[Elecraft] Wattmeter for K3s Calibration
Would the LP-100A meet the accuracy/precision requirements to do the power cals outlined in the K3s Manual? If not, please supply recommendation for one that will do the job adequately. Thanks! -- __ Clay Autery, KG5LKV MONTAC Enterprises (318) 518-1389 __ 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] Wattmeter for K3s Calibration
Clay, An LP-100A calibrated to N8LP's NIST traceable standards is about the best you are going to find at a price that is palatable to most hams. Used in conjunction with a precision 50 ohm dummy load, the calibration results will be better than most other wattmeters. The LP-100A. I have one at the workbench that serves as the secondary standard for all my other wattmeters. With NIST tracable calibration it's accuracy is typically 3% of the reading. The Elecraft W2 is also good for that task and should be sufficiently accurate with its +/- 0.5dB Accuracy specification. 73, Don W3FPR On 4/26/2016 9:49 PM, Clay Autery wrote: Would the LP-100A meet the accuracy/precision requirements to do the power cals outlined in the K3s Manual? If not, please supply recommendation for one that will do the job adequately. __ 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] Wattmeter for K3s Calibration
For the Transmitter Gain calibration, all you need is a decent dummy load. The LP-100A is not a dummy load. My 20-year old inexpensive MFJ dummy load does a good job for that. (But note it has never been abused, such as running power into it until it gets hot or smells.) A well designed dummy load will have very little reactance from stray capacitance or inductance. That leaves only the value of the resistive element, which you can check with your DMM. It's the resistive element that is most susceptible to damage from overheating it, just like any other resistor. For calibrating the wattmeter in your K3S beyond the factory setting, whatever makes you happy is perfect. There is no operational or performance advantage to "improving" the factory settings. The LP-100A claims 3% power display accuracy which is much better than most (if the claims are true). For example, the ARRL lab is quoted in their manual saying "They specify their measurement error for power as +/- 5%, and for PEP power, +/- 8%." Note the +/- meaning the power error may vary by 10% for constant carrier and 16% PEP. Those are much more typical values for good, even lab quality power measurement equipment. 73, Ron AC7AC -Original Message- From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Clay Autery Sent: Tuesday, April 26, 2016 6:50 PM To: Elecraft Reflector Subject: [Elecraft] Wattmeter for K3s Calibration Would the LP-100A meet the accuracy/precision requirements to do the power cals outlined in the K3s Manual? If not, please supply recommendation for one that will do the job adequately. Thanks! -- __ Clay Autery, KG5LKV MONTAC Enterprises (318) 518-1389 __ 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 r...@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] Wattmeter for K3s Calibration
Not referring to the XMTR Gain cal... talking about the Tune PWR cals... I have a decent dummy load I think... It's a Navy DA-412/U (50-Ohm, 600W continuous, 900 W for 15 minutes). It has no measurable reactance 0-30 MHz, and less than 2 Ohm up to 400MHz... at least according to the analyzer I had access to. Will likely get a precision 50-Ohm dummy load for cal purposes since it only needs to be 5 and 50 W for the cals... I'm a bit OCD on certain things... like eliminating variables on basic cals so I don't have to worry about my end during ops. __ Clay Autery, KG5LKV MONTAC Enterprises (318) 518-1389 On 4/26/2016 9:57 PM, Ron D'Eau Claire wrote: > For the Transmitter Gain calibration, all you need is a decent dummy load. > The LP-100A is not a dummy load. My 20-year old inexpensive MFJ dummy load > does a good job for that. (But note it has never been abused, such as > running power into it until it gets hot or smells.) A well designed dummy > load will have very little reactance from stray capacitance or inductance. > That leaves only the value of the resistive element, which you can check > with your DMM. It's the resistive element that is most susceptible to damage > from overheating it, just like any other resistor. > > For calibrating the wattmeter in your K3S beyond the factory setting, > whatever makes you happy is perfect. There is no operational or performance > advantage to "improving" the factory settings. The LP-100A claims 3% power > display accuracy which is much better than most (if the claims are true). > For example, the ARRL lab is quoted in their manual saying "They specify > their measurement error for power as +/- 5%, and for PEP power, +/- 8%." > Note the +/- meaning the power error may vary by 10% for constant carrier > and 16% PEP. Those are much more typical values for good, even lab quality > power measurement equipment. > > 73, Ron AC7AC > > -Original Message- > From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Clay > Autery > Sent: Tuesday, April 26, 2016 6:50 PM > To: Elecraft Reflector > Subject: [Elecraft] Wattmeter for K3s Calibration > > Would the LP-100A meet the accuracy/precision requirements to do the power > cals outlined in the K3s Manual? > > If not, please supply recommendation for one that will do the job > adequately. > > Thanks! > > -- > __ > Clay Autery, KG5LKV > MONTAC Enterprises > (318) 518-1389 > > __ > 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 r...@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] Wattmeter for K3s Calibration
Clay, I see nothing in the K3 manual about Tune PWR calibration. There is the wattmeter calibration for which you need a good 50 ohm dummy load and a wattmeter that you can trust. The other is the TX Gain Calibration which needs only a good 50 ohm dummy load. If those are both done, then your TUNE PWR setting will be accurate. 73, Don W3FPR On 4/26/2016 11:15 PM, Clay Autery wrote: Not referring to the XMTR Gain cal... talking about the Tune PWR cals... __ 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] Wattmeter for K3s Calibration
On Tue,4/26/2016 6:49 PM, Clay Autery wrote: Would the LP-100A meet the accuracy/precision requirements to do the power cals outlined in the K3s Manual? I own one, with two couplers for my SO2R station. It's a fine product, and at least some years ago, was used at Elecraft for production testing. Pro quality dummy loads are among the things I buy at ham flea markets. 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] Wattmeter for K3s Calibration
K3S Manual, Revision A, May 26, 2015, page 52, left column, half way down... "If desired, the [TUNE] power readings can be calibrated, This must be done at 5.0 W, 50 W (K3s/100 only), and 1.00 mW. IF you read this page, you find that the procedure requires a 50-W capable dummy load (minimum), an "accurate" wattmeter, and for the "Milliwatt-meter Calibration", "an accurate RF voltmeter". __ Clay Autery, KG5LKV MONTAC Enterprises (318) 518-1389 On 4/26/2016 10:47 PM, Don Wilhelm wrote: > Clay, > > I see nothing in the K3 manual about Tune PWR calibration. > There is the wattmeter calibration for which you need a good 50 ohm > dummy load and a wattmeter that you can trust. > The other is the TX Gain Calibration which needs only a good 50 ohm > dummy load. > > If those are both done, then your TUNE PWR setting will be accurate. > > 73, > Don W3FPR > > On 4/26/2016 11:15 PM, Clay Autery wrote: >> Not referring to the XMTR Gain cal... talking about the Tune PWR >> cals... >> >> > __ 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] Wattmeter for K3s Calibration
Thanks, Jim. :) __ Clay Autery, KG5LKV MONTAC Enterprises (318) 518-1389 On 4/27/2016 12:59 AM, Jim Brown wrote: > On Tue,4/26/2016 6:49 PM, Clay Autery wrote: >> Would the LP-100A meet the accuracy/precision requirements to do the >> power cals outlined in the K3s Manual? > > I own one, with two couplers for my SO2R station. It's a fine product, > and at least some years ago, was used at Elecraft for production > testing. Pro quality dummy loads are among the things I buy at ham > flea markets. > > 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 caut...@montac.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] Wattmeter for K3s Calibration
I found a Cavalier King Charles figure stamp, a "This Envelope Sealed with Dog Slobber" stamp and a "I'd Rather be Flying" stamp, several Ink Pads and a re-inking roller in Black. That is only in one drawer. Willis 'Cookie' Cooke, From: Ron D'Eau Claire To: 'Clay Autery' ; 'Elecraft Reflector' Sent: Tuesday, April 26, 2016 9:57 PM Subject: Re: [Elecraft] Wattmeter for K3s Calibration For the Transmitter Gain calibration, all you need is a decent dummy load. The LP-100A is not a dummy load. My 20-year old inexpensive MFJ dummy load does a good job for that. (But note it has never been abused, such as running power into it until it gets hot or smells.) A well designed dummy load will have very little reactance from stray capacitance or inductance. That leaves only the value of the resistive element, which you can check with your DMM. It's the resistive element that is most susceptible to damage from overheating it, just like any other resistor. For calibrating the wattmeter in your K3S beyond the factory setting, whatever makes you happy is perfect. There is no operational or performance advantage to "improving" the factory settings. The LP-100A claims 3% power display accuracy which is much better than most (if the claims are true). For example, the ARRL lab is quoted in their manual saying "They specify their measurement error for power as +/- 5%, and for PEP power, +/- 8%." Note the +/- meaning the power error may vary by 10% for constant carrier and 16% PEP. Those are much more typical values for good, even lab quality power measurement equipment. 73, Ron AC7AC -Original Message- From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Clay Autery Sent: Tuesday, April 26, 2016 6:50 PM To: Elecraft Reflector Subject: [Elecraft] Wattmeter for K3s Calibration Would the LP-100A meet the accuracy/precision requirements to do the power cals outlined in the K3s Manual? If not, please supply recommendation for one that will do the job adequately. Thanks! -- __ Clay Autery, KG5LKV MONTAC Enterprises (318) 518-1389 __ 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 r...@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 wrco...@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