K3 Power out
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Firstly
Got the K3 assembled. The transverter board was back ordered and so is the subreceiver so I will be re entering the K3 and adding to it at least twice over the next few months. I'm not looking forward to the disassembly & re-assembly but doing the kit sure gave me a great appreciation for the detail and function this marvelous radio has. Absolutely amazing. Kudos Wane & Eric, you surely have an amazing way of looking at things. Most effective and clear. With that there are a few questions but in the spirit of one at a time; The power supply I have been using in the setup is a Heathkit Power supply which was made for one of their last Transceivers. It's a HP- 1144 and offers 20 Amps out. After calibrating the K3 I tried getting 120 watts out to the dummy load but after the 50 watt calibration, when I held tune down to see how it read. I only got 102-105W out, not 120, though I set he power out at 120W. I'm wondering if the Heath power supply is lacking and that's the reason for the lower maximum output? It seemed to work well as a backup for the Omni V & corsair. Idears? Thanks Gary (One year older as of yesterday...) _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Gary Smith
I got following data with IFR AM/FM 1600:
K3 sn1302 POWER SET(W) POWER OUT（W) Difference ERR(%) 0 0.15 0.15 0.1 0.15 0.05 50.00% 0.2 0.3 0.1 50.00% 0.3 0.31 0.01 3.33% 0.4 0.4 0 0.00% 0.5 0.51 0.01 2.00% 0.6 0.63 0.03 5.00% 0.7 0.69 -0.01 -1.43% 0.8 0.76 -0.04 -5.00% 0.9 0.83 -0.07 -7.78% 1 1 0 0.00% 2 2.1 0.1 5.00% 3 3.2 0.2 6.67% 4 4.2 0.2 5.00% 5 5 0 0.00% 6 5.8 -0.2 -3.33% 7 6.6 -0.4 -5.71% 8 7.7 -0.3 -3.75% 9 8.8 -0.2 -2.22% 10 9.7 -0.3 -3.00% 12 11.4 -0.6 -5.00% 14 15.8 1.8 12.86% 16 17.5 1.5 9.38% 18 19.7 1.7 9.44% 20 21.8 1.8 9.00% 22 24 2 9.09% 24 25.5 1.5 6.25% 26 27.7 1.7 6.54% 28 29.3 1.3 4.64% 30 30.8 0.8 2.67% 32 33.3 1.3 4.06% 34 35.1 1.1 3.24% 36 37 1 2.78% 38 38.9 0.9 2.37% 40 40.5 0.5 1.25% 42 42 0 0.00% 44 44 0 0.00% 46 46 0 0.00% 48 48 0 0.00% 50 50.5 0.5 1.00% 55 54 -1 -1.82% 60 59 -1 -1.67% 65 63 -2 -3.08% sorry, no over 65w data because no bigger PS in lab. All the best! David BA4RF On Sun, Dec 21, 2008 at 1:03 PM, Gary Smith <[hidden email]> wrote: Firstly _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by AC7AC
Ron
A crowbar circuit is used to "disable" the power supply in the event of over voltage. The current limit is what would limit the current output of a power supply. A typical crowbar circuit uses a SCR triggered by a voltage sensor. The SCR conducts and shorts the output of the supply. Which in turn puts it into current limit mode and decreases the output voltage to near zero. And yes, a 20 amp supply is marginal for a 100 watt HF rig because of the examples you have given. The 20 amp Astron can be fudged a little bit by increasing the current limit to around 22 amps. The modification involves adding a resistor to the current limit circuit of the 723 regulator. 73 and Merry Christmas to all! Jim W7RY ----- Original Message ----- From: "Ron D'Eau Claire" <[hidden email]> To: <[hidden email]>; <[hidden email]> Sent: Saturday, December 20, 2008 9:40 PM Subject: RE: [Elecraft] K3 Power out > Hello Gary, and congratulations! Opening up the K3 again is not nearly as > traumatic as you might think. > > The POWER control will *ask* for more than the rig can deliver. It's > spec'd > at 100 watts, and that's what is guaranteed. The K3 can make a bit more > than > 100 watts on most bands, but that's all it's spec'd to do. When you set > the > POWER control for a specific output, it tries to adjust the transmitter > circuits for that output, but can't do it if it's out of their range. > That's > what is happening to you at 120 watts. > > The absolute maximum power will vary by band and to some extent from rig > to > rig. But since 120 watts is a whole 0.8 dB more than 100 watts, it's not > significant on the air. > > You're probably crowding that 20 amp supply at 100 watts on some bands. > The > efficiency (and so the current required for a given output power) varies > from band to band. I'm running a K3 with a 20 amp supply, but I'm near the > limit on some bands at right on 20 amps for 100 watts out, if the SWR is > quite low. (Higher SWR's reduce the efficiency so the current goes up!) > > I don't know whether your supply has a crowbar circuit in it, but my > Astron > does. It lets me know if I push too hard by simply shutting down. I have > to > cycle the power supply mains switch to reset it, then turn the K3 on > again. > > Ron AC7AC > > > > > > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of Gary Smith > Sent: Saturday, December 20, 2008 9:04 PM > To: [hidden email] > Subject: [Elecraft] K3 Power out > > Firstly > > Got the K3 assembled. The transverter board was back ordered and so > is the subreceiver so I will be re entering the K3 and adding to it > at least twice over the next few months. I'm not looking forward to > the disassembly & re-assembly but doing the kit sure gave me a great > appreciation for the detail and function this marvelous radio has. > Absolutely amazing. > > Kudos Wane & Eric, you surely have an amazing way of looking at > things. Most effective and clear. > > With that there are a few questions but in the spirit of one at a > time; > > The power supply I have been using in the setup is a Heathkit Power > supply which was made for one of their last Transceivers. It's a HP- > 1144 and offers 20 Amps out. > > After calibrating the K3 I tried getting 120 watts out to the dummy > load but after the 50 watt calibration, when I held tune down to see > how it read. I only got 102-105W out, not 120, though I set he power > out at 120W. I'm wondering if the Heath power supply is lacking and > that's the reason for the lower maximum output? It seemed to work > well as a backup for the Omni V & corsair. > > Idears? > > Thanks > Gary > (One year older as of yesterday...) > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by AC7AC
After measuring the TX IMD on SSB I stopped putting the
radio above 100W. IMO the K3 should be limited to 100W, it is sad to see it isn´t. My advice would be, on SSB never go above 199W, on CW it doesn´t matter. Please Elecraft, make a FW change and limit the radio to 100W, thanks! / Jim SM2EKM --------------------------- Ron D'Eau Claire wrote: > Hello Gary, and congratulations! Opening up the K3 again is not nearly as > traumatic as you might think. > > The POWER control will *ask* for more than the rig can deliver. It's spec'd > at 100 watts, and that's what is guaranteed. The K3 can make a bit more than > 100 watts on most bands, but that's all it's spec'd to do. When you set the > POWER control for a specific output, it tries to adjust the transmitter > circuits for that output, but can't do it if it's out of their range. That's > what is happening to you at 120 watts. > > The absolute maximum power will vary by band and to some extent from rig to > rig. But since 120 watts is a whole 0.8 dB more than 100 watts, it's not > significant on the air. > > You're probably crowding that 20 amp supply at 100 watts on some bands. The > efficiency (and so the current required for a given output power) varies > from band to band. I'm running a K3 with a 20 amp supply, but I'm near the > limit on some bands at right on 20 amps for 100 watts out, if the SWR is > quite low. (Higher SWR's reduce the efficiency so the current goes up!) > > I don't know whether your supply has a crowbar circuit in it, but my Astron > does. It lets me know if I push too hard by simply shutting down. I have to > cycle the power supply mains switch to reset it, then turn the K3 on again. > > Ron AC7AC > > > > > > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of Gary Smith > Sent: Saturday, December 20, 2008 9:04 PM > To: [hidden email] > Subject: [Elecraft] K3 Power out > > Firstly > > Got the K3 assembled. The transverter board was back ordered and so > is the subreceiver so I will be re entering the K3 and adding to it > at least twice over the next few months. I'm not looking forward to > the disassembly & re-assembly but doing the kit sure gave me a great > appreciation for the detail and function this marvelous radio has. > Absolutely amazing. > > Kudos Wane & Eric, you surely have an amazing way of looking at > things. Most effective and clear. > > With that there are a few questions but in the spirit of one at a > time; > > The power supply I have been using in the setup is a Heathkit Power > supply which was made for one of their last Transceivers. It's a HP- > 1144 and offers 20 Amps out. > > After calibrating the K3 I tried getting 120 watts out to the dummy > load but after the 50 watt calibration, when I held tune down to see > how it read. I only got 102-105W out, not 120, though I set he power > out at 120W. I'm wondering if the Heath power supply is lacking and > that's the reason for the lower maximum output? It seemed to work > well as a backup for the Omni V & corsair. > > Idears? > > Thanks > Gary > (One year older as of yesterday...) _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Sorry made a typo. 199W should be 100W.
Jan Erik Holm wrote: > After measuring the TX IMD on SSB I stopped putting the > radio above 100W. > IMO the K3 should be limited to 100W, it is sad to see > it isn´t. > My advice would be, on SSB never go above 199W, on CW > it doesn´t matter. > Please Elecraft, make a FW change and limit the radio > to 100W, thanks! > > / Jim SM2EKM _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Jan Erik Holm
Jan Erik Holm wrote:
> Please Elecraft, make a FW change and limit the radio > to 100W, thanks! Human nature being what it is, the likely result of this would be a large number of people refusing to upgrade their firmware any further and a significant grapevine message about how new purchasers can get increased power by downgrading the firmware. There is quite a significant lobby on this list for the radio to impose no restrictions in firmware. -- David Woolley "The Elecraft list is a forum for the discussion of topics related to Elecraft products and more general topics related ham radio" List Guidelines <http://www.elecraft.com/elecraft_list_guidelines.htm> _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Jan Erik Holm
Jim try setting your power supply so you have 13.8-14.0V key down at maximum power and see if that helps the IMD some. 73, Bill |
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OK that could be done, I will experiment further when
I do get some time. I know I have checked the PS voltage but dont remember what it was, have to go down into the basement and check. Now checked, it´s 13.88 at 100W and 13.84V at 120W. IMD comes up 8dB at 120W compared with 100W. Stays pritty much flat betwen 10-100W. At 100W K3 is about 10 dB worse then a FT-1000D at full 200W. And for kicks a Collins KWM-2 is 10 dB better then the FT-1000D. What I measure is the fully modulated envelope and scan 10 kHz up/dwn from center frequency. That is, what interests me is how the radios looks 5 kHz up/down from center frequency, i e adjacent channel IMD if I call it that. If I would have been the designer I would never have allowed above 100W PEP SSB, CW of course is OK. Merry Christmas / Jim ---------------------------- Bill W4ZV wrote: > > > Jan Erik Holm wrote: >> After measuring the TX IMD on SSB I stopped putting the >> radio above 100W. >> > > Jim try setting your power supply so you have 13.8-14.0V key down at maximum > power and see if that helps the IMD some. > > 73, Bill > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Jim W7RY
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In reply to this post by David Woolley (E.L)
David Woolley (E.L) wrote:
> Jan Erik Holm wrote: > >> Please Elecraft, make a FW change and limit the radio >> to 100W, thanks! > > Human nature being what it is, the likely result of this would be a > large number of people refusing to upgrade their firmware any further > and a significant grapevine message about how new purchasers can get > increased power by downgrading the firmware. > > There is quite a significant lobby on this list for the radio to > impose no restrictions in firmware. > enabled? It might satisfy both camps: those who want to get reminders not to do stuff they don't want to do, and those who to retain as much control as possible locally. Leigh/WA5ZNU _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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