Paula Keezer NX1P modified a KPA500 to allow it to be driven to about 500 watts by a KX3. She published it - but I can not find it on the web. The mod increased the gain by less than 3 db (seems I recall 2.something). You would need the 12 to 15 watts to drive it to about 500 watts.
The modification involved removing the input pad and modifying the feed back loop to the microprocessor. I thought about doing the mod to be able to run a net with my KX3 if my K3 quit. I have a KXPA and decided not to do the modification. I can just remove my KX3 & KXPA from my truck if I ever need a backup to drive the KPA500. Probably 10 minutes work and find the bag of portable cables. BTW - Ms. Keezer's modification was very detailed and she had many cautions regarding doing the modification. It defiantly was not a matter of "cutting a jumper" to remove the input pad. You need remove the pad parts and change the number of turns in a transformer. Defiantly would void the warranty and make factory repairs iffy depending on Elecraft's policies. Other manufacturers I have worked with would restore the amp to factory while repairing it. As a ham you are not limited to the 15 db gain restriction - the manufacturer is but not you. 73 George AI4VZ -----Original Message----- From: Charlie T Sent: Thursday, June 18, 2020 9:06 AM To: 'Nr4c' Cc: [email protected] Subject: Re: [Elecraft] Future of KPA500 & KAT500 Isn't there some sort of "jumper" or ???, that will increase the gain to something other than the ridiculous and prohibitive +13 dB figure, for "international" (wink-wink) sales, sorta like the "MARS" mod in almost all radios these days? 99.9% of the chicken band users today are happy with their 5 watt radios. However, that restrictive and useless +13 gain law does NOTHING to stop the REALLY big guns on 27.025 who typically run amps using tubes that have HANDLES on them! (I've personally seen channel 6 mobile set-ups running power in excess of 25 kilowatts.) 73, Charlie k3ICH -----Original Message----- From: [email protected] <[email protected]> On Behalf Of Nr4c Sent: Wednesday, June 17, 2020 3:14 PM To: Paul Gacek <[email protected]> Cc: Don Putnick <[email protected]>; Elecraft Reflector <[email protected]> Subject: Re: [Elecraft] Future of KPA500 & KAT500 The KAT500 has three antenna out ports. It only needs one In so the KPA500 needs only one out port. As for the 10 W in and 500 out idea. That is prohibited by law. They’re only allowed to sell an amp with max gain of 13dB. Sent from my iPhone ...nr4c. bill ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
