Re: [Elecraft] [K2] No signal at TP1 during Alignment and Test Part 2
Well it was T5! Sorry to take so long to get back but free time has been short lately. Lead 4 of the transformer was poorly stripped as expected. I also think I need to run a little more heat when I'm soldering from this point forward to make sure i get good connections made. Thank you to everyone who responded. After I finish my happy dance I think I'll go make a cocktail! 73, Robert AD0TA On Fri, Jun 9, 2017 at 8:48 AM, Ron Manfredi <wa2...@optonline.net> wrote: > I agree with Don's comments on the soldering. > > I am not familiar with the kit, but if you had to wind the torroid > yourself, were you sure to remove ALL the insulation from the wire ends > before soldering them to the board? > > > 73, > > Ron WA2EIO > > > > > On 6/9/2017 10:41 AM, Don Wilhelm wrote: > >> Robert, >> >> I just now had time to look at your photos. It seems to me that your >> solder on T5 (and maybe elsewhere) looks like "balls" with convex sides. >> That is indicitive of a solder connection that has not received enough heat. >> A good solder connection should have a slight fillet and end up with >> obvious solder that has flowed out entirely onto the solder pad and also up >> onto the leads. The edges of the solder should taper out to an almost >> invisible edge with a concave fillet of solder between the pad and the lead. >> See the diagrams in the Soldering Tutorial available at the Elecraft >> website (you may have to search for it). >> >> I suggest you remove the solder from any connection that looks like those >> and re-do them. Do not apply so much solder to "pile it on" - that does no >> good. Heat the solder pad and lead until you can see the solder flow out >> onto both. >> >> Using a small gauge solder helps. With large diameter solder, by the >> time you apply 'a little bit', that is already too much. Save the large >> solder for antenna wires. >> >> 73, >> Don W3FPR >> >> On 6/8/2017 10:20 PM, Robert Forster wrote: >> >>> >>> This should lead me to suspect T5 correct? >>> the soldering on the underside of the board for T5 looks ok (no ring for >>> these points but the topside of the board looks rough! I used the USB >>> microscope and took some photos. >>> Here: https://flic.kr/s/aHsm2aNdeG >>> >>> >>> >> __ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to wa2...@optonline.net >> >> > -- === I could tell you a UDP joke, but you might not get it. === __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] [K2] No signal at TP1 during Alignment and Test Part 2
Hi Don and Group, I got a bit of time to troubleshoot this evening. I do have a good signal at TP3 so I am ignoring the PLL and U4. I did the DC measurements at Q18 and found some issues. the gate shows as a negative polarity but at -.001 volts Source is .08 Drain is at 6.8 This should lead me to suspect T5 correct? the soldering on the underside of the board for T5 looks ok (no ring for these points but the topside of the board looks rough! I used the USB microscope and took some photos. Here: https://flic.kr/s/aHsm2aNdeG I'm thinking that after the VHF contest I should remove T5 and check the windings and re strip the ends and retin. Does this sound like an apropriate course of action? Oh and just for the hell of it I bypassed C60 with no effect either. Thanks again for all your help! 73, Robert AD0TA On Wed, Jun 7, 2017 at 6:33 AM, Don Wilhelm <donw...@embarqmail.com> wrote: > Robert, > > Do you have a good signal at TP3? If so, ignore the PLL Reference > oscillator and U4 for now. > > You need to get the VFO operating before doing anything else. > Do the DC measurements a Q18. If you do not have a negative voltage at > the gate, it is not oscillating. > > T5 is the most likely problem with the VFO. Make certain it is wound > correctly and the leads are well stripped and tinned. If you see a ring > around the lead (on the solder side), that lead was not adequately stripped > and tinned. Both windings must be wound in the same direction. > > If all the above is correct, put a temporary jumper across C60 to disable > the VFO ALC circuit. If it oscillates with the jumper in place, but not > without it, replace Q17. If that still does not correct it, try replacing > Q16. Be certain D11 is oriented correctly. > > Ignore the voltages on U4 pins 5, 6, and 7 - those are digital signals, > and the manual lists the voltage for the active signal, not what you would > typically measure with a DMM. If you look at them with a 'scope you can > see pulses on those lines, and that should be sufficient for proper > operation. > > RFC 15 also needs to be ignored until after you get the VFO operating. > Once you get a VFO signal at TP1, then you can investigate the operation of > U4. > > 73, > Don W3FPR > > > On 6/6/2017 9:47 PM, Robert Forster wrote: > >> Hello to the group! >> >> I'm afraid I need to lean on your collective K2 troubleshooting expertise. >> After a long break I have finally made it to the Alignment and Test Part 2 >> of my build. Everything was going OK until I got to the VCO Test. I have >> no signal at TP1. I have tested this with the built in counter as well as >> an external counter. I have gone through some of the troubleshooting I >> could find online: >> >> The orientation of D13 and D8 look good >> >> I have checked the soldering at relays K13, K14 and K15 and the value of >> C72. >> >> I have checked the varactors at D21 through D26 and they are oriented >> properly I am nearly certain they are all the correct type >> >> I tested RFC15 in the circuit and could not get any continuity through it. >> When I pulled it out of the circuit it tested fine so I put it back in. >> I'm sure this is something basic I just dont understand. >> >> I know there is some more testing I can do with Q17 and Q18 (I did check >> that they are the right type and orientation I also check all the >> component >> values around Q18) Lets set that aside for just a second though... >> >> Here is where I think it gets a little weird. Looking at the schematic I >> followed it back to U4. When I compared the voltage table to what i was >> actually seeing on U4 I think I may have found my problem. According to >> the table pin 7 should have 0 Volts but i'm showing 4.8! It also shows >> that pin 13 should have 4 volts but I'm showing 0. All other pins are >> normal and match the chart. >> >> Following Pin 7 of U4 back to Pin 1 of U5 I see the same 4.8 volts. >> This is supposed to be a clock line so I'm confused where this sort of >> voltage would be comming from. >> >> I'm still new to alot of this and this is by far the most complex kit I've >> taken on so any and all help will be appreciated! >> >> Thanks and 73, >> Robert >> AD0TA >> >> >> >> -- === I could tell you a UDP joke, but you might not get it. === __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] [K2] No signal at TP1 during Alignment and Test Part 2
Hello to the group! I'm afraid I need to lean on your collective K2 troubleshooting expertise. After a long break I have finally made it to the Alignment and Test Part 2 of my build. Everything was going OK until I got to the VCO Test. I have no signal at TP1. I have tested this with the built in counter as well as an external counter. I have gone through some of the troubleshooting I could find online: The orientation of D13 and D8 look good I have checked the soldering at relays K13, K14 and K15 and the value of C72. I have checked the varactors at D21 through D26 and they are oriented properly I am nearly certain they are all the correct type I tested RFC15 in the circuit and could not get any continuity through it. When I pulled it out of the circuit it tested fine so I put it back in. I'm sure this is something basic I just dont understand. I know there is some more testing I can do with Q17 and Q18 (I did check that they are the right type and orientation I also check all the component values around Q18) Lets set that aside for just a second though... Here is where I think it gets a little weird. Looking at the schematic I followed it back to U4. When I compared the voltage table to what i was actually seeing on U4 I think I may have found my problem. According to the table pin 7 should have 0 Volts but i'm showing 4.8! It also shows that pin 13 should have 4 volts but I'm showing 0. All other pins are normal and match the chart. Following Pin 7 of U4 back to Pin 1 of U5 I see the same 4.8 volts. This is supposed to be a clock line so I'm confused where this sort of voltage would be comming from. I'm still new to alot of this and this is by far the most complex kit I've taken on so any and all help will be appreciated! Thanks and 73, Robert AD0TA -- === I could tell you a UDP joke, but you might not get it. === __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] K2 No LCD display
Hello all, I finally made it to the first power up of my K2 and seem to have hit a snag. The radio powers up, The relays click and the backlight of the LCD comes on but no text. After searching the list it seems that pin 1 of the driver is a likely suspect. I took a look at it with a USB microscope and it looks like the solder joint there is fine. I posted a picture of it here: https://flic.kr/p/P3Esg4 Here are the steps I've taken so far: I reflowed a few of the pins that looked suspect going from the LCD to the driver IC Checked the values of R15 and 16 they both test as the correct values I show fluctuating voltage on pins 16 and 17 indicating data is present Pulled the Driver IC and tested continuity from pins 1 and 2 to the rf board connector pins 16 and 17 Further tested continuity from lcd controller pins 1 and 2 all the way back to pins 38 and 39 on the MCU Confirmed proper voltage to the MCU (5V) and I do hear the oscillator @ 4Mhz Confirmed I am getting 5v at the voltage regulator on the control board and that is making it to the front panel board I'm not sure what else to test now. One thing that is mentioned in the troubleshooting is if the bargraph is also not working to check the 5V line. Should the bargraph be lit at all during power up? Maybe that's a clue? I would like make sure I'm getting the 2V? to the LCD driver but when everything is assembled I cant get at that pin. Thanks for any and all help! Robert AD0TA -- === I could tell you a UDP joke, but you might not get it. === __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Looking For Rework Eliminator Option Bypass Headers
I found a set. Thank you to everyone who responded. Looking forward to sharing my trials and tribulations with the list as I start my largest kit build to date! 73, Robert AD0TA On Thu, Sep 22, 2016 at 10:00 AM, Robert Forster <robert.fors...@gmail.com> wrote: > Hello all, > > First time poster to the group. > I've been looking at building a K2 to use as an IF rig and I'm really > close to pulling the trigger. I'd like to build this rig with the > bypass headers from unpcbs.com but it seems they are sold out and not > anticipating another run. I'd like to build this rig so it is as > flexible as possible so if anyone has a spare set they would like to > sell please contact me off list. > > Thanks and 73, > Robert > AD0TA > > > > > > -- > === > I could tell you a UDP joke, but you might not get it. > === -- === I could tell you a UDP joke, but you might not get it. === __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] Looking For Rework Eliminator Option Bypass Headers
Hello all, First time poster to the group. I've been looking at building a K2 to use as an IF rig and I'm really close to pulling the trigger. I'd like to build this rig with the bypass headers from unpcbs.com but it seems they are sold out and not anticipating another run. I'd like to build this rig so it is as flexible as possible so if anyone has a spare set they would like to sell please contact me off list. Thanks and 73, Robert AD0TA -- === I could tell you a UDP joke, but you might not get it. === __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
