and also a Gap Voyager vertical for 160m and 80m. The LP100 reads around 1.04:1 on the SteppIR on 40m as does the K3 (shows 1 bar), which is close to what my old Diamond meter use to read. However, the Gap SWR is around the 2.3:1 range when the K3 (or PW-1 tuner) reads about 1.5:1 or less. I then realized it was showing me the real SWR, not the tuned SWR. I think I am correct in this assumption. John K8WDN -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Michael E Fox (N6MEF) Sent: Friday, January 02, 2009 1:18 AM To: elecraft@mailman.qth.net Subject: RE: [Elecraft] k3 SWR readings seem generous I noticed the same thing. My factory-assembled K3 is reading 1.0 SWR while my LP-100A and tuner both agree on about 1.4-1.5. Michael - N6MEF -- Message: 45 Date: Thu, 1 Jan 2009 17:47:04 -0800 From: Mike Scott m...@paxsen.com Subject: [Elecraft] k3 SWR readings seem generous To: Elecraft@mailman.qth.net Message-ID: 7a956b0039b848bd89a04d31855c4...@dbqj5v71 Content-Type: text/plain; charset=us-ascii I have been working on antennas today and have a puzzle. I am finding that the K3 SWR indications are unbelievable generous. With my 40M inverted V fed with RG8X (50 ohm) coax I see that the K3 seems generous in the SWR indication on tune with ATU bypassed. I have noticed a slight change in SWR with K3 power setting so the following was taken with K3 tune power set to 100 watts. If I set it to 10 watts the discrepancy is greater... SWR SWR SWR Freq. K3 VA1 Daiwa 7.00 MHz 1.3 1.922.0 7.05 MHz 1.2 1.921.9 7.1 MHz 1.2 1.981.95 7.15 MHz 1.3 2.262.1 7.2 MHz 1.9 2.602.3 7.25 MHz 1.5 2.882.6 7.3 MHz 1.6 3.322.7 The Daiwa is the CN-101L cross needle meter. The VA1 is the Autek Rx Vector antenna analyzer. The VA1 does not have a tuned input so it is possible that it can be fooled by local broadcast stations. I don't suspect this issue here as there aren't any close by broadcast stations that I am aware of. The Daiwa and the VA1 tend to agree pretty well anyway. The K3 measurements are the outliers. This antenna on a Tenna Dipper shows minimal SWR at 7.040 MHz, just where I tuned it a few years ago. The LED does not extinguish indicating higher than 1:1 SWR at the minimum. If you look at the numbers, I guess I don't believe the K3, Do you think my antenna is below 1.6 to 1 across the entire 40M band? So now on to 20M dipole fed with RG58 (50 Ohm Coax)... The Tenna Dipper fully extinguishes at 13.805 MHz indicating that my antenna is bit too long but is close to 1:1 at that frequency. FreqK3 VA1 Daiwa 13.81 -- 1.12-- 14.0 MHz1.11.241.31 14.1 MHz1.11.301.70 14.2 MHz1.11.551.85 14.3 MHz1.21.691.85 RG58 may have some losses on this band so perhaps all of the SWR indications are generous, some more than others. The dipole is a low one and probably isn't 72 ohms at the feed point. Mike Scott - AE6WA Tarzana, CA (DM04 / near LA) K3-100 #508/ KX1 #1311 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] k3 SWR readings seem generous
I forgot to mention. I do not use the ATU on my K3 on 40m since I have the SteppIR BiggIR vertical, and the K3 SWR reading shows only 1 bar which tells me it is seeing 1:1 SWR which is close to the LPA100 reading of 1.04:1. The LP100 just shows the unvarnished truth sometimes about the actual antenna resonance. It is a great tool. John K8WDN -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of John Gaynard Sent: Friday, January 02, 2009 2:24 AM To: 'Michael E Fox (N6MEF)'; elecraft@mailman.qth.net Subject: RE: [Elecraft] k3 SWR readings seem generous Isn't the LP100A giving you the actual SWR, not the tuned SWR since the LP100A is getting current samples from the feedline to the antenna and is independent of the K3 tuner. The K3 tuner is making the K3 see 50 ohms. The LP100 is telling you the actual SWR that exists prior to the K3 tuning it to the 50 ohm. I have the LP100 using it with a SteppIR BiggIR vertical and also a Gap Voyager vertical for 160m and 80m. The LP100 reads around 1.04:1 on the SteppIR on 40m as does the K3 (shows 1 bar), which is close to what my old Diamond meter use to read. However, the Gap SWR is around the 2.3:1 range when the K3 (or PW-1 tuner) reads about 1.5:1 or less. I then realized it was showing me the real SWR, not the tuned SWR. I think I am correct in this assumption. John K8WDN -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Michael E Fox (N6MEF) Sent: Friday, January 02, 2009 1:18 AM To: elecraft@mailman.qth.net Subject: RE: [Elecraft] k3 SWR readings seem generous I noticed the same thing. My factory-assembled K3 is reading 1.0 SWR while my LP-100A and tuner both agree on about 1.4-1.5. Michael - N6MEF -- Message: 45 Date: Thu, 1 Jan 2009 17:47:04 -0800 From: Mike Scott m...@paxsen.com Subject: [Elecraft] k3 SWR readings seem generous To: Elecraft@mailman.qth.net Message-ID: 7a956b0039b848bd89a04d31855c4...@dbqj5v71 Content-Type: text/plain; charset=us-ascii I have been working on antennas today and have a puzzle. I am finding that the K3 SWR indications are unbelievable generous. With my 40M inverted V fed with RG8X (50 ohm) coax I see that the K3 seems generous in the SWR indication on tune with ATU bypassed. I have noticed a slight change in SWR with K3 power setting so the following was taken with K3 tune power set to 100 watts. If I set it to 10 watts the discrepancy is greater... SWR SWR SWR Freq. K3 VA1 Daiwa 7.00 MHz 1.3 1.922.0 7.05 MHz 1.2 1.921.9 7.1 MHz 1.2 1.981.95 7.15 MHz 1.3 2.262.1 7.2 MHz 1.9 2.602.3 7.25 MHz 1.5 2.882.6 7.3 MHz 1.6 3.322.7 The Daiwa is the CN-101L cross needle meter. The VA1 is the Autek Rx Vector antenna analyzer. The VA1 does not have a tuned input so it is possible that it can be fooled by local broadcast stations. I don't suspect this issue here as there aren't any close by broadcast stations that I am aware of. The Daiwa and the VA1 tend to agree pretty well anyway. The K3 measurements are the outliers. This antenna on a Tenna Dipper shows minimal SWR at 7.040 MHz, just where I tuned it a few years ago. The LED does not extinguish indicating higher than 1:1 SWR at the minimum. If you look at the numbers, I guess I don't believe the K3, Do you think my antenna is below 1.6 to 1 across the entire 40M band? So now on to 20M dipole fed with RG58 (50 Ohm Coax)... The Tenna Dipper fully extinguishes at 13.805 MHz indicating that my antenna is bit too long but is close to 1:1 at that frequency. FreqK3 VA1 Daiwa 13.81 -- 1.12-- 14.0 MHz1.11.241.31 14.1 MHz1.11.301.70 14.2 MHz1.11.551.85 14.3 MHz1.21.691.85 RG58 may have some losses on this band so perhaps all of the SWR indications are generous, some more than others. The dipole is a low one and probably isn't 72 ohms at the feed point. Mike Scott - AE6WA Tarzana, CA (DM04 / near LA) K3-100 #508/ KX1 #1311 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft
