[Elecraft] Tuner Loss question
I have lots of data in the loss to be expected in Coax or Open wire when running at higher SWR into a multiband antenna - however, I do NOT have any real world data on the losses to be expected in a tuner system at higher SWR. So: Are there any numbers available on what additional losses my Elecraft K3 (SN 5283) antenna tuner will experience when the SWR is high - say about 5:1 or higher when feeding a multiband antenna with 50 Ohm coax on 20 meters? Should I expect another 3 dB down in signal strength during receive - and also Transmit? Or are the losses higher or lower then that? Also, are the losses frequency dependent (like on coax) or are they the same across the bands. Thanks for any available data. Jobst AC0LP __ 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
Re: [Elecraft] Tuner Loss question
Why do you need to know the loss of the tuner? Put a power meter after the tuner and see what your rig is putting out. Is this the type of chart you are looking for?http://www.packetradio.com/pdfzips/SWRvsPowerNwatts.pdf It is not really the tuner that is causing the loss. It is more the feed line. You can test this by using an external tuner and placing a watt meter both in front and behind the tuner and see what kind of loss you are getting. Yes the tuner will have loss, but relatively negligible. 73 - Tom - wa4ta Date: Tue, 11 Feb 2014 11:47:19 -0600 From: jvand...@gmail.com To: elecraft@mailman.qth.net Subject: [Elecraft] Tuner Loss question I have lots of data in the loss to be expected in Coax or Open wire when running at higher SWR into a multiband antenna - however, I do NOT have any real world data on the losses to be expected in a tuner system at higher SWR. So: Are there any numbers available on what additional losses my Elecraft K3 (SN 5283) antenna tuner will experience when the SWR is high - say about 5:1 or higher when feeding a multiband antenna with 50 Ohm coax on 20 meters? Should I expect another 3 dB down in signal strength during receive - and also Transmit? Or are the losses higher or lower then that? Also, are the losses frequency dependent (like on coax) or are they the same across the bands. Thanks for any available data. Jobst AC0LP __ 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 __ 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
Re: [Elecraft] Tuner Loss question
Sorry, but the chart is showing mismatch loss. When we use a tuner, we don't suffer mismatch loss; we suffer tuner losses, which despite the claim(s), can be appreciable. N7WS On 2/11/2014 2:36 PM, tom armour wrote: Why do you need to know the loss of the tuner? Put a power meter after the tuner and see what your rig is putting out. Is this the type of chart you are looking for?http://www.packetradio.com/pdfzips/SWRvsPowerNwatts.pdf It is not really the tuner that is causing the loss. It is more the feed line. You can test this by using an external tuner and placing a watt meter both in front and behind the tuner and see what kind of loss you are getting. Yes the tuner will have loss, but relatively negligible. 73 - Tom - wa4ta Date: Tue, 11 Feb 2014 11:47:19 -0600 From: jvand...@gmail.com To: elecraft@mailman.qth.net Subject: [Elecraft] Tuner Loss question I have lots of data in the loss to be expected in Coax or Open wire when running at higher SWR into a multiband antenna - however, I do NOT have any real world data on the losses to be expected in a tuner system at higher SWR. So: Are there any numbers available on what additional losses my Elecraft K3 (SN 5283) antenna tuner will experience when the SWR is high - say about 5:1 or higher when feeding a multiband antenna with 50 Ohm coax on 20 meters? Should I expect another 3 dB down in signal strength during receive - and also Transmit? Or are the losses higher or lower then that? Also, are the losses frequency dependent (like on coax) or are they the same across the bands. Thanks for any available data. Jobst AC0LP __ 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
Re: [Elecraft] Tuner Loss question
Check out the ARRL antenna tuner reviews. They all have loss measurements at up to 10:1 SWR for resistive loads. There are two Elecraft ARRL tuner reviews: KAT100 and KAT500. Phil – AD5X __ 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
Re: [Elecraft] Tuner Loss question
I'd recommend trying Dean Straw's (N6BV) excellent Transmission Line for Windows (TLW), packaged with recent editions of the ARRL Antenna book. You can make estimates of component Q and the tool estimates tuner losses for various mismatches for different tuner configurations (L versus Pi versus ...). This is a modeling, not a measurement tool. Phil, AD5X has included tuner loss information in his recent ATU review articles in QST. Maybe there's something on his site of interest. http://www.ad5x.com See particularly http://www.ad5x.com/images/Presentations/Remote%20Tuners.PDF for a description of his measurement technique for tuner loss measurement. 73 de Dick, K6KR -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Wes (N7WS) Sent: Tuesday, February 11, 2014 1:54 PM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] Tuner Loss question Sorry, but the chart is showing mismatch loss. When we use a tuner, we don't suffer mismatch loss; we suffer tuner losses, which despite the claim(s), can be appreciable. N7WS On 2/11/2014 2:36 PM, tom armour wrote: Why do you need to know the loss of the tuner? Put a power meter after the tuner and see what your rig is putting out. Is this the type of chart you are looking for?http://www.packetradio.com/pdfzips/SWRvsPowerNwatts.pdf It is not really the tuner that is causing the loss. It is more the feed line. You can test this by using an external tuner and placing a watt meter both in front and behind the tuner and see what kind of loss you are getting. Yes the tuner will have loss, but relatively negligible. 73 - Tom - wa4ta Date: Tue, 11 Feb 2014 11:47:19 -0600 From: jvand...@gmail.com To: elecraft@mailman.qth.net Subject: [Elecraft] Tuner Loss question I have lots of data in the loss to be expected in Coax or Open wire when running at higher SWR into a multiband antenna - however, I do NOT have any real world data on the losses to be expected in a tuner system at higher SWR. So: Are there any numbers available on what additional losses my Elecraft K3 (SN 5283) antenna tuner will experience when the SWR is high - say about 5:1 or higher when feeding a multiband antenna with 50 Ohm coax on 20 meters? Should I expect another 3 dB down in signal strength during receive - and also Transmit? Or are the losses higher or lower then that? Also, are the losses frequency dependent (like on coax) or are they the same across the bands. Thanks for any available data. Jobst AC0LP __ 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 __ 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
Re: [Elecraft] Tuner Loss question
You would need to know the unloaded Q of the capacitor(s) and Inductor(s) in the circuit when a match is obtained and the complex impedance (not the SWR) of the load to calculate the total loss. More than likely, it will be highly frequency dependent. N7WS. On 2/11/2014 10:47 AM, Jobst Vandrey wrote: I have lots of data in the loss to be expected in Coax or Open wire when running at higher SWR into a multiband antenna - however, I do NOT have any real world data on the losses to be expected in a tuner system at higher SWR. So: Are there any numbers available on what additional losses my Elecraft K3 (SN 5283) antenna tuner will experience when the SWR is high - say about 5:1 or higher when feeding a multiband antenna with 50 Ohm coax on 20 meters? Should I expect another 3 dB down in signal strength during receive - and also Transmit? Or are the losses higher or lower then that? Also, are the losses frequency dependent (like on coax) or are they the same across the bands. Thanks for any available data. Jobst AC0LP __ 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
Re: [Elecraft] Tuner Loss question
On 2/11/2014 9:47 AM, Jobst Vandrey wrote: I have lots of data in the loss to be expected in Coax or Open wire when running at higher SWR into a multiband antenna - however, I do NOT have any real world data on the losses to be expected in a tuner system at higher SWR. Obtain some sheet syrofoam and an indoor-outdoor remote reading thermometer. Build a box from the styrofoam, enclose the tuner inside it with the remote temp sensor and seal the box up. Record the temperature. Fire up your TX into the tuner feeding the load of choice and let the temperature stabilize. Be sure and ID every 10 mins. Meanwhile, calculate the mass of the gas inside the box from its dimensions, the barometric pressure when you sealed up the box, and the Ideal Gas Law [PV=nRT]. Once the temperature stabilizes, you can calculate how much of your TX energy went into heat inside the box. The rest went up the coax. Calculate the loss from L[dB]=10*log[Ph/Po] where Ph = power lost to heat and Po = TX power. So: Are there any numbers available on what additional losses my Elecraft K3 (SN 5283) antenna tuner will experience when the SWR is high - say about 5:1 or higher when feeding a multiband antenna with 50 Ohm coax on 20 meters? Should I expect another 3 dB down in signal strength during receive - and also Transmit? Or are the losses higher or lower then that? Also, are the losses frequency dependent (like on coax) or are they the same across the bands. Seriously, the best way is to find a technical review of the tuner by someone with all the appropriate test equipment. Intrinsically, every tuner has loss that depends on many factors such as the Q of the inductors, the L/C ratios required to match a given load, the complex impedance presented to the tuner by the load, and the current phase of the moon. However, it is very difficult to measure power in non-resistive situations and the odds that the loads presented by your multiband antenna are all resistive is right behind the odds you are pregnant with twins. OK, I made up the part about the moon. I seem to remember a QST series on tuner losses a few years ago, don't know if the KAT3 was one of the ones tested. In reality, it is what it is and if you found the losses to be high at some combination, there's not much you can do about it save re-design your antenna system [or get a different tuner]. 73, Fred K6DGW - Northern California Contest Club - CU in the 2014 Cal QSO Party 4-5 Oct 2014 - www.cqp.org PS: I strongly urge the List Lurkers to get a little chuckle out of the imperfect physics in the first graf and resist the urge to correct my rendition. While I did, in 1959, manage to measure with pretty good accuracy the efficiency of a 10KW FM Class C PA using real physics very similar to my rendition above, I left out a lot in the tuner example. __ 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
