Re: [Elecraft] KPA1500 RELIABILITY
I have a KPA1500 . One of the first ones built, ran perfectly until earlier this year, when without reason it went from 1400 watts to 700 watts while running CW, NO WARNING. The LDMOS DIED.. Returned to the factory for repair, cost me $718 plus my shipping costs. After about 12 weeks I received it back. . I have not yet put it back on the air because I have since gone back to my reliable Ameritron AL1500 . I can repair it without having to send it back for special repair because I do not have the tools to replace the LDMOS. Tubes are easy to change. Although it is nice to be able to change bands and be ready to transmit no tuning, 160-6 meters, I'm just not sure I trust it though, I need reliability. NOT SURPRISES. The question is, is there a common component failing? and it looks like that it is the LDMOS from the posts I am reading. Bruce WW8II On Sun, Oct 30, 2022 at 11:44 AM wrote: > Is there a common component failure with this KPA1500 amp or does something > different break every time? Is there a certain mode, power level or type > of > antenna/feedline that causes failures? I also monitor the SPE Expert list > and some people have multiple LDMOS failures while others have no issues > ever. N4ZR posted a similar question two months ago when someone else had > multiple LDMOS failures and I did not see any responses. > http://mailman.qth.net/pipermail/elecraft/2022-August/290628.html > > GL, > John KK9A > > > W3AB wrote: > > I don't have one but I do have access to one. It is making UPS rich > going back and forth. Is there a reliability issue with these amps? > > --- > 73 de W3AB/GEO > > > __ > 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 wa8...@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 RELIABILITY
Mine has worked flawlessly for the year or so that I've had it. I've pushed it pretty hard and for pretty long durations with some digital modes, as well. So far, so good. Tim On Mon, Oct 31, 2022 at 3:18 PM Frank Scolaro wrote: > Of the 5 people I know with the KPA1500, 3 of them have made a return trip > for LDMOS failure. Also had my RF-Kit blow up twice. Will have to fix my > old Henry 3k! > > Frank W2YK > > -Original Message- > From: Wes > Sent: Oct 31, 2022 6:02 PM > To: > Subject: Re: [Elecraft] KPA1500 RELIABILITY > > In my modest station (120V 20A) I run a KPA500, which has been fine, if > noisy. > > If I was to QRO I think I would opt for tubes. Less expensive, more > reliable, better linearity and quieter. > > Wes N7WS > > ps. Thanks for the J68HQ Qs > > > > On 10/31/2022 1:40 PM, Dr. William J. Schmidt wrote: > > --- Thinking of going back to tube amps because they are much more > > forgiving! > > > > > > Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ > PJ2/K9HZ > > VP2EHZ > > > > __ > 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 w...@arrl.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 ae...@worldwidedx.com > -- Owner, worldwidedx.com AE6LX, Amateur Radio __ 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 RELIABILITY
Of the 5 people I know with the KPA1500, 3 of them have made a return trip for LDMOS failure. Also had my RF-Kit blow up twice. Will have to fix my old Henry 3k! Frank W2YK -Original Message- From: Wes Sent: Oct 31, 2022 6:02 PM To: Subject: Re: [Elecraft] KPA1500 RELIABILITY In my modest station (120V 20A) I run a KPA500, which has been fine, if noisy. If I was to QRO I think I would opt for tubes. Less expensive, more reliable, better linearity and quieter. Wes N7WS ps. Thanks for the J68HQ Qs On 10/31/2022 1:40 PM, Dr. William J. Schmidt wrote: > --- Thinking of going back to tube amps because they are much more > forgiving! > > > Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ > VP2EHZ > __ 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 w...@arrl.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 RELIABILITY
In my modest station (120V 20A) I run a KPA500, which has been fine, if noisy. If I was to QRO I think I would opt for tubes. Less expensive, more reliable, better linearity and quieter. Wes N7WS ps. Thanks for the J68HQ Qs On 10/31/2022 1:40 PM, Dr. William J. Schmidt wrote: --- Thinking of going back to tube amps because they are much more forgiving! Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ __ 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 RELIABILITY
Hi William, Is the station using this amplifier operated in person, or remotely? If remotely, what operating conditions are being monitored by the remote operator? What "traps" are provided by the control circuitry to prevent an operator from doing something dumb? This is one of the things I learned from a very good A/V contractor (K9IKZ was the chief engineer) whose programming team designed a lot of automation systems. K5RC has reported reliability issues with power amps in the W7RN super-station, which is set up for remote operation. Don't recall which models, but I suspect Tom would be willing to share his experience. He did at the time on the NCCC reflector. 73, Jim K9YC On 10/31/2022 1:40 PM, Dr. William J. Schmidt wrote: My KPA1500 just blew up for the third time... gonna go back again. Forced us to run LP in CQWW this weekend as it exploded just two days ahead of the contest. No reason for the explosion that I can tell... radio worked fine on the antenna system without the amp after the explosion. Previously it went back for: 1. MeanWell Power Supply failure. (Hey, it happens). 2. Blew up the blocking capacitors in the final output circuit (teeny suckers, no reason for it). This time I got a hard failure/low gain so figure it's gonna be final transistors. Thinking of going back to tube amps because they are much more forgiving! __ 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 RELIABILITY
My KPA1500 just blew up for the third time... gonna go back again. Forced us to run LP in CQWW this weekend as it exploded just two days ahead of the contest. No reason for the explosion that I can tell... radio worked fine on the antenna system without the amp after the explosion. Previously it went back for: 1. MeanWell Power Supply failure. (Hey, it happens). 2. Blew up the blocking capacitors in the final output circuit (teeny suckers, no reason for it). This time I got a hard failure/low gain so figure it's gonna be final transistors. Thinking of going back to tube amps because they are much more forgiving! Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ email: b...@wjschmidt.com -Original Message- From: elecraft-boun...@mailman.qth.net On Behalf Of j...@kk9a.com Sent: Sunday, October 30, 2022 10:44 AM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] KPA1500 RELIABILITY Is there a common component failure with this KPA1500 amp or does something different break every time? Is there a certain mode, power level or type of antenna/feedline that causes failures? I also monitor the SPE Expert list and some people have multiple LDMOS failures while others have no issues ever. N4ZR posted a similar question two months ago when someone else had multiple LDMOS failures and I did not see any responses. http://mailman.qth.net/pipermail/elecraft/2022-August/290628.html GL, John KK9A W3AB wrote: I don't have one but I do have access to one. It is making UPS rich going back and forth. Is there a reliability issue with these amps? --- 73 de W3AB/GEO __ 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 b...@wjschmidt.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] For Sale: Elecraft K4D-F like new
I have a K4-D-F Serial #0492 For Sale with almost zero use. Still has plastic protection over the display!! It was ordered June 2021 and delivered January 2022. It stayed in it's sealed factory box for 8 months as I was up in New York.Only 3-4 QSO's made. Comes with the factory box and packing, All cables, factory manual as well as the ATU module and digital factory module installed and the hand microphone. Just too much radio for me.. Been licensed 56 years! Too much band noise here with my very modest antenna. Asking $5000 Local pick up ONLY No shipping.. I will be happy to provide digital photo's. Radio is in mint condition, fully operational.. Please text/call 941-302-6444 with any questions Thanks.. Steve/k2we ex:3W6WE Siesta Key/Sarasota, FL __ 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] 20M SSB Net Oct. 30th 2022
We carried on despite the CQWW contest. Thanks to those who took a break from the contest to join us on the net. Under the heavy QRM the relays, NS7P, N6JW, WM6P and N8SBE were a tremendous help. Please join us next Sunday at 1800Z on 14.3035. The following stations participated this week. Brian, K1NW Call Name State MANUF MODEL S/N K1NW Brian RI ELECRAFT K4D #863 (guest NC) K8NU Carl OHYAESU FTDX101D W4DML Doug TNELECRAFT K3 #6433 N8SBE Dave MI ELECRAFT K3S #11361 (relay) KK5LD Dan TX ELECRAFT K2 #223 W9EJB Ed IN ELECRAFT K4D #498 KG0KP Jim MOELECRAFT K3 #1442 K6FW Frank CA ELECRAFT K3S #11672 (relay) KO5V Jim NM ELECRAFT K2 #7225 NS7PPhil OR ELECRAFT K3 #1826 (relay) AE6JV BillNH ELECRAFT K3 #6299 N6JW John CA ELECRAFT K3 #936 W7OL Allen OR ELECRAFT K4D #656 WM6P SteveGA ELECRAFT K4D #436 (relay) WW4JF John TN ELECRAFT K3S #11177 W5COG Scott OK ELECRAFT K3 #4539 W7QHD Kurt AZ ELECRAFT KX3 #8697 VA6GWS Brian AB ELECRAFT K2 #156 KD0TOV MarkMN KENWOOD TS120S K5OSBRoy OK YAESUFT991A W1DFB Don AZ ELECRAFT K2 #2937 W9PDP Pat INICOM IC7300 __ 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] Elecraft CW Net Report
Good Evening, Conditions were better than last week. There was some rapid QSB on everyone. I scanned twenty meters before the first net. There was one DX pileup with a few casual contacts but not much more. It is rainy and cool along the coast. Fall colors are fading in the Midwest but the drought remains. Here it is wet enough to allow major burning but I have not seen any puddles. On 14050.5 kHz at 2200z: W0CZ - Ken - ND NO8V - John - MI K6XK - Roy - IA NS4V - David - NC K4JPN - Steve - GA On 7047.5 kHz at z: W0CZ - Ken - ND KG7V - Marv - WA K0DTJ - Brian - CA K6PJV - Dale - CA Until next week 73, Kevin. KD5ONS - 0 = I1 + I2 + ... + In __ 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
