[KPA500] - 144MHz Version?
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I was recently studying the schematics of the KPA500 and looked at the
specification of the VRF2933 devices which are used in the RF deck of the amplifier. I noted that the devices are rated to 150MHz which made me think a 144Mhz version of the KPA500 would be a nice addition for a K3 equipped with a K144XV 2m option (or indeed any 144MHz transceiver). Nearly all the existing KPA500 metalwork, PSU and front panel PCB (with different firmware and no band buttons) could be carried over with a different RF deck (perhaps using the same VRF2933 devices and heatsink). A 2m version could potentially be lower cost as the switchable complex LPF arrangement of the HF/6M KPA500 would not be required. The RF deck aside, the R&D costs would be low, using much of the already proven KPA500 hardware. The 500W output is ideal for here in the UK where the power limit is 400W. Even a 432Mhz version could be created although the VRF2933 devices would have to be replaced with something else - I suspect the demand for this 70cm version would be far lower than that for 144MHz and would not be cost effective for Elecraft. I currently use a Henry Tempo 2002 using two Eimac 8874 on 144MHz. I think that a 144MHz KPA500 would be cheaper than obtaining two replacement tubes for my existing amp! I would certainly be very interested in the purchase of a 144MHz KPA500 (KPAV500 ?) - anyone else? On a slightly different matter, I note that the KPA500 front panel PCB schematic also has an unused "2nd RF deck" connection - perhaps for a future KPA1000 utilising two of the KPA500 modules combined? 73 Allan GM4ZUK ______________________________________________________________ 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 |
Re: [KPA500] - 144MHz Version?
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Allan G Duncan wrote:
> I was recently studying the schematics of the KPA500 and looked at the > specification of the VRF2933 devices which are used in the RF deck of the > amplifier. I noted that the devices are rated to 150MHz which made me think > a 144Mhz version of the KPA500 would be a nice addition for a K3 equipped > with a K144XV 2m option (or indeed any 144MHz transceiver). If it's goin' to be at 2KW version it'll be mine. Just the 2 cents of an insane moonbouncer... Udo, DK5YA -- ****************************************** Webs by DK5YA: * http://www.mmmonvhf.de/ [editor]* http://www.vhfdx.de/ [owner] * http://www.palekastro.de/ [owner] * http://www.solweb.de/ [owner] * http://www.spessartwetter.de/ [owner] * ****************************************** ______________________________________________________________ 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 |
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In reply to this post by Allan Duncan-4
If a 2-meter version of the KPA500 ever gets to the drawing-board stage,
I'd vote for two-band capability, adding 6 meters; this would be ideal for VHF/UHF contesting, as it would provide a single amp for the two most-used bands in those contests. I think that trying to stretch it to 432 mhz would be a much more difficult design challenge, since it would require more modification to the circuitry than substituting a different power transistor, whereas you might be able to accommodate 2 meters with the existing board layout or something similar. Lew K6LMP On Sep 6, 2011, at 7:48 AM, Allan G Duncan wrote: > I was recently studying the schematics of the KPA500 and looked at the > specification of the VRF2933 devices which are used in the RF deck of the > amplifier. I noted that the devices are rated to 150MHz which made me think > a 144Mhz version of the KPA500 would be a nice addition for a K3 equipped > with a K144XV 2m option (or indeed any 144MHz transceiver). Nearly all the > existing KPA500 metalwork, PSU and front panel PCB (with different firmware > and no band buttons) could be carried over with a different RF deck (perhaps > using the same VRF2933 devices and heatsink). A 2m version could potentially > be lower cost as the switchable complex LPF arrangement of the HF/6M KPA500 > would not be required. The RF deck aside, the R&D costs would be low, using > much of the already proven KPA500 hardware. The 500W output is ideal for > here in the UK where the power limit is 400W. Even a 432Mhz version could be > created although the VRF2933 devices would have to be replaced with > something else - I suspect the demand for this 70cm version would be far > lower than that for 144MHz and would not be cost effective for Elecraft. > > I currently use a Henry Tempo 2002 using two Eimac 8874 on 144MHz. I think > that a 144MHz KPA500 would be cheaper than obtaining two replacement tubes > for my existing amp! I would certainly be very interested in the purchase of > a 144MHz KPA500 (KPAV500 ?) - anyone else? > > On a slightly different matter, I note that the KPA500 front panel PCB > schematic also has an unused "2nd RF deck" connection - perhaps for a future > KPA1000 utilising two of the KPA500 modules combined? > > 73 > > Allan > GM4ZUK > > ______________________________________________________________ > 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 ______________________________________________________________ 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 |
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In reply to this post by Allan Duncan-4
Yes,
I would. Wouldn't require all the space either and would have a little room to spare. Auto tuner for 2m? :-) 73, Bill K9YEQ -----Original Message----- I was recently studying the schematics of the KPA500 and looked at the specification of the VRF2933 devices which are used in the RF deck of the amplifier. I noted that the devices are rated to 150MHz which made me think a 144Mhz version of the KPA500 would be a nice addition for a K3 equipped with a K144XV 2m option (or indeed any 144MHz transceiver). Nearly all the existing KPA500 metalwork, PSU and front panel PCB (with different firmware and no band buttons) could be carried over with a different RF deck (perhaps using the same VRF2933 devices and heatsink). A 2m version could potentially be lower cost as the switchable complex LPF arrangement of the HF/6M KPA500 would not be required. The RF deck aside, the R&D costs would be low, using much of the already proven KPA500 hardware. The 500W output is ideal for here in the UK where the power limit is 400W. Even a 432Mhz version could be created although the VRF2933 devices would have to be replaced with something else - I suspect the demand for this 70cm version would be far lower than that for 144MHz and would not be cost effective for Elecraft. I currently use a Henry Tempo 2002 using two Eimac 8874 on 144MHz. I think that a 144MHz KPA500 would be cheaper than obtaining two replacement tubes for my existing amp! I would certainly be very interested in the purchase of a 144MHz KPA500 (KPAV500 ?) - anyone else? 73 Allan GM4ZUK ______________________________________________________________ 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 |
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In reply to this post by Allan Duncan-4
Me too.
73' Samir, SM7VZX (7s7v) -----Original Message----- Yes, I would. Wouldn't require all the space either and would have a little room to spare. Auto tuner for 2m? :-) 73, Bill K9YEQ -----Original Message----- I was recently studying the schematics of the KPA500 and looked at the specification of the VRF2933 devices which are used in the RF deck of the amplifier. I noted that the devices are rated to 150MHz which made me think a 144Mhz version of the KPA500 would be a nice addition for a K3 equipped with a K144XV 2m option (or indeed any 144MHz transceiver). Nearly all the existing KPA500 metalwork, PSU and front panel PCB (with different firmware and no band buttons) could be carried over with a different RF deck (perhaps using the same VRF2933 devices and heatsink). A 2m version could potentially be lower cost as the switchable complex LPF arrangement of the HF/6M KPA500 would not be required. The RF deck aside, the R&D costs would be low, using much of the already proven KPA500 hardware. The 500W output is ideal for here in the UK where the power limit is 400W. Even a 432Mhz version could be created although the VRF2933 devices would have to be replaced with something else - I suspect the demand for this 70cm version would be far lower than that for 144MHz and would not be cost effective for Elecraft. I currently use a Henry Tempo 2002 using two Eimac 8874 on 144MHz. I think that a 144MHz KPA500 would be cheaper than obtaining two replacement tubes for my existing amp! I would certainly be very interested in the purchase of a 144MHz KPA500 (KPAV500 ?) - anyone else? 73 Allan GM4ZUK ------------------------------ __________ Information from ESET NOD32 Antivirus, version of virus signature database 6438 (20110905) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.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 |
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