K2 working on 40M
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Hi all,
In case anyone's interested, I got through with test and alignment II on my K2 last night. Everything seemed to proceed normally. Again, I didn't seem to run into any trouble. My first kit and all I'm expecting to have busted something but so far all OK (even the install of L33 hi hi). Maybe I'll mess something up putting in the transmitter and the rest of the RX in the next build phase, who knows hi. I do need to redo the filter calibration tho, as I didn't get them setup the way I want or record any values. And I'm definitely going to have to add the noise blanker if I have any hope of using the rig at home. The line noise is unbelievable here hi! So that'll be my first project after finishing the rig itself I guess.... On to build phase III.... LS |
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Congratulations on your success. I remember how excited I was last year when I powered up my K2 and was able to receive signals on 40m. Just take your time and you will be rewarded with a wonderful radio. There are a ton of parts on the RF board, but the each get added one at a time. Double check each parts value and solder joints and it should work the first time. Have fun, Fred, KC9QQ |
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In reply to this post by lstavenhagen
I'll add hearty congratulations as well. L33 is indeed the tricky part (don't ask me how I know, but Don's advice to re-heat suspicious solder joints comes to mind) and you've done well to leap this hurdle. You'll be golden from here on!
73, Mike K8CN
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In reply to this post by lstavenhagen
Congrats on the K2 receiving on 40. It's only a month or so back that I finished mine so easy for me to remember the thrill of hitting the switch and having it come up working. I used mine on cw for a week or so then went on to the ssb board which allows digital modes as well as phone. Still using it qrp here and may never buy and build the power amp as I have been having a blast with it even on qrp.
If you chose the ssb option perhaps you will find as I did that the directions for setting up the filters are somewhat confusing however it will all fall into place eventually. Cheerio, maybe hear you on the air sometime. 72 Garry/Ve7ajj |
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Garry and all - at least those who are building new K2s.
Yes, the filter setup is a bit "tricky", especially when using filter widths wider than 1.00 kHz. The reason is in the varactors that have shipped with the more recent K2 kits. What that means is that a filter width that is indicates as 2.00 kHz wide on the K2 may actually be 2.5 kHz wide (this is not exact, it all depends on the varactors). The result of this is that the LSB filter settings listed in the manual will be about right, but the USB settings will be way off. In other words, the manual settings will give you a workable filter for the lower sideband response, but will not work for the upper sideband (USB, RTTYr, and CWr) settings. (NOTE: the OP1 filter width is not affected by the varactors - there are no varactors on the KSB2 board). The only cure I know is to use Spectrogram or another audio spectrum analyzer to measure the actual width of the filter (in LSB or CW - not CWr - or RTTY - not RTTYr). When you use LSB, CW or RTTY, you should be on the lower sideband, and you can change the width without much movement of the lower end of the passband frequency. After getting the filer width as you like it, then refine the low frequency end of the lower sideband filter (by changing the BFO setting) and then set the USB BFOs to properly place the sideband. If you want specifics on how to set the filters, look at part 3 of the article on K2 Dial Calibration at my website www.w3fpr.com (while you are there, you may just want to go through the entire K2 Dial Calibration procedure which includes adusting the filters. I have not yet updated the webpage information to include how to handle this "varactor problem", but since you can see the passband width on the Spectrogram display, it should be obvious. Just adjust the width of the filter until the actual width is what you want, and use the K2 display only as a relative indicator. 73, Don W3FPR 2rGarry wrote: > Congrats on the K2 receiving on 40. It's only a month or so back that I > finished mine so easy for me to remember the thrill of hitting the switch > and having it come up working. I used mine on cw for a week or so then went > on to the ssb board which allows digital modes as well as phone. Still > using it qrp here and may never buy and build the power amp as I have been > having a blast with it even on qrp. > > If you chose the ssb option perhaps you will find as I did that the > directions for setting up the filters are somewhat confusing however it will > all fall into place eventually. > > Cheerio, maybe hear you on the air sometime. > > 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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Ok, thanks for the info gentlemen.
I finally ran out of capacitors and resistors last night (thank goodness!) and seem to be in the last stages of building the transmitter and low pass filters for the rest of the bands. So I guess it's getting close to being done. Need to resist the urge to rush now hi hi! Fortunately for the 4.00 mhz oscillator adjustment I have my 706MKIIG which is pretty well calibrated via WWV over the years I've owned it, so I have been able to get it pretty close there. I may have a go with it again when the rig is done using the methods posted on Don's website. Mine is CW only and will stay that way so just the CW filter adjustment is all I think I'll have to go through. I think I got it pretty close with the suggested values in the manual in the section on filter setup. The NB module I'm probably going to order today and I'm now strongly kicking the idea around of getting the internal antenna tuner. Those should still keep me busy for a while. Tnx es 73, LS W5QD |
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In reply to this post by Don Wilhelm-4
Thank you Don. I think the most confusing part of all was, I was
looking for various width settings for the ssb filters. Eventually I came to realize that I had to use the other filters for reduced bandwidth for ssb. After that dawned on me it was relatively easy. Or perhaps I still have not got it correct. Still can't get the display on frequency. I guess I need a decent freq counter. Can't seem to manage with wwv. cheerio and 73. Garry On Thu, Feb 11, 2010 at 8:52 PM, Don Wilhelm-4 [via Elecraft] <[hidden email]> wrote: > Garry and all - at least those who are building new K2s. > > Yes, the filter setup is a bit "tricky", especially when using filter > widths wider than 1.00 kHz. The reason is in the varactors that have > shipped with the more recent K2 kits. What that means is that a filter > width that is indicates as 2.00 kHz wide on the K2 may actually be 2.5 > kHz wide (this is not exact, it all depends on the varactors). The > result of this is that the LSB filter settings listed in the manual will > be about right, but the USB settings will be way off. In other words, > the manual settings will give you a workable filter for the lower > sideband response, but will not work for the upper sideband (USB, RTTYr, > and CWr) settings. (NOTE: the OP1 filter width is not affected by the > varactors - there are no varactors on the KSB2 board). > > The only cure I know is to use Spectrogram or another audio spectrum > analyzer to measure the actual width of the filter (in LSB or CW - not > CWr - or RTTY - not RTTYr). When you use LSB, CW or RTTY, you should > be on the lower sideband, and you can change the width without much > movement of the lower end of the passband frequency. After getting the > filer width as you like it, then refine the low frequency end of the > lower sideband filter (by changing the BFO setting) and then set the USB > BFOs to properly place the sideband. > > If you want specifics on how to set the filters, look at part 3 of the > article on K2 Dial Calibration at my website www.w3fpr.com (while you > are there, you may just want to go through the entire K2 Dial > Calibration procedure which includes adusting the filters. > I have not yet updated the webpage information to include how to handle > this "varactor problem", but since you can see the passband width on the > Spectrogram display, it should be obvious. Just adjust the width of the > filter until the actual width is what you want, and use the K2 display > only as a relative indicator. > > 73, > Don W3FPR > > 2rGarry wrote: >> Congrats on the K2 receiving on 40. It's only a month or so back that I >> finished mine so easy for me to remember the thrill of hitting the switch >> and having it come up working. I used mine on cw for a week or so then >> went >> on to the ssb board which allows digital modes as well as phone. Still >> using it qrp here and may never buy and build the power amp as I have been >> having a blast with it even on qrp. >> >> If you chose the ssb option perhaps you will find as I did that the >> directions for setting up the filters are somewhat confusing however it >> will >> all fall into place eventually. >> >> Cheerio, maybe hear you on the air sometime. >> >> > ______________________________________________________________ > 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 > > > ________________________________ > View message @ http://n2.nabble.com/K2-working-on-40M-tp4554916p4559453.html > To unsubscribe from Re: K2 working on 40M, click here. > |
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In reply to this post by lstavenhagen
LS,
Great progress. Congratulations. Make note that the 4.000 MHz reference oscillator setting that is correct may differ slightly from exactly 4.000 MHz - so don't exhaust too much effort on getting it 'right on' using any kind of measuring device - there is a better way. After you have your K2 finished, use the "N6KR" method (by Wayne Burdick himself) to set the reference oscillator precisely - it requires only the internal counter probe and the ability to receive a known frequency (like WWV at 10 MHz or 15 MHz) on the K2. I could not find the not locate the document on the Elecraft website a few minutes ago, but it is preserved on my website - see http://www.w3fpr.com/n6kr_method.htm for the content of Wayne's original reflector post. While you are going to that trouble, why not do the entire job of calibrating the K2 dial reading. For full information on how to accomplish that as well as supplimental information on setting the K2 filters, look at the atricle on my website www.w3fpr.com dealing with Setting the K2 Dial Calibration - the whole procedure is explained there including the use of Spectrogram. The full explanation take longer to read than to actually do it - walk through the steps once and the second time it will be easy. 73, Don W3FPR lstavenhagen wrote: > Fortunately for the 4.00 mhz oscillator adjustment I have my 706MKIIG which > is pretty well calibrated via WWV over the years I've owned it, so I have > been able to get it pretty close there. I may have a go with it again when > the rig is done using the methods posted on Don's website. > > Mine is CW only and will stay that way so just the CW filter adjustment is > all I think I'll have to go through. I think I got it pretty close with the > suggested values in the manual in the section on filter setup. > > 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 2rGarry
Garry,
You don't need WWV to do the "N6KR" method - you can use any reference signal of known frequency and accuracy. Subtract the BFO frequency from the VFO frequency and that should be the frequency of your reference - if it is not, then adjust C22 until that condition is true.. With WWV (or any other signal on a xxx0.00 frequency), the math is easy and one needs only to match the 3 low order digits in the K2 display. Note - do not attempt to use 15 meters and above - the VFO and BFO are additive on those bands. 73, Don W3FPR 2rGarry wrote: > Thank you Don. I think the most confusing part of all was, I was > looking for various width settings for the ssb filters. Eventually I > came to realize that I had to use the other filters for reduced > bandwidth for ssb. After that dawned on me it was relatively easy. > Or perhaps I still have not got it correct. Still can't get the > display on frequency. I guess I need a decent freq counter. Can't > seem to manage with wwv. > > cheerio and 73. > > Garry > > On Thu, Feb 11, 2010 at 8:52 PM, Don Wilhelm-4 [via Elecraft] > <[hidden email]> wrote: > >> Garry and all - at least those who are building new K2s. >> >> Yes, the filter setup is a bit "tricky", especially when using filter >> widths wider than 1.00 kHz. The reason is in the varactors that have >> shipped with the more recent K2 kits. What that means is that a filter >> width that is indicates as 2.00 kHz wide on the K2 may actually be 2.5 >> kHz wide (this is not exact, it all depends on the varactors). The >> result of this is that the LSB filter settings listed in the manual will >> be about right, but the USB settings will be way off. In other words, >> the manual settings will give you a workable filter for the lower >> sideband response, but will not work for the upper sideband (USB, RTTYr, >> and CWr) settings. (NOTE: the OP1 filter width is not affected by the >> varactors - there are no varactors on the KSB2 board). >> >> The only cure I know is to use Spectrogram or another audio spectrum >> analyzer to measure the actual width of the filter (in LSB or CW - not >> CWr - or RTTY - not RTTYr). When you use LSB, CW or RTTY, you should >> be on the lower sideband, and you can change the width without much >> movement of the lower end of the passband frequency. After getting the >> filer width as you like it, then refine the low frequency end of the >> lower sideband filter (by changing the BFO setting) and then set the USB >> BFOs to properly place the sideband. >> >> If you want specifics on how to set the filters, look at part 3 of the >> article on K2 Dial Calibration at my website www.w3fpr.com (while you >> are there, you may just want to go through the entire K2 Dial >> Calibration procedure which includes adusting the filters. >> I have not yet updated the webpage information to include how to handle >> this "varactor problem", but since you can see the passband width on the >> Spectrogram display, it should be obvious. Just adjust the width of the >> filter until the actual width is what you want, and use the K2 display >> only as a relative indicator. >> >> 73, >> Don W3FPR >> > 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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