KPA500 power output starts out low, then goes up
Locked
KPA500 power output starts out low, then goes up
 
|
Hi All,
Maybe you can help with something that is baffling me. My KPA500 doesn't go to full output until I have spoken my callsign (when trying to get through a pileup) a few times. It starts off with 100 or so watts, and after a few iterations rises to the full 500W output. I see this both on the KPA500 LED bar, as well as on the P3 PEP output monitored by P3TXMON. My full setup is K3S+KPA500+KAT500+P3+P3TXMON. All devices run the latest released firmware. Any thoughts much appreciated! Barthold AD0RM ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: KPA500 power output starts out low, then goes up
|
|
Hi Barthold,
Maybe the K3S output is ramping up slowly. Do you notice this with the KPA500 off? Running the TX Gain Calibration in the K3 Utility might help in that case. 73, Vic, 4X6GP Rehovot, Israel Formerly K2VCO http://www.qsl.net/k2vco/ On 14 Nov 2016 00:51, Barthold Lichtenbelt via Elecraft wrote: > Hi All, > > > > Maybe you can help with something that is baffling me. My KPA500 doesn't go > to full output until I have spoken my callsign (when trying to get through a > pileup) a few times. It starts off with 100 or so watts, and after a few > iterations rises to the full 500W output. I see this both on the KPA500 LED > bar, as well as on the P3 PEP output monitored by P3TXMON. My full setup is > K3S+KPA500+KAT500+P3+P3TXMON. All devices run the latest released firmware. > > > > Any thoughts much appreciated! > > > > Barthold > > AD0RM Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
|
|
That hasn’t helped my KPA500. I notice it particularly after a band change.
…bill nr4c > On Nov 13, 2016, at 10:58 PM, Vic Rosenthal 4X6GP <[hidden email]> wrote: > > Hi Barthold, > > Maybe the K3S output is ramping up slowly. Do you notice this with the KPA500 off? Running the TX Gain Calibration in the K3 Utility might help in that case. > > 73, > Vic, 4X6GP > Rehovot, Israel > Formerly K2VCO > http://www.qsl.net/k2vco/ > > On 14 Nov 2016 00:51, Barthold Lichtenbelt via Elecraft wrote: >> Hi All, >> >> >> >> Maybe you can help with something that is baffling me. My KPA500 doesn't go >> to full output until I have spoken my callsign (when trying to get through a >> pileup) a few times. It starts off with 100 or so watts, and after a few >> iterations rises to the full 500W output. I see this both on the KPA500 LED >> bar, as well as on the P3 PEP output monitored by P3TXMON. My full setup is >> K3S+KPA500+KAT500+P3+P3TXMON. All devices run the latest released firmware. >> >> >> >> Any thoughts much appreciated! >> >> >> >> Barthold >> >> AD0RM > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
|
|
Hi,
How about following Vic, 4X6GP's advice and test the K3 without the KPA500 in circuit? Your symptoms are exactly as if the K3 TX calibration is badly out of wack as he suggests. The fact that a band change makes it worse is a dead give-away. A band change makes the K3's ALC algorithm reset itself to defaults and these defaults are set by the TX gain calibration. Your situation seems a bit extreme, though, with only 20% initial power so there may be other problems. But please test this out without the KPA500 in circuit. And surely eliminate antenna problems by testing into a dummy load. AB2TC - Knut
|
|
|
just did that. no help.
…bill > On Nov 14, 2016, at 8:22 PM, ab2tc <[hidden email]> wrote: > > Hi, > > How about following Vic, 4X6GP's advice and test the K3 without the KPA500 > in circuit? Your symptoms are exactly as if the K3 TX calibration is badly > out of wack as he suggests. The fact that a band change makes it worse is a > dead give-away. A band change makes the K3's ALC algorithm reset itself to > defaults and these defaults are set by the TX gain calibration. Your > situation seems a bit extreme, though, with only 20% initial power so there > may be other problems. But please test this out without the KPA500 in > circuit. And surely eliminate antenna problems by testing into a dummy load. > > AB2TC - Knut > > > > > Bill Conkling wrote >> That hasn’t helped my KPA500. I notice it particularly after a band >> change. >> >> …bill nr4c >> >> >>> On Nov 13, 2016, at 10:58 PM, Vic Rosenthal 4X6GP < > >> k2vco.vic@ > >> > wrote: >>> >>> Hi Barthold, >>> >>> Maybe the K3S output is ramping up slowly. Do you notice this with the >>> KPA500 off? Running the TX Gain Calibration in the K3 Utility might help >>> in that case. >>> >>> 73, >>> Vic, 4X6GP >>> Rehovot, Israel >>> Formerly K2VCO >>> http://www.qsl.net/k2vco/ >>> >>> On 14 Nov 2016 00:51, Barthold Lichtenbelt via Elecraft wrote: >>>> Hi All, >>>> >>>> >>>> >>>> Maybe you can help with something that is baffling me. My KPA500 doesn't >>>> go >>>> to full output until I have spoken my callsign (when trying to get >>>> through a >>>> pileup) a few times. It starts off with 100 or so watts, and after a few >>>> iterations rises to the full 500W output. I see this both on the KPA500 >>>> LED >>>> bar, as well as on the P3 PEP output monitored by P3TXMON. My full >>>> setup is >>>> K3S+KPA500+KAT500+P3+P3TXMON. All devices run the latest released >>>> firmware. >>>> >>>> >>>> >>>> Any thoughts much appreciated! >>>> >>>> >>>> >>>> Barthold >>>> >>>> AD0RM >>> ______________________________________________________________ >>> Elecraft mailing list >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft <http://mailman.qth.net/mailman/listinfo/elecraft> >>> Help: http://mailman.qth.net/mmfaq.htm <http://mailman.qth.net/mmfaq.htm> >>> Post: mailto: > >> Elecraft@.qth > >>> >>> This list hosted by: http://www.qsl.net <http://www.qsl.net/> >>> Please help support this email list: http://www.qsl.net/donate.html <http://www.qsl.net/donate.html> >>> Message delivered to > >> nr4c@ > >> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft <http://mailman.qth.net/mailman/listinfo/elecraft> >> Help: http://mailman.qth.net/mmfaq.htm <http://mailman.qth.net/mmfaq.htm> >> Post: mailto: > >> Elecraft@.qth > >> >> This list hosted by: http://www.qsl.net <http://www.qsl.net/> >> Please help support this email list: http://www.qsl.net/donate.html <http://www.qsl.net/donate.html> >> Message delivered to > >> lists+1215531472858-365791@.nabble > > > > > > -- > View this message in context: http://elecraft.365791.n2.nabble.com/KPA500-power-output-starts-out-low-then-goes-up-tp7623993p7624027.html <http://elecraft.365791.n2.nabble.com/KPA500-power-output-starts-out-low-then-goes-up-tp7623993p7624027.html> > Sent from the Elecraft mailing list archive at Nabble.com <http://nabble.com/>. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: KPA500 power output starts out low, then goes up
|
|
In reply to this post by ab2tc
Thanks all for all the suggestions!
Fred Cady privately suggested making sure my ALC and Mic gain are set correctly. I tuned that some more, and it is a lot better, but still doesn't immediately go to full power output. I will test without KPA500 next. I have two antennas, so I can test with that too, to rule out antenna problems. As to answer your questions: > Does the SWR also change? Nope. Just power output. SWR graphs of my antenna are just fine (using a Rigexpert AA-600 antenna analyzer). > Have you measured the output of the K3 with a separate watt meter? I don't have one, but both the P3TXMON and the KPA power Leds show the effect. > How are the three boxes connected? Are you using the AuxIO cable that comes with the KPA and KAT? Yes, using the 15pin cables from K3S to KPA500 and KAT500. No separate key line. The P3 is connected with the RJ45 to dual serial connector cable. > And lastly, might you have ALC enabled in the K3 menu? Anything you can tell me about the setup will be helpful. Yes, TX ALC is ON (I never messed with that, had to look it up in the manual how to get it to show up even in the config). ALC Threshold for the KPA500 is set to 210. The K3S has these options: Second receiver, internal tuner (Set to bypass), frequency lock option, 4x 8 pole filters, DVR. Again, thanks for the help and suggestions. Quite a friendly bunch of people here! Barthold AD0RM -----Original Message----- From: Elecraft [mailto:[hidden email]] On Behalf Of ab2tc Sent: Monday, November 14, 2016 6:22 PM To: [hidden email] Subject: Re: [Elecraft] KPA500 power output starts out low, then goes up Hi, How about following Vic, 4X6GP's advice and test the K3 without the KPA500 in circuit? Your symptoms are exactly as if the K3 TX calibration is badly out of wack as he suggests. The fact that a band change makes it worse is a dead give-away. A band change makes the K3's ALC algorithm reset itself to defaults and these defaults are set by the TX gain calibration. Your situation seems a bit extreme, though, with only 20% initial power so there may be other problems. But please test this out without the KPA500 in circuit. And surely eliminate antenna problems by testing into a dummy load. AB2TC - Knut Bill Conkling wrote > That hasn’t helped my KPA500. I notice it particularly after a band > change. > > …bill nr4c > > >> On Nov 13, 2016, at 10:58 PM, Vic Rosenthal 4X6GP < > k2vco.vic@ > > wrote: >> >> Hi Barthold, >> >> Maybe the K3S output is ramping up slowly. Do you notice this with >> the >> KPA500 off? Running the TX Gain Calibration in the K3 Utility might >> help in that case. >> >> 73, >> Vic, 4X6GP >> Rehovot, Israel >> Formerly K2VCO >> http://www.qsl.net/k2vco/ >> >> On 14 Nov 2016 00:51, Barthold Lichtenbelt via Elecraft wrote: >>> Hi All, >>> >>> >>> >>> Maybe you can help with something that is baffling me. My KPA500 >>> doesn't go to full output until I have spoken my callsign (when >>> trying to get through a >>> pileup) a few times. It starts off with 100 or so watts, and after a >>> few iterations rises to the full 500W output. I see this both on the >>> KPA500 LED bar, as well as on the P3 PEP output monitored by >>> P3TXMON. My full setup is >>> K3S+KPA500+KAT500+P3+P3TXMON. All devices run the latest released >>> firmware. >>> >>> >>> >>> Any thoughts much appreciated! >>> >>> >>> >>> Barthold >>> >>> AD0RM >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto: > Elecraft@.qth >> >> This list hosted by: http://www.qsl.net Please help support this >> email list: http://www.qsl.net/donate.html Message delivered to > nr4c@ > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto: > Elecraft@.qth > > This list hosted by: http://www.qsl.net Please help support this email > list: http://www.qsl.net/donate.html Message delivered to > lists+1215531472858-365791@.nabble -- View this message in context: http://elecraft.365791.n2.nabble.com/KPA500-power-output-starts-out-low-then-goes-up-tp7623993p7624027.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: KPA500 power output starts out low, then goes up
|
|
Several things I would suggest:
1) Turn off external ALC in the K3. We recommend NOT using it with the KPA500 (or any other amp for that matter). 2) Run the test with the K3 connected to a power meter then a dummy load to see if the problem persists. If so, you probably need to recalibrate the K3. If it does not, then we need to look further at the K3-KPA connection. 3) Connect the output of the KPA500 to a high-power dummy load and test. Even though the RigExpert may indicate a good match, that is at very low power. At high power things can change, arcs may occur and other bad things may happen. Make sure the setup works just fine into a dummy load, THEN connect to the antenna. 4) The KPA500 can show you voltage and current for the PA transistors. Make note of each as you key up the K3 to see what is happening. They should go to fairly stable conditions fairly rapidly if the transmitter does the same. If it is taking its time, then look to the transmitter for the cause. Note that the KPA is either full on or off. It does not (nor can it) vary its output power in any other way. If there were a problem in the 15m LPF you could see a problem, but it would be persistent, not recovering as you indicate. So far I am not seeing anything that indicates the problem is in the KPA. Please run the above suggestions. I am very interested in the results. 73, Jack Brindle, W6FB Elecraft Engineering (sent a second time trying to get the email list to accept the email...) > On Nov 14, 2016, at 11:01 PM, Barthold Lichtenbelt via Elecraft <[hidden email]> wrote: > > Thanks all for all the suggestions! > > Fred Cady privately suggested making sure my ALC and Mic gain are set correctly. I tuned that some more, and it is a lot better, but still doesn't immediately go to full power output. > > I will test without KPA500 next. > > I have two antennas, so I can test with that too, to rule out antenna problems. > > As to answer your questions: > >> Does the SWR also change? > > Nope. Just power output. SWR graphs of my antenna are just fine (using a Rigexpert AA-600 antenna analyzer). > >> Have you measured the output of the K3 with a separate watt meter? > > I don't have one, but both the P3TXMON and the KPA power Leds show the effect. > >> How are the three boxes connected? Are you using the AuxIO cable that comes with the KPA and KAT? > > Yes, using the 15pin cables from K3S to KPA500 and KAT500. No separate key line. The P3 is connected with the RJ45 to dual serial connector cable. > >> And lastly, might you have ALC enabled in the K3 menu? Anything you can tell me about the setup will be helpful. > > Yes, TX ALC is ON (I never messed with that, had to look it up in the manual how to get it to show up even in the config). > > ALC Threshold for the KPA500 is set to 210. > > The K3S has these options: Second receiver, internal tuner (Set to bypass), frequency lock option, 4x 8 pole filters, DVR. > > Again, thanks for the help and suggestions. Quite a friendly bunch of people here! > > Barthold > AD0RM ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: KPA500 power output starts out low, then goes up
|
|
This might be a problem with the pin diode T/R switching in the KPA500.
73, Arie ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: KPA500 power output starts out low, then goes up
|
|
A TR switch failure would affect all bands. This one is a bit different. It will be interesting to see the cause when we finish troubleshooting.
Jack Brindle, W6FB Elecraft Engineering Sent from my iPhone > On Nov 16, 2016, at 12:04 PM, Arie Kleingeld PA3A <[hidden email]> wrote: > > This might be a problem with the pin diode T/R switching in the KPA500. > > > 73, > > Arie > > > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: KPA500 power output starts out low, then goes up
|
|
I didn't see anything in this thread that suggested that the problem
wasn't observed on all bands. Maybe I missed it? Also haven't noticed anyone suggest using the K3's "TUNE" function, instead of SSB modulation, as a test. If the output ramps up with the TUNE function, it's an output problem. If it doesn't, it might be an issue of insufficient audio input for SSB modulation. (AFAIK) the K3 will automatically boost the audio input if it detects that there's not enough (a feature that I'm not particularly fond of). 73, ~iain / N6ML On Wed, Nov 16, 2016 at 9:56 AM, Jack Brindle <[hidden email]> wrote: > A TR switch failure would affect all bands. This one is a bit different. It will be interesting to see the cause when we finish troubleshooting. > > Jack Brindle, W6FB > Elecraft Engineering > > Sent from my iPhone > >> On Nov 16, 2016, at 12:04 PM, Arie Kleingeld PA3A <[hidden email]> wrote: >> >> This might be a problem with the pin diode T/R switching in the KPA500. >> >> >> 73, >> >> Arie >> >> >> >> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[hidden email] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to [hidden email] > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: KPA500 power output starts out low, then goes up
|
|
> I didn't see anything in this thread that suggested that the problem
wasn't observed on all bands. Maybe I missed it? I see it on 20m, 40m, 80m, on two different antennas. Haven't tried any other bands. > Also haven't noticed anyone suggest using the K3's "TUNE" function, instead of SSB modulation, as a test. Excellent idea! It does NOT happen when I use the TUNE function. Not with the KPA500 in standby nor in operation. Tried 20m and 40m. > If it doesn't, it might be an issue of insufficient audio input for SSB modulation. (AFAIK) the K3 will automatically boost the audio input if it detects that there's not enough (a feature that I'm not particularly fond of). I carefully tuned the Mic gain and Compression as per the manual. ALC goes up to 5 or 6 bars, compression below 10 dB when I speak in my normal voice. So that suggests input side is OK? Barthold AD0RM -----Original Message----- From: Elecraft [mailto:[hidden email]] On Behalf Of iain macdonnell - N6ML Sent: Wednesday, November 16, 2016 11:12 AM To: Jack Brindle Cc: Elecraft Reflector Subject: Re: [Elecraft] KPA500 power output starts out low, then goes up I didn't see anything in this thread that suggested that the problem wasn't observed on all bands. Maybe I missed it? Also haven't noticed anyone suggest using the K3's "TUNE" function, instead of SSB modulation, as a test. If the output ramps up with the TUNE function, it's an output problem. If it doesn't, it might be an issue of insufficient audio input for SSB modulation. (AFAIK) the K3 will automatically boost the audio input if it detects that there's not enough (a feature that I'm not particularly fond of). 73, ~iain / N6ML On Wed, Nov 16, 2016 at 9:56 AM, Jack Brindle <[hidden email]> wrote: > A TR switch failure would affect all bands. This one is a bit different. It will be interesting to see the cause when we finish troubleshooting. > > Jack Brindle, W6FB > Elecraft Engineering > > Sent from my iPhone > >> On Nov 16, 2016, at 12:04 PM, Arie Kleingeld PA3A <[hidden email]> wrote: >> >> This might be a problem with the pin diode T/R switching in the KPA500. >> >> >> 73, >> >> Arie >> >> >> >> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[hidden email] >> >> This list hosted by: http://www.qsl.net Please help support this >> email list: http://www.qsl.net/donate.html Message delivered to >> [hidden email] > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net Please help support this email > list: http://www.qsl.net/donate.html Message delivered to > [hidden email] Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: KPA500 power output starts out low, then goes up
|
|
In reply to this post by Iain MacDonnell - N6ML-2
I had the KPA500 PIN diode problem in 2015, and it started on one band
only. And it did not happen all the time. After a while it became worse and more bands were affected. So based on my experience with my KPA500 #1497, I suggested the PIN diode problem as a possiblity. I wonder what the serial number is of the KPA500 we are talking about, and whether it is produced before or after a change in the design(?). Anyway, when I presented this problem (how it presented itself on my KPA500) in the group and to elecraft support, I never got the right answer. After basic faultfinding I found that the PIN diode circuit was causing the strange behaviour of the linear and then... presto... there was a elecraft-mod that I never heard of before. It contained a few new switching components and some capactiors for one of the LP-filters. After putting those in, problem was solved. My K3 line and me lived happy ever after :-). 73 Arie PA3A ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: KPA500 power output starts out low, then goes up
|
|
In reply to this post by Elecraft mailing list
Hi All,
Problem solved! The problem was in my K3S. A simple Transmitter Gain calibration procedure fixed it. (This calibration you start in the K3 PC utility). Now I am very curious to better understand why this calibration fixed it. Also curious to know why a 6 week old K3S, built by the factory, needed a calibration. Bad luck? Any config settings I could have done that affect this behavior? Many thanks to both Jack Brindle and Craig Smith from Elecraft who both jumped on this to help me troubleshoot. Jack contacted me while he was on vacation (!). Craig called me (!) to help me troubleshoot, just from reading this discussion thread. The reason it took a while to fix is because I first had to order a dummy load so I could perform the TX gain calibration procedure. Jack, Craig, you guys rock!! Barthold AD0RM -----Original Message----- From: Elecraft [mailto:[hidden email]] On Behalf Of Barthold Lichtenbelt via Elecraft Sent: Wednesday, November 16, 2016 1:25 PM To: 'iain macdonnell - N6ML'; 'Jack Brindle' Cc: 'Elecraft Reflector' Subject: Re: [Elecraft] KPA500 power output starts out low, then goes up > I didn't see anything in this thread that suggested that the problem wasn't observed on all bands. Maybe I missed it? I see it on 20m, 40m, 80m, on two different antennas. Haven't tried any other bands. > Also haven't noticed anyone suggest using the K3's "TUNE" function, instead of SSB modulation, as a test. Excellent idea! It does NOT happen when I use the TUNE function. Not with the KPA500 in standby nor in operation. Tried 20m and 40m. > If it doesn't, it might be an issue of insufficient audio input for > SSB modulation. (AFAIK) the K3 will automatically boost the audio input if it detects that there's not enough (a feature that I'm not particularly fond of). I carefully tuned the Mic gain and Compression as per the manual. ALC goes up to 5 or 6 bars, compression below 10 dB when I speak in my normal voice. So that suggests input side is OK? Barthold AD0RM -----Original Message----- From: Elecraft [mailto:[hidden email]] On Behalf Of iain macdonnell - N6ML Sent: Wednesday, November 16, 2016 11:12 AM To: Jack Brindle Cc: Elecraft Reflector Subject: Re: [Elecraft] KPA500 power output starts out low, then goes up I didn't see anything in this thread that suggested that the problem wasn't observed on all bands. Maybe I missed it? Also haven't noticed anyone suggest using the K3's "TUNE" function, instead of SSB modulation, as a test. If the output ramps up with the TUNE function, it's an output problem. If it doesn't, it might be an issue of insufficient audio input for SSB modulation. (AFAIK) the K3 will automatically boost the audio input if it detects that there's not enough (a feature that I'm not particularly fond of). 73, ~iain / N6ML On Wed, Nov 16, 2016 at 9:56 AM, Jack Brindle <[hidden email]> wrote: > A TR switch failure would affect all bands. This one is a bit different. It will be interesting to see the cause when we finish troubleshooting. > > Jack Brindle, W6FB > Elecraft Engineering > > Sent from my iPhone > >> On Nov 16, 2016, at 12:04 PM, Arie Kleingeld PA3A <[hidden email]> wrote: >> >> This might be a problem with the pin diode T/R switching in the KPA500. >> >> >> 73, >> >> Arie >> >> >> >> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[hidden email] >> >> This list hosted by: http://www.qsl.net Please help support this >> email list: http://www.qsl.net/donate.html Message delivered to >> [hidden email] > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net Please help support this email > list: http://www.qsl.net/donate.html Message delivered to > [hidden email] Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
«
Return to Elecraft
|
1 view|%1 views
| Free forum by Nabble | Edit this page |