KPA500 Combiner
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Those who already have a KPA500 it might be tempted to buy another KPA500
(kit) to get 1 KW output. This would be a 3 db extra signal strength at a cost of approx. $4.20 per watt which would be very expensive. The cost of the combiner would also have to be considered. The combiner with a dummy load and imbalance trip circuit might be feasible to market at approx. $500. ..Well I guess this is too expensive, but it surely would be nice to have a KPA1000 Elecraft linear amplifier. Roy Morris W4WFB ______________________________________________________________ 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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I have to wonder about the rationale of spending anything for that extra
1/2 S-unit. Over the years I have worked most weak-signal modes, including some EME, so I understand there are instances where an extra db can make or break a QSO but I can't imagine that happening often enough on HF to make any difference at all. I'd think it would be far better to invest that $1k+ in aluminum and steel that will positively impact both receiving and transmitting. Jack, W6NF/VE4SNA On 3/3/2014 7:13 AM, Roy Morris wrote: > Those who already have a KPA500 it might be tempted to buy another KPA500 > (kit) to get 1 KW output. This would be a 3 db extra signal strength at a > cost of approx. $4.20 per watt which would be very expensive. The cost of > the combiner would also have to be considered. The combiner with a dummy > load and imbalance trip circuit might be feasible to market at approx. $500. > ..Well I guess this is too expensive, but it surely would be nice to have a > KPA1000 Elecraft linear amplifier. Roy Morris W4WFB > > ______________________________________________________________ > 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 > --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.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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In reply to this post by Roy Morris-6
I think the economical use of a combiner might be on DXpeditions where a
number of other KPA500's might already be in attendance (with different owners). A combiner would allow them to produce a kw on 80/160 (where +3db are most likely to matter) with equipment they already have. John AE5X http://www.ae5x.com/blog Those who already have a KPA500 it might be tempted to buy another KPA500 (kit) to get 1 KW output. This would be a 3 db extra signal strength at a cost of approx. $4.20 per watt which would be very expensive. The cost of the combiner would also have to be considered. The combiner with a dummy load and imbalance trip circuit might be feasible to market at approx. $500. ..Well I guess this is too expensive, but it surely would be nice to have a KPA1000 Elecraft linear amplifier. Roy Morris W4WFB ______________________________________________________________ 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 W6NF
I really don't find those kinds of generalizations very constructive ... or accurate. LOTS of hams live where putting up an additional kilobuck worth of aluminum is out of the question due to space or neighborhood or aesthetic considerations. An extra 3 db of transmit power can make a noticeable difference for them without violating those other considerations, especially if their local noise levels are low on receive. Whether that is worth $1K to them will vary from ham to ham. Besides, for many hams who already have decent antennas on a decent tower, it would probably take considerably more than $1K to get that extra 3 db out of more aluminum. Lastly, if you don't think an extra 3 db can represent a significant improvement on HF, check out http://www.ab7e.com/weak_signal/mdd.html Anybody who is an active contester or DXer on HF will often find that extra 3 db useful in a pileup. 73, Dave AB7E On 3/3/2014 9:14 AM, Jack wrote: > I have to wonder about the rationale of spending anything for that > extra 1/2 S-unit. > > Over the years I have worked most weak-signal modes, including some > EME, so I understand there are instances where an extra db can make or > break a QSO but I can't imagine that happening often enough on HF to > make any difference at all. > > I'd think it would be far better to invest that $1k+ in aluminum and > steel that will positively impact both receiving and transmitting. > > Jack, W6NF/VE4SNA > > On 3/3/2014 7:13 AM, Roy Morris wrote: >> Those who already have a KPA500 it might be tempted to buy another >> KPA500 >> (kit) to get 1 KW output. This would be a 3 db extra signal strength >> at a >> cost of approx. $4.20 per watt which would be very expensive. The >> cost of >> the combiner would also have to be considered. The combiner with a >> dummy >> load and imbalance trip circuit might be feasible to market at >> approx. $500. >> ..Well I guess this is too expensive, but it surely would be nice to >> have a >> KPA1000 Elecraft linear amplifier. Roy Morris W4WFB ______________________________________________________________ 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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My thought is that connecting two standalone amplifiers, each with its
own protective circuits, bias supplies, etc. with a combiner is kludgy and likely to lead to problems. Now the KPA1500 prototype -- that was neat. On 3/3/2014 9:33 AM, David Gilbert wrote: > > I really don't find those kinds of generalizations very constructive ... > or accurate. LOTS of hams live where putting up an additional kilobuck > worth of aluminum is out of the question due to space or neighborhood or > aesthetic considerations. An extra 3 db of transmit power can make a > noticeable difference for them without violating those other > considerations, especially if their local noise levels are low on > receive. Whether that is worth $1K to them will vary from ham to ham. > > Besides, for many hams who already have decent antennas on a decent > tower, it would probably take considerably more than $1K to get that > extra 3 db out of more aluminum. > > Lastly, if you don't think an extra 3 db can represent a significant > improvement on HF, check out http://www.ab7e.com/weak_signal/mdd.html > Anybody who is an active contester or DXer on HF will often find that > extra 3 db useful in a pileup. > > 73, > Dave AB7E -- 73, Vic, K2VCO Fresno CA http://www.qsl.net/k2vco/ ______________________________________________________________ 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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Or you could run the outputs to separate antennas
for some really interesting results :-) Phil, w7ox On 3/3/14, 9:39 AM, Vic Rosenthal K2VCO wrote: > My thought is that connecting two standalone > amplifiers, each with its own protective > circuits, bias supplies, etc. with a combiner is > kludgy and likely to lead to problems. > > Now the KPA1500 prototype -- that was neat. > > On 3/3/2014 9:33 AM, David Gilbert wrote: >> >> I really don't find those kinds of >> generalizations very constructive ... >> or accurate. LOTS of hams live where putting >> up an additional kilobuck >> worth of aluminum is out of the question due to >> space or neighborhood or >> aesthetic considerations. An extra 3 db of >> transmit power can make a >> noticeable difference for them without >> violating those other >> considerations, especially if their local noise >> levels are low on >> receive. Whether that is worth $1K to them >> will vary from ham to ham. >> >> Besides, for many hams who already have decent >> antennas on a decent >> tower, it would probably take considerably more >> than $1K to get that >> extra 3 db out of more aluminum. >> >> Lastly, if you don't think an extra 3 db can >> represent a significant >> improvement on HF, check out >> http://www.ab7e.com/weak_signal/mdd.html >> Anybody who is an active contester or DXer on >> HF will often find that >> extra 3 db useful in a pileup. >> >> 73, >> Dave AB7E > > ______________________________________________________________ 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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I find a StackMatch appropriate for that.
73 de Dick, K6KR -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Phil Wheeler Sent: Monday, March 03, 2014 10:13 AM To: [hidden email] Subject: Re: [Elecraft] KPA500 Combiner Or you could run the outputs to separate antennas for some really interesting results :-) Phil, w7ox On 3/3/14, 9:39 AM, Vic Rosenthal K2VCO wrote: > My thought is that connecting two standalone amplifiers, each with its > own protective circuits, bias supplies, etc. with a combiner is kludgy > and likely to lead to problems. > > Now the KPA1500 prototype -- that was neat. > > On 3/3/2014 9:33 AM, David Gilbert wrote: >> >> I really don't find those kinds of >> generalizations very constructive ... >> or accurate. LOTS of hams live where putting up an additional >> kilobuck worth of aluminum is out of the question due to space or >> neighborhood or >> aesthetic considerations. An extra 3 db of >> transmit power can make a >> noticeable difference for them without violating those other >> considerations, especially if their local noise levels are low on >> receive. Whether that is worth $1K to them will vary from ham to >> ham. >> >> Besides, for many hams who already have decent antennas on a decent >> tower, it would probably take considerably more than $1K to get that >> extra 3 db out of more aluminum. >> >> Lastly, if you don't think an extra 3 db can represent a significant >> improvement on HF, check out http://www.ab7e.com/weak_signal/mdd.html >> Anybody who is an active contester or DXer on HF will often find that >> extra 3 db useful in a pileup. >> >> 73, >> Dave AB7E > > ______________________________________________________________ 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 Vic Rosenthal
Vic,
The problems would not be frightful if the amplifiers are of a same model and the combiner is designed to withstand to 5-10% difference between the amplifiers outputs. Anyway, combining 2-3 KPA500 makes no much sense for me, but if you need a 5kW auto tune amplifier (not for a ham use of course), you may find it more expensive than 3 pcs ACOM 2000A and the due combiner. 73, Val LZ1VB > My thought is that connecting two standalone amplifiers, each with > its own protective circuits, bias supplies, etc. with a combiner is > kludgy and likely to lead to problems. > > Now the KPA1500 prototype -- that was neat. > > On 3/3/2014 9:33 AM, David Gilbert wrote: >> >> I really don't find those kinds of generalizations very >> constructive ... >> or accurate. LOTS of hams live where putting up an additional >> kilobuck >> worth of aluminum is out of the question due to space or >> neighborhood or >> aesthetic considerations. An extra 3 db of transmit power can >> make a >> noticeable difference for them without violating those other >> considerations, especially if their local noise levels are low on >> receive. Whether that is worth $1K to them will vary from ham to >> ham. >> >> Besides, for many hams who already have decent antennas on a decent >> tower, it would probably take considerably more than $1K to get >> that >> extra 3 db out of more aluminum. >> >> Lastly, if you don't think an extra 3 db can represent a >> significant >> improvement on HF, check out >> http://www.ab7e.com/weak_signal/mdd.html >> Anybody who is an active contester or DXer on HF will often find >> that >> extra 3 db useful in a pileup. >> >> 73, >> Dave AB7E > > > -- > 73, > > Vic, K2VCO > Fresno CA > http://www.qsl.net/k2vco/ > > 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 Vic Rosenthal
There is a market for a 1,000 or 1,500 watt Solid State Amp, with
Autotuner, that covers 160 through 6 and doesn't cost $10 Grand. You could sell a lot of them if they were priced at $4K or under. With todays LDMOS devices, that is a doable target price. 73, Dick, W1KSZ On 3/3/2014 10:39 AM, Vic Rosenthal K2VCO wrote: > My thought is that connecting two standalone amplifiers, each with its > own protective circuits, bias supplies, etc. with a combiner is kludgy > and likely to lead to problems. > > Now the KPA1500 prototype -- that was neat. > > On 3/3/2014 9:33 AM, David Gilbert wrote: >> >> I really don't find those kinds of generalizations very constructive ... >> or accurate. LOTS of hams live where putting up an additional kilobuck >> worth of aluminum is out of the question due to space or neighborhood or >> aesthetic considerations. An extra 3 db of transmit power can make a >> noticeable difference for them without violating those other >> considerations, especially if their local noise levels are low on >> receive. Whether that is worth $1K to them will vary from ham to ham. >> >> Besides, for many hams who already have decent antennas on a decent >> tower, it would probably take considerably more than $1K to get that >> extra 3 db out of more aluminum. >> >> Lastly, if you don't think an extra 3 db can represent a significant >> improvement on HF, check out http://www.ab7e.com/weak_signal/mdd.html >> Anybody who is an active contester or DXer on HF will often find that >> extra 3 db useful in a pileup. >> >> 73, >> Dave AB7E > > ______________________________________________________________ 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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