Wow!! Bad news. Let's see if the amp can be made operational for the weekend.
First, what size fuses did you put in? There are two different ratings supplied: 6A for 240 volt mains and 12A for 120 volt mains. If you have 120 V mains and used the left-over fuses they were probably the 6A and would not survive the current demand. Be sure you get the right replacements. I noted that many hardware stores carry 12A fast blow (that's the right kind) labeled as "Microwave Oven Fuses". Before you turn on the unit with the new fuses, check the transformer tap setting as described in the Owner's manual under "Installation". They may have changed it at the factory and not put it back to what you had. You want to be sure you replicate the tap setting you used before. If you don't remember, put the yellow wire on the TAP lug and check the voltages produced as shown in your Owner's manual. Hope this gets you on the air for some fun this weekend! 73, Ron AC7AC -----Original Message----- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of ai6ii Sent: Friday, May 27, 2011 7:30 PM To: Elecraft@mailman.qth.net Subject: [Elecraft] KPA500 problems It is out of great frustration that I write this. What's up with Elecraft and the KPA500? I was so excited when KPA500 arrived May 11th. It was a culmination of six months of waiting and saving and finally it was here! Having previously built my K3, P3 and W2, this time I chose to get it factory built, mostly because I would be operational a month or two so sooner. BUT when I set it up everything worked great except for 20 meters. It failed to put out anything more than 270W on 14.MHz. I contacted Dale at Elecraft and we went through some 'over the phone' tests. He said he would need to talk with the engineers and called me back later in the day with more tests to run. Bottom line.it needed to be returned. He said it looked like a problem with the low pass filter. I boxed it up, paid USPS the $50 to send it back and waited. So far, okay, a little disappointing, but okay. I am not superstitions, but that was Friday 13th. So yesterday I received the KPA500 back with a letter explaining the low output on 14 MHz was due to three failed capacitors in the low pass filter. They were repaired and an upgrade/mod was also performed: "Front Panel VDD 5A Bypass Cap" (I haven't a clue what that means.) It had been bench tested for four hours and "KPA500 SN0026 meets or exceeds all factory specifications". Great. Good to go. And this is when it gets bad. I set all the cabling back up including the 1KW dummy load and turn the amp on..nothing. I check the rocker switch in back .nothing. Looking for troubleshooting info in the manual, I notice the instructions for setting up 115 vs. 220 voltage, and open the fuse box. Ah hah! No fuses .surprising because when I first got the amp it had fuses in place. There were a set of fuses included in the original packaging so I inserted them..turned it on.nothing.checked the fuses they were blown. And of course this is at 5:15 pm on the Friday before Memorial Day weekend. I though I would get a few hours of hamming in with the new amp. No such luck. I'll go get a couple more fuses tomorrow and try again, but I am not hopeful. I have to wait until Tuesday to call which means I have no one to talk to about this. That's why I am posting this hard luck story, out of frustration. This is one Elecraft enthusiast who is really bummed out. I hope you have better luck. I am surprised mine is so bad. ..mike AI6II ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
