K1 Low power
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Ok first let me this is the same K1 from earlier. The 40m portion works just fine with 6ish watts out. Heck I even had one QSO to break it in.Now for the 20m, I did the alignments and can only get 2.5 watts out. Tried and tried again to align it and can only get around 2.5 watts. It is getting late for me tonight and I have to work tomorrow so I will tackle it again tomorrow. Any Ideas?
Thanks Rick/WA6ES |
Re: K1 Low power, Suggestion to increase output power
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Hello Rick,
HNY2010. When I had output power problems at 15m, not at 20m, I increased the output power by 'tuning' the low pass output filter (L9/L10, L11/L12), suggested by ELECRAFT. By bringing windings together I was able to get the required output. It does not look as nice when having the windings evenly spread, but in the end the output power is more important. Make sure you have a dummy load when checking Pout, as when VSWR is poor, depending of the COAX length you will see high or low max output power on display K1. Reason: K1 is measuring Vpeak out, and calculates it back to power. So reading on display is only reliable when you have 50ohm, or have installed the internal antenna tuner. Also make sure you have 13.8V, Pout max between 12V and 13.8V makes a difference. I run it at 12V, Power is 5W at 15m/20m band, while running at 13.8V I can easily get up to 7Watt. For me 12V is fine. If tuning of the coils does not work, contact elecraft support, and refer to power problems from PE1FJN October this year at 15m SN: 2761. I changed 1 resistor on instructions from ELECRAFT. At this moment I have now no access to this mail(sorry), but I'm sure you will be able to get the same instructions. Having changed this resistor power was very fine, and not marginal anymore. Hope this helps, 73 PE1FJN Marc K1 SN:2761 PS: Good Luck, at 20m DX is really nice with this RIG. |
Re: K1 Low power, Suggestion to increase output power
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Marc
Well I worked on the winding spacing and got it up to a little over 4 watts, actually 4.4, so that did help. I sent off an email to Elecraft yesterday when I posted this and no answer yet, maybe I will call them and talk to Scott there. I have to get a couple of speaker slides, heck those things are small! I even played with the 40m section and got another watt out there also! Can I live with 4.4 watts on 20,maybe, but if I get more pwr out, even better. Thanks again for the info Rick/WA6ES K1 SN:2820
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Re: K1 Low power, Suggestion to increase output power
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Rick,
What is your power supply voltage? The K1 maximum output is quite dependent on the supply voltage, so if you are using 12 volts instead of 13.8 volts, that may explain your 4.4 watt power output limit. 73, Don W3FPR Rick/WA6ES wrote: > Marc > Well I worked on the winding spacing and got it up to a little over 4 > watts, actually 4.4, so that did help. I sent off an email to Elecraft > yesterday when I posted this and no answer yet, maybe I will call them and > talk to Scott there. I have to get a couple of speaker slides, heck those > things are small! I even played with the 40m section and got another watt > out there also! > Can I live with 4.4 watts on 20,maybe, but if I get more pwr out, even > better. > > Thanks again for the info > Rick/WA6ES > > > 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: K1 Low power, Suggestion to increase output power
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Hi Don
13.8v. I get 7 watts on 40m and just want a little more for 20m. I am happy with the little thing. Actually I was switching between my ft817 and the K1. Maybe it is me but the K1 heard a little better. Or maybe it is just me that I made the K1 Rick/WA6ES K1 SN:2820
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Re: K1 Low power, Suggestion to increase output power
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In reply to this post by Rick/WA6ES
On Jan 4, 2010, at 9:02 PM, Rick/WA6ES wrote:
> Well I worked on the winding spacing and got it up to a little over 4 watts, actually 4.4, so that did help. How are you measuring the power output? With my new K1 using a DL1 and KAT1 I get exactly the number of bars on the TX LCD bar graph as I set in the output menu for power output using a 13.8 vold power supply, from 2 to 7. This is true for all 4 bands, with the only difference being if I don't tune it takes a few CQ's for the KAT1 to catch up, as expected. Just curious what I might be missing, Byron KI6NUL ______________________________________________________________ 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: K1 Low power, Suggestion to increase output power
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In reply to this post by Rick/WA6ES
Rick,
Thanks for that clarification on the supply voltage. Yes, in most cases, the K1 will hear better than the FT-817. You should be able to have 5 watts or more on 20 meters with that supply voltage. You said you made some improvement by squeezing the turns on the LPF, so the LPF may be your only problem. Re-count the turns on the 20 meter LPF toroids - count the number of times the wire passes through the center of the core. If you have an antenna analyzer, I can tell you how to set-up to check the LPF cutoff frequency as a check. 73, Don W3FPR Rick/WA6ES wrote: > Hi Don > 13.8v. I get 7 watts on 40m and just want a little more for 20m. I am > happy with the little thing. Actually I was switching between my ft817 and > the K1. Maybe it is me but the K1 heard a little better. Or maybe it is just > me that I made the K1 > > Rick/WA6ES > K1 SN:2820 > > > Don Wilhelm-4 wrote: > >> Rick, >> >> What is your power supply voltage? The K1 maximum output is quite >> dependent on the supply voltage, so if you are using 12 volts instead of >> 13.8 volts, that may explain your 4.4 watt power output limit. >> >> 73, >> Don W3FPR >> >> Rick/WA6ES wrote: >> >>> Marc >>> Well I worked on the winding spacing and got it up to a little over 4 >>> watts, actually 4.4, so that did help. I sent off an email to Elecraft >>> yesterday when I posted this and no answer yet, maybe I will call them >>> and >>> talk to Scott there. I have to get a couple of speaker slides, heck those >>> things are small! I even played with the 40m section and got another watt >>> out there also! >>> Can I live with 4.4 watts on 20,maybe, but if I get more pwr out, even >>> better. >>> >>> Thanks again for the info >>> Rick/WA6ES >>> >>> >>> >>> >> ______________________________________________________________ >> 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 >> >> >> > > > ------------------------------------------------------------------------ > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 9.0.725 / Virus Database: 270.14.124/2599 - Release Date: 01/04/10 03:24:00 > > 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: K1 Low power, Suggestion to increase output power
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In reply to this post by Byron N6NUL
Byron
I am using the meter on the K1. I also have an MFJ Tuner/meter combo for QRP that is not that accurate. I will be purchasing a new meter soon. Not sure about the KAT1 issue, that is my next purchase along with the Battery pack. Maybe Don/W3FPR could help answer this. Don Yes please tell me how to read the cut off Freq. I have the MFJ type. Thanks Rick/WA6ES
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RE: K1 Low power, Suggestion to increase output power
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In reply to this post by Rick/WA6ES
Hello Rick, I’m glad I could help. It seems you are very close to closing the box, and making 1st CW
QSO with the K1. If you have the antenna connected and the band is open, we can
try to set a sked, so I can contact Long Beach(just checked QRZ.com). My lot is small as well, and my main antenna is a WIMO GP with
radials for 15m/20m, and now it is cold I have installed in-house below the
roof an inverted V, loaded with coals to make it fit below the roof. Anyway, good luck with the K1, I made so far in~3 months >50
CW QSO’s, worked many new countries, it’s really fun, and so nice quit to
listen through the 200Hz filter. The nicest contact so far was VK4. Good DX, 73 Marc Van: Rick/WA6ES [via
Elecraft] [mailto:[hidden email]] Marc Marc PE1FJN wrote: Hello Rick, View message @ http://n2.nabble.com/K1-Low-power-tp4248493p4253616.html
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Re: K1 Low power, Suggestion to increase output power
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In reply to this post by Rick/WA6ES
Rick,
Certainly - to measure any LPF, here is how to do it, along with the K1 band board pin information: In general, you just isolate the LPF, terminate one side and scan the other side with the antenna analyzer. Conceptually it is easy. What gets complicated is how to isolate the LPF - it differs from one radio to another. For the K1, you must remove the band board AFTER setting the band to the one to be scanned - fortunately there are latching relays. After the band board is removed, connect a 51 ohm resistor between pins 2 and 3 of P3 - then devise a means of connecting the antenna analyzer to pin 9 (or 10) of J2 and ground. Making those connections will depend on what one has in the shack - certainly the resistor could be soldered to the solder side of P3 and a short piece of coax (inches long) can be soldered onto the solder side of J2, but there are other means if one has some header material lying around to make up a temporary fixture that can simply be plugged to the board. Having made the connections, then the analyzer is scanned over the band of interest observing the SWR - it should be low, and should climb as the frequency is increased above the band, and should be quite high at the 2nd harmonic of the lower band edge. For the KAT1, it includes a wattmeter, but that must be calibrated to read the correct power - the K1 uses the wattmeter output to control the actual output power, so it is natural that the K1 LCD bargraph agrees with the OUT setting. You can calibrate the wattmeter simply by making it match whatever external wattmeter you have, or use something more accurate, like the detector on the Elecraft DL1. Be aware that there is a lot of discrepancy in wattmeter readings, and I don't trust many of them until they have proven their accuracy. I do have several tools that can be used for that task, but my most basic 'instrument' is a known good 50 ohm dummy load that is flat over the frequency range to be used. I read the RF voltage across the dummy load with my oscilloscope and a 10X probe, then compute the power - it is quick and easy because the 'scope reads peak to peak RF voltage and the formula for power reduces to V^2/8*R or V^2/400 for a 50 ohm load - easy and quick to punch the numbers in on a calculator. I have posted that formula derivation on the reflector before, so now if anyone wants to check it, you can derive your own or check the archives - Hint: use the exact expression sqrt2/2 when reducing the formula for RMS conversion, if you try it with 0.707 you will go nuts (the sqrt2 terms drop out when the formula is reduced). 73, Don W3FPR Rick/WA6ES wrote: > Byron > I am using the meter on the K1. I also have an MFJ Tuner/meter combo for > QRP that is not that accurate. I will be purchasing a new meter soon. Not > sure about the KAT1 issue, that is my next purchase along with the Battery > pack. Maybe Don/W3FPR could help answer this. > > Don > Yes please tell me how to read the cut off Freq. I have the MFJ type. > > Thanks > Rick/WA6ES > > > Byron Servies-2 wrote: > >> On Jan 4, 2010, at 9:02 PM, Rick/WA6ES wrote: >> >> How are you measuring the power output? >> >> With my new K1 using a DL1 and KAT1 I get exactly the number of bars on >> the TX LCD bar graph as I set in the output menu for power output using a >> 13.8 vold power supply, from 2 to 7. This is true for all 4 bands, with >> the only difference being if I don't tune it takes a few CQ's for the KAT1 >> to catch up, as expected. >> >> Just curious what I might be missing, >> >> Byron KI6NUL >> > 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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