[KPA1500] Input Power
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Hello Elecrafter,
I have read the FAQ for the KPA1500. But there are no informations neither to the minimal or maximal input power nor to the gain. Or did I miss something? 73/72 de Ingo, DK3RED - Don't forget: the fun is the power! www.qrp4fun.de - [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] |
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The gain limit of 15 dB is set by the FCC. There is a move afoot to have
them drop that particular requirement but the FCC also moves a "glacial" pace. No telling when it might happen. On 5/10/2017 12:30 PM, Ingo Meyer, DK3RED wrote: > Hello Elecrafter, > > > I have read the FAQ for the KPA1500. But there are no informations > neither to the minimal or maximal input power nor to the gain. Or did I > miss something? > > > 73/72 de Ingo, DK3RED - Don't forget: the fun is the power! > www.qrp4fun.de - [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] > -- R. Kevin Stover AC0H FISTS #11993 SKCC #215 NAQCC #3441 ARRL ______________________________________________________________ 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: [KPA1500] Input Power
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Hello Kevin and all Elecrafter,
> The gain limit of 15 dB is set by the FCC. There is a move afoot to have them drop that > particular requirement but the FCC also moves a "glacial" pace. No telling when it might > happen. Thanks for the answers online an offline! 73/72 de Ingo, DK3RED - Don't forget: the fun is the power! www.qrp4fun.de - [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: [KPA1500] Input Power
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Hello Mike,
> Hi, Did you get answer for AC input power demand?   VA or power factor? No, only for the input power (see below), which I want to know. 1500 watts output = 61.8 dBm --> 15 dB gain --> 46.8 dBm = 47.5 ... 48 watts input >> The gain limit of 15 dB is set by the FCC. ... 73/72 de Ingo, DK3RED - Don't forget: the fun is the power! www.qrp4fun.de - [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: [KPA1500] Input Power
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All of those popular devices have gain more than 15 dB... so there is a pad in the amp to keep the gain at 15 dB. One would think that a "tweak" will evolve to modify the pad (and possibly the firmware) to eliminate this bothersome limit.
Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois Owner – Operator Villa Grand Piton - J68HZ Soufriere, St. Lucia W.I. Rent it: www.VillaGrandPiton.com email: [hidden email] > On May 11, 2017, at 4:49 PM, Ingo Meyer, DK3RED <[hidden email]> wrote: > > Hello Mike, > >> Hi, Did you get answer for AC input power demand?   VA or power factor? > > No, only for the input power (see below), which I want to know. > > 1500 watts output = 61.8 dBm --> 15 dB gain --> 46.8 dBm = 47.5 ... 48 watts input > >>> The gain limit of 15 dB is set by the FCC. ... > > 73/72 de Ingo, DK3RED - Don't forget: the fun is the power! > www.qrp4fun.de - [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] |
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Probably an unauthorized modification after the introduction of the KPA1500
will become available; similar to the one for the KPA500 by Paula Keezer NX1P. Haven't tried it but looks to be well thought out. 73 George AI4VZ -----Original Message----- From: Dr. William J. Schmidt Sent: Thursday, May 11, 2017 9:43 PM To: Ingo Meyer, DK3RED Cc: Elecraft Subject: Re: [Elecraft] [KPA1500] Input Power All of those popular devices have gain more than 15 dB... so there is a pad in the amp to keep the gain at 15 dB. One would think that a "tweak" will evolve to modify the pad (and possibly the firmware) to eliminate this bothersome limit. Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois Owner – Operator Villa Grand Piton - J68HZ Soufriere, St. Lucia W.I. Rent it: www.VillaGrandPiton.com email: [hidden email] > On May 11, 2017, at 4:49 PM, Ingo Meyer, DK3RED <[hidden email]> wrote: > > Hello Mike, > >> Hi, Did you get answer for AC input power demand?   VA or power >> factor? > > No, only for the input power (see below), which I want to know. > > 1500 watts output = 61.8 dBm --> 15 dB gain --> 46.8 dBm = 47.5 ... 48 > watts input > >>> The gain limit of 15 dB is set by the FCC. ... > > 73/72 de Ingo, DK3RED - Don't forget: the fun is the power! > www.qrp4fun.de - [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] --- This email has been checked for viruses by AVG. http://www.avg.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] |
Re: [KPA1500] Input Power
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In reply to this post by Dr. William J. Schmidt, II
Using a pad would be bad design, as simply increasing the level of
negative feedback would help reduce distortion. The only way one could achieve a repeatable gain close to 15dB would be with negative feedback. Moreover, I assume it is an FCC condition that modification by the end not be easy. You can assume that CB users wanting to use illegal powers have access to soldering irons. Also, I would assume that the design gain is actually less than 15dB, to allow for component tolerances. -- David Woolley K2 06123 On 12/05/17 02:43, Dr. William J. Schmidt wrote: > All of those popular devices have gain more than 15 dB... so there is a pad in the amp to keep the gain at 15 dB. One would think that a "tweak" will evolve to modify the pad (and possibly the firmware) to eliminate this bothersome limit. ______________________________________________________________ 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] |
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Hopefully your assumptions are off track-
Sure would be nice addition to the kx3 73 all Dean K2WW On May 12, 2017 9:17 AM, "David Woolley" <[hidden email]> wrote: > Using a pad would be bad design, as simply increasing the level of > negative feedback would help reduce distortion. The only way one could > achieve a repeatable gain close to 15dB would be with negative feedback. > > Moreover, I assume it is an FCC condition that modification by the end not > be easy. You can assume that CB users wanting to use illegal powers have > access to soldering irons. > > Also, I would assume that the design gain is actually less than 15dB, to > allow for component tolerances. > > -- > David Woolley K2 06123 > > On 12/05/17 02:43, Dr. William J. Schmidt wrote: > >> All of those popular devices have gain more than 15 dB... so there is a >> pad in the amp to keep the gain at 15 dB. One would think that a "tweak" >> will evolve to modify the pad (and possibly the firmware) to eliminate this >> bothersome limit. >> > > ______________________________________________________________ > 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: [KPA1500] Input Power
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In reply to this post by David Woolley (E.L)
So are you saying that the KPA500 is a bad design?
I'm not aware of a single non-CB amplifier that doesn't use an input pad... Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ Owner - Operator Big Signal Ranch - K9ZC Staunton, Illinois Owner - Operator Villa Grand Piton - J68HZ Soufriere, St. Lucia W.I. Rent it: www.VillaGrandPiton.com Like us on Facebook! email: [hidden email] -----Original Message----- From: Elecraft [mailto:[hidden email]] On Behalf Of David Woolley Sent: Friday, May 12, 2017 8:17 AM To: [hidden email] Subject: Re: [Elecraft] [KPA1500] Input Power Using a pad would be bad design, as simply increasing the level of negative feedback would help reduce distortion. The only way one could achieve a repeatable gain close to 15dB would be with negative feedback. Moreover, I assume it is an FCC condition that modification by the end not be easy. You can assume that CB users wanting to use illegal powers have access to soldering irons. Also, I would assume that the design gain is actually less than 15dB, to allow for component tolerances. -- David Woolley K2 06123 On 12/05/17 02:43, Dr. William J. Schmidt wrote: > All of those popular devices have gain more than 15 dB... so there is a pad in the amp to keep the gain at 15 dB. One would think that a "tweak" will evolve to modify the pad (and possibly the firmware) to eliminate this bothersome limit. ______________________________________________________________ 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: [KPA1500] Input Power
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I'm suggesting that using a pad to control gain is bad design. A pad is
going to necessary to provide the correct 50 ohm termination for the driver. I would suggest that the main gain control component on the KPA500 was T2, although a more detailed analysis may show that some or all of the passive components between its secondary and the FET gates are involved, as well. In any case, I don't think Elecraft are going to comment on how the achieve FCC compliance, on the 1500, in too much detail, in case it could be interpreted as instructions for subverting that mechanism. At least not until they have approval. I notice total silence from the insiders on this, and the previous similar thread. -- David Woolley K2 06123 On 13/05/17 15:59, Dr. William J. Schmidt, II wrote: > So are you saying that the KPA500 is a bad design? > > I'm not aware of a single non-CB amplifier that doesn't use an input pad... > ______________________________________________________________ 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] |
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