Re: [Elecraft] KPA1500 wattmeter adjustment
I would guess most RF power meters are lucky to be within 5% accuracy of full scale. As a comm tech in the 2-way commercial industry, the Bird43 is pretty much a standard field instrument for measuring power and reflected power (to check SWR on cables, antennas, filters, etc.). If you want higher precision measuring ac voltage across an accurate 50-ohm termination is the better choice. The ac voltmeter is your scope and its accuracy depends on the frequency range its built for. For fairly low power you can get quite accurate RF loads. I keep a couple for doing comparison checks with my Bird (have two of them). Since I do ham radio up to 10-GHz the Bird and most ham SWR meters are useless. I have a surplus HP432A microwave power meter for that. Its not calibrated (recently). I have several directional couplers for measuring reflected power. A couple are rated to nearly 1000w for the 900-MHz mobile phone market. I checked directional and coupling factors using the HP432A at 1296 and those are installed on output of my 600w 1296 amp for continuous monitoring forward and reflected power. I use a small pcb with shottky diode detectors to provide indication on a ma meter. I record the dc voltage derived with RF power measured by the HP432A. Milliammeter is then set with a precision bench PS at the observed voltage from the detector. They will get checked often with one of the Birds for a quick test. The Birds will be calibrated with the HP432A using attenuators to bring level down to 1mw. I only have a 150MHz scope at present so can't really use it for RF calibrations at mw frequencies but the HP432A can be compared at HF or VHF. So probably most hams are not going to send their RF power meters out for calibration. But there probably are 1% who might. Solution would be for them to offer to test meters for other hams at a nominal fee (or even for free) if two-way shipping is paid for. That is done by a few microwave hams for others. 73, Ed - KL7UW __ 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] KPA1500 wattmeter adjustment
If you dig into the QST reviews, you'll find out that the LP100 did not quite meet its spec of 5% accuracy on all bands at all power levels and modes. But then, neither did the LP500 nor the W2. The old Array Solutions Powermaster II came closer than any of those three. it was within 5% everywhere except at 5 watts CW at 50 MHz. http://www.telepostinc.com/Telepost.pdf http://www.telepostinc.com/LP-500_QST_review.pdf The W2 was reviewed in the July 2010 QST. The Array Solutions Powermaster (not the II) was reviewed in the January 2006 QST. 73, -Steve WX2S __ 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] KPA1500 wattmeter adjustment
Having taught in a number of ham crams, I am aware that there are many individual ways of learning. For me, knowing the theory is basic. I know such factoids as E=IR, P=EI, 1 meter is 40 inches (useful for the length of a 2M antenna). Others just memorize the answers. I also have to memorize the answers for questions about the amateur rules. However, guess which technique has a better pass rate. Like Jim, I keep trying to learn more. It is good that there are people like K9YC and K4TAX who can still teach me things. 73 Bill AE6JV > On Feb 6, 2022, at 15:14, Jim Brown wrote: > > Sure, as a teenager 65 years ago I studied/memorized the License Manual, but > have spent the rest of my life studying and learning more, and I'm still > doing it! __ 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] KPA1500 wattmeter adjustment
Unless you are QRP (5 W) or QRO (1.5Kw) what difference a 10% or more calibration error makes?. Our hobby equipment are not laboratory grade instruments. Just curious. 73, Lou KE1F On 2/6/2022 17:09, Bob McGraw wrote: 'Twas said "a man with one watch always knows the time. A man with 3 or 4 watches is never quite sure of the time.". I just recently went through power calibrations on my K3S and my KPA500. All now agree with the power meter reference I used. Also, this was done using a known 50.5 ohm dummy load. On the antennas, even though SWR is indicated 1.1:1, there will be differences due to difference line complex impedance's. 73 Bob, K4TAX On 2/6/2022 9:51 AM, elecraft-requ...@mailman.qth.net wrote: Message: 15 Date: Sat, 5 Feb 2022 14:53:59 -0600 From: Ronnie Hull To: Dick Dievendorff Cc:Elecraft@mailman.qth.net Subject: Re: [Elecraft] KPA1500 wattmeter adjustment Message-ID: Content-Type: text/plain; charset=utf-8 Lucky your that close! My K3, P:, Lp100 and kpa1500 are all wa different. I accept the LPA100 as being correct! Ron W5SUM __ 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 lmecs...@cfl.rr.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] KPA1500 wattmeter adjustment
I don’t think the point was the technical discussion. It was more likely that, as written: > Did we forget about how to use Ohms Law? Seems so. Or perhaps we never > knew to start with. The reasonable interpretation is that the writer implied that some sub-set of the ham population “never knew to start with.” Seems a little on the adversarial tone to the casual observer, but I actually thought it was funny, and was waiting for some pot to call the kettle black. Best from the West. Yours in the quest for zero impedance and minimum entropy, Ed McCann AG6CX Sent from my iPhone > On Feb 6, 2022, at 12:14 PM, Jim Brown wrote: > > On 2/6/2022 11:18 AM, Ronnie Hull wrote: >> One in every crowd… why do we have to throw rocks at each other > > Why must technical discussions be viewed as adversarial? Bob is NOT "throwing > rocks," he is sharing what he's learned over his life as a technical > professional. As a young ham, I benefited immensely from that kind of > sharing, and all my life I've tried to return the favor. > > Bob's assessment of the technical knowledge of many (but certainly not all) > hams is not wrong -- far too many memorized test questions to get a license > and have rarely cracked a book to actually LEARN how stuff works, instead > going with a multitude of urban myths and half-truths. > > Sure, as a teenager 65 years ago I studied/memorized the License Manual, but > have spent the rest of my life studying and learning more, and I'm still > doing it! > > 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 edwmcc...@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] KPA1500 wattmeter adjustment
On 2/6/2022 11:18 AM, Ronnie Hull wrote: One in every crowd… why do we have to throw rocks at each other Why must technical discussions be viewed as adversarial? Bob is NOT "throwing rocks," he is sharing what he's learned over his life as a technical professional. As a young ham, I benefited immensely from that kind of sharing, and all my life I've tried to return the favor. Bob's assessment of the technical knowledge of many (but certainly not all) hams is not wrong -- far too many memorized test questions to get a license and have rarely cracked a book to actually LEARN how stuff works, instead going with a multitude of urban myths and half-truths. Sure, as a teenager 65 years ago I studied/memorized the License Manual, but have spent the rest of my life studying and learning more, and I'm still doing it! 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] KPA1500 wattmeter adjustment
On 2/6/2022 11:14 AM, Bob McGraw wrote: The instrument also costs in the neighborhood of $500+. Have you priced a Bird 43 recently? A new one without an element will set you back about $450, used about $275. Expect to pay $100 - $200 for a new slug, and depending on frequency and power level, we may need several. My drawer includes about 15 of them, all used. Yes, I paid a lot less -- 20 years ago! The Bird is only accurate in a matched 50 ohm line. A standard Bird 43 only reads forward and reverse power, and we must do the math to compute SWR. I still own one that I use as a portable/bench instrument for troubleshooting, or to look at 2M/440 rigs/antennas. I recently gave my spare to a neighbor who lost everything in a wildfire. The LP100A reads complex voltage and current, which the screen screen can be set to display, in addition to SWR, average, peak, and instantaneous power, and is accurate in mismatched lines when fed by a 50 ohm source. The standard coupler is good for up to 3KW from 160M to 54 MHz, and power accuracy is 5% of the reading from 1W to rated power, and over that frequency range. Compared to a Bird, it's a BARGAIN! I own two LP100As, one with two couplers inline with the outputs of the two amps in my HF SO2R contesting station, and a second with a coupler dedicated to the second output of my KPA1500 that feeds my 7-el 6M Yagi. 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] KPA1500 wattmeter adjustment
One in every crowd… why do we have to throw rocks at each other Sent from my iPhone > On Feb 6, 2022, at 1:15 PM, Bob McGraw wrote: > > Power measurements can be accomplished in other ways. One is to use an RF > Amp meter and a known value load. Broadcast stations have done it this way > for years. Hence, 4.4 amps into 50 ohms is 1000 watts. Another way is to > use the voltage across a value of R and calculate power. Thus 223.6 volts > across 50 ohms is 1000 watts. And finally if the voltage and current is > known, then E x I = P. The LP-100 series, as I understand, uses two > methods, one measuring current and one measuring voltage and calculates > power. The instrument also costs in the neighborhood of $500+. > > Most ham meters, including the Bird series are voltage sensing devices and > presume the load to be some value which was used for calibration. Thus if > the meter is in a true 50 ohm circuit, it will most likely be correct within > the percentage of full scale accuracy. However, if the meter was originally > calibrated for 50 ohms and it is in a 20 ohm circuit the error will be > significant. Thus most ham type power meters are "relative reading" > instruments, and not absolute measuring instruments. > > RF Amp meters are relatively easy to verify accuracy. Being thermocouple > devices, one can apply 60 Hz of some value of voltage and a known load and > then determine the accuracy. Again, I = E/R. > > Did we forget about how to use Ohms Law? Seems so. Or perhaps we never > knew to start with. > > 73 > > Bob, K4TAX > > > > >> On 2/6/2022 12:47 PM, Mark Goldberg wrote: >> The only way to really know for sure is to have a NIST traceable calibrated >> wattmeter and have it calibrated on a regular basis. Hams are generally too >> cheap to do that. The LP100 does come calibrated, so that would be my go to >> reference, but I'll bet Hams will hardly ever get the calibration checked >> after purchase. I could not find how much they charge for that service. Even >> that is only calibrated to 5% with 3% typical. So, if you off 5W while >> measuring 100W, who knows, it might be just the calibration error. >> >> 73, >> >> Mark >> W7MLG >> >> On Sun, Feb 6, 2022 at 10:11 AM Bob McGraw wrote: >> >>'Twas said "a man with one watch always knows the time. A man >>with 3 or >>4 watches is never quite sure of the time.". >> >>I just recently went through power calibrations on my K3S and my >>KPA500. All now agree with the power meter reference I used. >>Also, this >>was done using a known 50.5 ohm dummy load. On the antennas, even >>though SWR is indicated 1.1:1, there will be differences due to >>difference line complex impedance's. >> >>73 >> >> Bob, K4TAX >> >> >>On 2/6/2022 9:51 AM, elecraft-requ...@mailman.qth.net wrote: >>> Message: 15 >>> Date: Sat, 5 Feb 2022 14:53:59 -0600 >>> From: Ronnie Hull >>> To: Dick Dievendorff >>> Cc:Elecraft@mailman.qth.net <mailto:cc%3aelecr...@mailman.qth.net> >>> Subject: Re: [Elecraft] KPA1500 wattmeter adjustment >>> Message-ID: >>> Content-Type: text/plain; charset=utf-8 >>> >>> Lucky your that close! My K3, P:, Lp100 and kpa1500 are all >>wa different. I accept the LPA100 as being correct! >>> >>> Ron W5SUM >> >>__ >>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 marklgoldb...@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 w5...@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] KPA1500 wattmeter adjustment
Power measurements can be accomplished in other ways. One is to use an
RF Amp meter and a known value load. Broadcast stations have done it
this way for years. Hence, 4.4 amps into 50 ohms is 1000 watts.
Another way is to use the voltage across a value of R and calculate
power. Thus 223.6 volts across 50 ohms is 1000 watts. And finally if
the voltage and current is known, then E x I = P. The LP-100 series,
as I understand, uses two methods, one measuring current and one
measuring voltage and calculates power. The instrument also costs in the
neighborhood of $500+.
Most ham meters, including the Bird series are voltage sensing devices
and presume the load to be some value which was used for calibration.
Thus if the meter is in a true 50 ohm circuit, it will most likely be
correct within the percentage of full scale accuracy. However, if the
meter was originally calibrated for 50 ohms and it is in a 20 ohm
circuit the error will be significant. Thus most ham type power meters
are "relative reading" instruments, and not absolute measuring instruments.
RF Amp meters are relatively easy to verify accuracy. Being
thermocouple devices, one can apply 60 Hz of some value of voltage and a
known load and then determine the accuracy. Again, I = E/R.
Did we forget about how to use Ohms Law? Seems so. Or perhaps we
never knew to start with.
73
Bob, K4TAX
On 2/6/2022 12:47 PM, Mark Goldberg wrote:
The only way to really know for sure is to have a NIST traceable
calibrated wattmeter and have it calibrated on a regular basis. Hams
are generally too cheap to do that. The LP100 does come calibrated, so
that would be my go to reference, but I'll bet Hams will hardly ever
get the calibration checked after purchase. I could not find how much
they charge for that service. Even that is only calibrated to 5% with
3% typical. So, if you off 5W while measuring 100W, who knows, it
might be just the calibration error.
73,
Mark
W7MLG
On Sun, Feb 6, 2022 at 10:11 AM Bob McGraw wrote:
'Twas said "a man with one watch always knows the time. A man
with 3 or
4 watches is never quite sure of the time.".
I just recently went through power calibrations on my K3S and my
KPA500. All now agree with the power meter reference I used.
Also, this
was done using a known 50.5 ohm dummy load. On the antennas, even
though SWR is indicated 1.1:1, there will be differences due to
difference line complex impedance's.
73
Bob, K4TAX
On 2/6/2022 9:51 AM, elecraft-requ...@mailman.qth.net wrote:
> Message: 15
> Date: Sat, 5 Feb 2022 14:53:59 -0600
> From: Ronnie Hull
> To: Dick Dievendorff
> Cc:Elecraft@mailman.qth.net <mailto:cc%3aelecr...@mailman.qth.net>
> Subject: Re: [Elecraft] KPA1500 wattmeter adjustment
> Message-ID:
> Content-Type: text/plain; charset=utf-8
>
> Lucky your that close! My K3, P:, Lp100 and kpa1500 are all
wa different. I accept the LPA100 as being correct!
>
> Ron W5SUM
__
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Re: [Elecraft] KPA1500 wattmeter adjustment
On 2/6/2022 10:59 AM, N2TK via Elecraft wrote: 3-5% is fine in my book. As an engineer who has worked in manufacturing, I consider that a fine performance spec. Note that it is 3% typical, 5% worst case, of the READING, whereas for Bird, it's 5% of full scale, and the LP100A probes are calibrated over a wider frequency range. My probes are factory calibrated. 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] KPA1500 wattmeter adjustment
Hi Mark,N8LP sent me a note concerning the calibration of the LP100 at high frequencies. I use the LP-100 as a reference. I just packed up the LP100, cables and head to ship to Larry tomorrow. I have had it for a long time. Who knows? I may have done something dumb with it. 3-5% is fine in my book. 73,N2TK, Tony -Original Message- From: Mark Goldberg To: Bob McGraw Cc: Elecraft Mailing List Sent: Sun, Feb 6, 2022 1:47 pm Subject: Re: [Elecraft] KPA1500 wattmeter adjustment The only way to really know for sure is to have a NIST traceable calibrated wattmeter and have it calibrated on a regular basis. Hams are generally too cheap to do that. The LP100 does come calibrated, so that would be my go to reference, but I'll bet Hams will hardly ever get the calibration checked after purchase. I could not find how much they charge for that service. Even that is only calibrated to 5% with 3% typical. So, if you off 5W while measuring 100W, who knows, it might be just the calibration error. 73, Mark W7MLG On Sun, Feb 6, 2022 at 10:11 AM Bob McGraw wrote: > 'Twas said "a man with one watch always knows the time. A man with 3 or > 4 watches is never quite sure of the time.". > > I just recently went through power calibrations on my K3S and my > KPA500. All now agree with the power meter reference I used. Also, this > was done using a known 50.5 ohm dummy load. On the antennas, even > though SWR is indicated 1.1:1, there will be differences due to > difference line complex impedance's. > > 73 > > Bob, K4TAX > > > On 2/6/2022 9:51 AM, elecraft-requ...@mailman.qth.net wrote: > > Message: 15 > > Date: Sat, 5 Feb 2022 14:53:59 -0600 > > From: Ronnie Hull > > To: Dick Dievendorff > > Cc:Elecraft@mailman.qth.net > > Subject: Re: [Elecraft] KPA1500 wattmeter adjustment > > Message-ID: > > Content-Type: text/plain; charset=utf-8 > > > > Lucky your that close! My K3, P:, Lp100 and kpa1500 are all wa > different. I accept the LPA100 as being correct! > > > > Ron W5SUM > > __ > 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 marklgoldb...@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 tony@verizon.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] KPA1500 wattmeter adjustment
The only way to really know for sure is to have a NIST traceable calibrated wattmeter and have it calibrated on a regular basis. Hams are generally too cheap to do that. The LP100 does come calibrated, so that would be my go to reference, but I'll bet Hams will hardly ever get the calibration checked after purchase. I could not find how much they charge for that service. Even that is only calibrated to 5% with 3% typical. So, if you off 5W while measuring 100W, who knows, it might be just the calibration error. 73, Mark W7MLG On Sun, Feb 6, 2022 at 10:11 AM Bob McGraw wrote: > 'Twas said "a man with one watch always knows the time. A man with 3 or > 4 watches is never quite sure of the time.". > > I just recently went through power calibrations on my K3S and my > KPA500. All now agree with the power meter reference I used. Also, this > was done using a known 50.5 ohm dummy load. On the antennas, even > though SWR is indicated 1.1:1, there will be differences due to > difference line complex impedance's. > > 73 > > Bob, K4TAX > > > On 2/6/2022 9:51 AM, elecraft-requ...@mailman.qth.net wrote: > > Message: 15 > > Date: Sat, 5 Feb 2022 14:53:59 -0600 > > From: Ronnie Hull > > To: Dick Dievendorff > > Cc:Elecraft@mailman.qth.net > > Subject: Re: [Elecraft] KPA1500 wattmeter adjustment > > Message-ID: > > Content-Type: text/plain; charset=utf-8 > > > > Lucky your that close! My K3, P:, Lp100 and kpa1500 are all wa > different. I accept the LPA100 as being correct! > > > > Ron W5SUM > > __ > 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 marklgoldb...@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
[Elecraft] KPA1500 wattmeter adjustment
'Twas said "a man with one watch always knows the time. A man with 3 or 4 watches is never quite sure of the time.". I just recently went through power calibrations on my K3S and my KPA500. All now agree with the power meter reference I used. Also, this was done using a known 50.5 ohm dummy load. On the antennas, even though SWR is indicated 1.1:1, there will be differences due to difference line complex impedance's. 73 Bob, K4TAX On 2/6/2022 9:51 AM, elecraft-requ...@mailman.qth.net wrote: Message: 15 Date: Sat, 5 Feb 2022 14:53:59 -0600 From: Ronnie Hull To: Dick Dievendorff Cc:Elecraft@mailman.qth.net Subject: Re: [Elecraft] KPA1500 wattmeter adjustment Message-ID: Content-Type: text/plain; charset=utf-8 Lucky your that close! My K3, P:, Lp100 and kpa1500 are all wa different. I accept the LPA100 as being correct! Ron W5SUM __ 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] KPA1500 wattmeter adjustment
Dick,Thanks for the tip. My KPA1500 is in the basement on a shelf right under my feet in the shack. I use Remote By Elecraft in the shack to monitor the amp.Took your tip and used the KPA1500 Utility > Operate to get to WMTR Adjust. This made it very easy to make changes and see the results right away.I used the LP-100 as the standard. But the readout does seem to drop off some (15% lower on 6M compared to 160M) as I go higher in frequency compared to the K3 showing 100W. Is it the LP-100 or the K3? Not sure at this stage if I should bother with anything else On the P3 I set the SensorScale to 474.On the KPA1500 The WMTR depended on the band. The range was from 92-99%. The largest readout spread comparing the LP-100, P3 and KPA1500 is now <6% with most bands <3%.This is as accurate as I need to be. I am now a happy camper.I assume I can't attach a spreadsheet. So if anyone wants a copy of my results let me know.73N2TK, Tony -Original Message- From: Dick Dievendorff To: tony@verizon.net Cc: elecraft@mailman.qth.net Sent: Sat, Feb 5, 2022 3:11 pm Subject: Re: [Elecraft] KPA1500 wattmeter adjustment If you turn in the Tech Mode menu item, there is a WMTR ADJUST menu item that might be easier to use than the command tester commands. 73 de Dick, K6KR > On Feb 5, 2022, at 10:33, N2TK via Elecraft wrote: > > If I measure the power out on my K3 (set to 100W), P3, LP-100 and KPA1500 > (power on but in standby), they all read quite close on 10-160M into a dummy > load. On 6M the P3 reads 16% higher than the other three. If I use 20W drive > from the K3 and put the KPA1500 in operate mode, the P3 and LP-100 read quite > close into a dummy load. But the KPA1500 reads about 6-11% higher on > 6-160M.The readings are close enough not to be concerned. Looking at the > KPA1500 manual there are commands to adjust the wattmeter readouts by band. > I tried commands in the KPA1500 utility Command Tester (^RV;) as an example, > but nothing happened. Checked the Port tab to make sure the utility is > connected to the amp.What am I doing wrong? Can you do what I am trying tp do > from the Command Tester.TnxN2TK, Tony > __ > 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 d...@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] KPA1500 wattmeter adjustment
Lucky your that close! My K3, P:, Lp100 and kpa1500 are all wa different. I accept the LPA100 as being correct! Ron W5SUM Sent from my iPhone > On Feb 5, 2022, at 2:11 PM, Dick Dievendorff wrote: > > If you turn in the Tech Mode menu item, there is a WMTR ADJUST menu item > that might be easier to use than the command tester commands. > > 73 de Dick, K6KR > >> On Feb 5, 2022, at 10:33, N2TK via Elecraft wrote: >> >> If I measure the power out on my K3 (set to 100W), P3, LP-100 and KPA1500 >> (power on but in standby), they all read quite close on 10-160M into a dummy >> load. On 6M the P3 reads 16% higher than the other three. If I use 20W drive >> from the K3 and put the KPA1500 in operate mode, the P3 and LP-100 read >> quite close into a dummy load. But the KPA1500 reads about 6-11% higher on >> 6-160M.The readings are close enough not to be concerned. Looking at the >> KPA1500 manual there are commands to adjust the wattmeter readouts by band. >> I tried commands in the KPA1500 utility Command Tester (^RV;) as an example, >> but nothing happened. Checked the Port tab to make sure the utility is >> connected to the amp.What am I doing wrong? Can you do what I am trying tp >> do from the Command Tester.TnxN2TK, Tony >> __ >> 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 d...@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 w5...@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] KPA1500 wattmeter adjustment
If you turn in the Tech Mode menu item, there is a WMTR ADJUST menu item that might be easier to use than the command tester commands. 73 de Dick, K6KR > On Feb 5, 2022, at 10:33, N2TK via Elecraft wrote: > > If I measure the power out on my K3 (set to 100W), P3, LP-100 and KPA1500 > (power on but in standby), they all read quite close on 10-160M into a dummy > load. On 6M the P3 reads 16% higher than the other three. If I use 20W drive > from the K3 and put the KPA1500 in operate mode, the P3 and LP-100 read quite > close into a dummy load. But the KPA1500 reads about 6-11% higher on > 6-160M.The readings are close enough not to be concerned. Looking at the > KPA1500 manual there are commands to adjust the wattmeter readouts by band. > I tried commands in the KPA1500 utility Command Tester (^RV;) as an example, > but nothing happened. Checked the Port tab to make sure the utility is > connected to the amp.What am I doing wrong? Can you do what I am trying tp do > from the Command Tester.TnxN2TK, Tony > __ > 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 d...@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
[Elecraft] KPA1500 wattmeter adjustment
If I measure the power out on my K3 (set to 100W), P3, LP-100 and KPA1500 (power on but in standby), they all read quite close on 10-160M into a dummy load. On 6M the P3 reads 16% higher than the other three. If I use 20W drive from the K3 and put the KPA1500 in operate mode, the P3 and LP-100 read quite close into a dummy load. But the KPA1500 reads about 6-11% higher on 6-160M.The readings are close enough not to be concerned. Looking at the KPA1500 manual there are commands to adjust the wattmeter readouts by band. I tried commands in the KPA1500 utility Command Tester (^RV;) as an example, but nothing happened. Checked the Port tab to make sure the utility is connected to the amp.What am I doing wrong? Can you do what I am trying tp do from the Command Tester.TnxN2TK, Tony __ 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
