K2 Build - #6950
Locked
 
|
I received my kit on Wednesday and I got to the first alignment already! The front panel is done, the Control Board is pretty much done, and I started in on the RF deck. However, I am missing one of the caps for the Control Board #272 (.0027uH). Before I power up for the first time, am I OK with this stage the way it is or will that cap play a vital role? It is out of C36 (there are 3 of this value on the board). The schematic shows it goes between ground and the + side of U10B (an LMC660). You can follow my build progress on my blog at (mycall).com. (I tried sending the link and the reflector kicked it back - anything other than text gets "the boot") Steve, KC8QVO ______________________________________________________________ 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 |
|
|
Steve,
With C36 not installed, you may have a strange sounding sidetone note, but other than that things should work just fine. 73, Don W3FPR steve d wrote: > > > I received my kit on Wednesday and I got to the first alignment already! The front panel is done, the Control Board is pretty much done, and I started in on the RF deck. > > However, I am missing one of the caps for the Control Board #272 (.0027uH). > > Before I power up for the first time, am I OK with this stage the way it is or will that cap play a vital role? It is out of C36 (there are 3 of this value on the board). The schematic shows it goes between ground and the + side of U10B (an LMC660). > > You can follow my build progress on my blog at (mycall).com. (I tried sending the link and the reflector kicked it back - anything other than text gets "the boot") > > Steve, KC8QVO > > 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 |
|
|
I got the K2 powered up. It showed the default message INFO 201 and ELECrAFt, then 7100.00c. The display button won't switch anything and the VFO knob doesnt change the frequency (page 44, left column).
Time for some trouble shooting. Steve, KC8QVO |
|
|
Problem found. I did some swapnostics with a buddy's K2 and we traced the problem to the front panel. After going through all the resistance checks again my friend found the problem - U4 was backwards.
It took me quite a while to fix it. I used solder wick to suck out the solder. I am sure anyone that has done that on a 20 pin IC can relate - quite tedious to pull the chip without lifting a pad or pulling a plated thru hole! Steve, KC8QVO |
|
|
Steve, you are to be commended. Unsoldering a 20-pin IC?? Wow, you're good! My method is to just buy another IC and cut each pin from the old IC and remove the pins individually; I feel that is much less risky to do than trying to salvage the chip. But, good on you, Steve, for doing just that. Mark - W5EZY |
|
|
In reply to this post by Steve KC8QVO
Steve,
This is the reason I spent my money on the Hakko de-soldering gun. I was a test builder and found myself doing quite a number of mods. I also worked on some non - Elecraft boards of cheaper quality... and the de-soldering iron has save my butt. I have pulled a couple of traces in my past. Great you were able to do so with no damage. Bill K9YEQ K2 and KX1 field tester, K3 and modules -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Steve KC8QVO Sent: Wednesday, May 26, 2010 10:15 PM To: [hidden email] Subject: Re: [Elecraft] K2 Build - #6950 Problem found. I did some swapnostics with a buddy's K2 and we traced the problem to the front panel. After going through all the resistance checks again my friend found the problem - U4 was backwards. It took me quite a while to fix it. I used solder wick to suck out the solder. I am sure anyone that has done that on a 20 pin IC can relate - quite tedious to pull the chip without lifting a pad or pulling a plated thru hole! Steve, KC8QVO -- View this message in context: http://elecraft.365791.n2.nabble.com/K2-Build-6950-tp5091343p5106740.html Sent from the [K2] mailing list archive at Nabble.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 ______________________________________________________________ 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 |
|
|
Good news - the rig is on the air! I have made two QSO's on it so far. I tried holding off to get one of my friends to give me the first QSO but I scrolled past a guy calling CQ and just couldn't resist HI. So I have two QSO's on the rig so far.
I tuned the filters first with the receive method. I keyed up one of my other radios in to a dummy load and tuned the filters to peak the meter. I adjusted the power out of the radio so I got close to a jump in the meter on the K2. Then I fine-tuned the inductors and caps more. After the receive test it was on to the transmit. I peaked the filters for power out (based on the K2's internal metering while in "tune" mode). In most cases I was very close already. A couple of issues that need resolved - First - the buttons on the right side of the rig don't always work right. Specifically the filter button and the ATTN/PRE. They seem to have crossed signals with the display, band up, and band down functions. Any ideas on this one? Most notably - the filter button scrolls through the bands instead of adjusting the filter width. Second - I wasn't able to get any more than .6w out when I did the transmit test on 17m. It seems to me the caps were very touchy during the receive test. I was using a metal screwdriver to adjust them and that was playing all kinds of havoc on the tuning. So I went back to the tuning tool that came with it. The reason I wasn't using it before was because the caps were stiff and I didn't want to break the tool. Oh well - theres a reasn why the tool is plastic, eh? HI. In any event, I will get back over to my buddy's place with the test lab and peak the filters. 17m really seems goofy to me though. I was able to get nearly all the other bands cose on the receive tuning. Then when I hit 17m I couldn't get the power to go up for nothing. Hopefully this one is just being difficult and will be tuned in easier in a lab session. The buttons are also a bit of a concern. However, the transmitter and receiver work for the most part. Steve, KC8QVO |
|
|
Steve,
For your button problems, I would look on the front panel. Check RP1 to be certain it is installed the right-way-'round (this particular RPak cannot be swapped end for end like many others can). Also check the soldering at the switches as well as U2 and U3. If you want to follow along on the schematic, it would seem that there is a short between the /BANK1 and /BANK2 signals somewhere. Trimmers de-tuned by a metal screwdriver -- you installed the trimmer capacitors backwards. The flat is on the short end of the blue body trimmers - if you look closely, you will see that end is truely flat, and the wider end is rounded at the corners. It will cause no harm except that you must use a fully insulated tool for adjustment. 17 meter problem -- Make certain the inductors L10 and L11 are actually tuned for 15 meters. You may want to check the values and soldering of C30, C31, C33, C35 and C36. Once 15 meters is properly tuned, then 17 meters should adjust with the trimmer caps set near the center position (slots parallel with the front of the K2). 73, Don W3FPR Steve KC8QVO wrote: > Good news - the rig is on the air! I have made two QSO's on it so far. I > tried holding off to get one of my friends to give me the first QSO but I > scrolled past a guy calling CQ and just couldn't resist HI. So I have two > QSO's on the rig so far. > > I tuned the filters first with the receive method. I keyed up one of my > other radios in to a dummy load and tuned the filters to peak the meter. I > adjusted the power out of the radio so I got close to a jump in the meter on > the K2. Then I fine-tuned the inductors and caps more. > > After the receive test it was on to the transmit. I peaked the filters for > power out (based on the K2's internal metering while in "tune" mode). In > most cases I was very close already. > > A couple of issues that need resolved - > > First - the buttons on the right side of the rig don't always work right. > Specifically the filter button and the ATTN/PRE. They seem to have crossed > signals with the display, band up, and band down functions. Any ideas on > this one? Most notably - the filter button scrolls through the bands instead > of adjusting the filter width. > > Second - I wasn't able to get any more than .6w out when I did the transmit > test on 17m. It seems to me the caps were very touchy during the receive > test. I was using a metal screwdriver to adjust them and that was playing > all kinds of havoc on the tuning. So I went back to the tuning tool that > came with it. The reason I wasn't using it before was because the caps were > stiff and I didn't want to break the tool. Oh well - theres a reasn why the > tool is plastic, eh? HI. > > In any event, I will get back over to my buddy's place with the test lab and > peak the filters. 17m really seems goofy to me though. I was able to get > nearly all the other bands cose on the receive tuning. Then when I hit 17m I > couldn't get the power to go up for nothing. Hopefully this one is just > being difficult and will be tuned in easier in a lab session. The buttons > are also a bit of a concern. However, the transmitter and receiver work for > the most part. > > Steve, KC8QVO > 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 |
|
|
In reply to this post by Steve KC8QVO
Steve -
Great work. I have 6959 that I got a day or two later than you. I have finished the Part 1 test with no problem. This is my 3rd K2 (406 & 3638 done before). All I can add to what has been suggested is this > Check every component before you soldered it in. Sometimes I even turn the board around (front to rear) just to get a better perspective and ensure that I'm doing it correct. But since you have it finished you can't do that now. Also I ALWAYS inspect the board after finished with a magnifier to make sure all pads are soldered and not shorted or left open. I would suggest that you pull the front panel and reheat every connection. On the switches you can heat them on the front side and add some solder (the pins don't always go through the board). That way they will make contact through the plated through hole. Good luck finding the problem. John NQ3RP |
«
Return to [K2]
|
1 view|%1 views
| Free forum by Nabble | Edit this page |