Re: [Elecraft] K2 Control board resistance checks
David, Welcome to the world of Elecraft. Do stay around - no harm done. If you are using Nabble to respond, know that those of us on the official Elecraft reflector see only what you wrote and none of what you are referring to - unless you copy a bit of it in your post. Nabble is not maintained by Elecraft - it is a secondary service. The Elecraft list is not threaded, and it comes in as sequential emails. My email client can show the posts as threaded if I want, but then I don't keep all emails on my computer, and I prefer not to use the threaded view. With a bit of reminder text, most posts make sense for me - but with no reminders, they often have little meaning. It does sound like you got through the resistance checks OK. Enjoy the rest of the K2 build. 73, Don W3FPR On 7/14/2014 12:17 AM, David_3 wrote: Sorry Don, I'm new to the the Reflector, and didn't mean to create a problem. I figured since I was replying to a particular thread, it would all make sense. I guess I was wrong. So hopefully, here is some reference material. If I screw it up this time, just ignore everything, and I'll go away entirely. Dave __ 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 Control board resistance checks
Wow, I'm glad I found this post. I just completed building the control board for my K2, and found the resistance on U6 pins 29 and 30 to be 96.4K. I didn't really think it was an issue, but it is always nice to have someone else confirm it. All other resistance checks were within specs. Thanks. -- View this message in context: http://elecraft.365791.n2.nabble.com/K2-Control-board-resistance-checks-tp4405430p7591157.html Sent from the Elecraft 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: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 Control board resistance checks
What post? Your post makes no sense without a bit of reference material. Sorry, but I subscribe to the Elecraft reflector and do not have time for threaded conversations that might appear on nabble. Please copy a bit of your referenced text in the future. 73, Don W3FPR On 7/13/2014 10:46 PM, David_3 wrote: Wow, I'm glad I found this post. I just completed building the control board for my K2, and found the resistance on U6 pins 29 and 30 to be 96.4K. I didn't really think it was an issue, but it is always nice to have someone else confirm it. All other resistance checks were within specs. __ 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 Control board resistance checks
Sorry Don, I'm new to the the Reflector, and didn't mean to create a problem. I figured since I was replying to a particular thread, it would all make sense. I guess I was wrong. So hopefully, here is some reference material. If I screw it up this time, just ignore everything, and I'll go away entirely. Dave Paul, Yes, those are OK. They are the DOT and DASH lines to the microprocessor and have nothing else but U6 on the Control Board to bring the resistance down. In general, a 10% deviation from the values listed in the manual are close enough. 73, Don W3FPR Paul Huff wrote: Hi everybody, I recently started building a K2 and I've just finished the assembly of the control board. My resistance checks are all within specs except two of them are just a little bit off. My readings at pins 29 and 30 of U6 are a little bit higher than those listed in the table. (I'm getting about 96.3 K and the table lists 70-90 K.) I think that these readings are probably OK, but I thought that I would ask someone who has been there and done that. Is there any need to be concerned about these checks? Thanks in advance and 73, Paul - N8XMS Don Wilhelm-4 wrote What post? Your post makes no sense without a bit of reference material. Sorry, but I subscribe to the Elecraft reflector and do not have time for threaded conversations that might appear on nabble. Please copy a bit of your referenced text in the future. 73, Don W3FPR On 7/13/2014 10:46 PM, David_3 wrote: Wow, I'm glad I found this post. I just completed building the control board for my K2, and found the resistance on U6 pins 29 and 30 to be 96.4K. I didn't really think it was an issue, but it is always nice to have someone else confirm it. All other resistance checks were within specs. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto: Elecraft@.qth This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to lists+1215531472858-365791@.nabble -- View this message in context: http://elecraft.365791.n2.nabble.com/K2-Control-board-resistance-checks-tp4405430p7591160.html Sent from the Elecraft 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: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 Control Board resistance checks
Ed, The first two readings are very likely OK, you might re-check by reversing the leads or putting new batteries in your DMM. The other possibility is that you are using auto-ranging, and the reading may be a bit different if you switch to the first fixed range greater than 90k I don't know how you DMM indicates an infinite reading, but you can easily check - it will be the same reading as you get with nothing connected to the leads. 73 Don W3FPR On 2/12/2011 1:19 PM, EMD wrote: I have some questions on the results of my check. U6 pin 29 should read between 70 and 90k, I'm reading 96k. U6 pin 30 should read between 70 and 90k, I'm reading 97k. U8 pin 15 and 16 should read100k, I'm not getting a reading at all so I'm wondering if this is the way my DMM reads infinity. Are these readings in the ball park or do I have some trouble some where? 73, Ed KE7HGA __ 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
Re: [Elecraft] K2 Control Board resistance checks
Those should be good, Ed. When trying to measure resistance in a circuit containing semiconductor junctions, DMMs voltage can sometimes alter readings a bit. You are within 10%. Many DMMs give no reading at all when seeing an open circuit. What does you DMM do in resistance scale with the leads not touching anything? Ron AC7AC -Original Message- I have some questions on the results of my check. U6 pin 29 should read between 70 and 90k, I'm reading 96k. U6 pin 30 should read between 70 and 90k, I'm reading 97k. U8 pin 15 and 16 should read 100k, I'm not getting a reading at all so I'm wondering if this is the way my DMM reads infinity. Are these readings in the ball park or do I have some trouble some where? 73, Ed KE7HGA -- __ 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
Re: [Elecraft] K2 Control Board Resistance Checks
Paul, Yes, you would connect one lead (usually the black one) of your DMM to ground. If by no reading you mean infinite resistance (the same thing the meter displays when the leads are not touching anything), then those two readings are correct. The other problem I see is the measurements at U6 pins 29 and pin 30. Are you certain you are counting the pins correctly. The pin numbering on an IC proceeds around the chip in a counterclockwise manner (looking from the top) - on U6, pin 21 is directly across the chip from pin 20. If you counted the pins 21 -40 backwards, you would end up at pins 32 instead of 29 - which is the 5A voltage rail and your measurement looks suspiciously like the reading you got at the 5 volt side of the 5 volt regulator. Also you would have mistaken pin 31 for pin 30 and pin 31 is ground which should properly give a 0.00 kohm reading. 73, Don W3FPR On 12/5/2010 2:18 PM, Paul Agoglia wrote: I have just finished the assembly of the K2 Control Board and am doing resistance checks, as per assembly instructions. Since I have not done something like this before I am hoping I have interpreted the directions correctly. The directions say to take measurements with respect to ground. I am taking that to mean that after I set my multimeter to an appropriate ohms range, that I touch one test lead to the pin to be tested, and the other test lead to a place on the circuit board that is labeled 'ground'. Can someone tell me if my interpretation of the directions is correct, and if so, then I have the following readings. I have highlighted in red the readings that do not fall within the expected outcomes. Any insights would be helpful! I am using a Radio Shack DMM. Pin TestedShould ReadWhat I got P2 P110k slowly moves to 360k -400k U5 5V pin2k13.96k U4 8V pin3-7k3.58k Q1 Collector1MOhm no reading Q2 Collector1MOhm no reading U3 Pin 810k193k U6 Pin 13100k316k U6 Pin 14100k326k U6 Pin 2970-90k13.97k U6 Pin 3070-90k0.0 ohms U8 Pin2100k257k U8 Pin 15100k245k U8 Pin 16100k251k __ 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
Re: [Elecraft] K2 Control Board Resistance Checks
Hi Paul WN2K, What I propose you do is: 1) Set the return/ground/neutral lead - typically the black lead - of your multimeter, to one of the grounding terminals that you soldered into the control board using a piece of component lead. The easiest way for you to do this is to use an alligator clip, preferably if your multimeter already is supplied with this. 2) You may wish to start with self-testing the ohm meter by itself: Short the two test leads and read out something around 0 ohms. Take a couple of resistors from your junk box, say 1k, 10k, 100k, 1M and measure each of them with the appropriate range. You should see your ohmmeter respond accordingly. Purpose of this test is to build up your own confidence to your test instrument measuring correctly, before you start measureing on your assembled control board and suspect this being wrong. 3) For each of the measurements you need to perform according to the checklist, you set the Ohmmeter's range on the closest level ABOVE this range. Say you need to measure U3 pin 8 to 10k ohms, and your ohmmeter has a 20k range, you set it to 20k. Then you probably in this case see the meter indicate open, so you change to the next range - e.g. 200k ohms and try again. Then if still no reading, change to 2M ohms and try again, until you get a proper reading. Write down this reading in(or by) the right column of the checklist in the assembly manual, in case you need to come back later and debug any further. 4) For some of the system you may see a slow change over time, but this should not be orders of magnitude and should NOT approach the limit listed in the checklist, so I suspect your reading on P2 P1 is ok in this case. 73' Brian OZ2BRN K2 # 6936 Den 05-12-2010 20:18, Paul Agoglia skrev: I have just finished the assembly of the K2 Control Board and am doing resistance checks, as per assembly instructions. Since I have not done something like this before I am hoping I have interpreted the directions correctly. The directions say to take measurements with respect to ground. I am taking that to mean that after I set my multimeter to an appropriate ohms range, that I touch one test lead to the pin to be tested, and the other test lead to a place on the circuit board that is labeled 'ground'. Can someone tell me if my interpretation of the directions is correct, and if so, then I have the following readings. I have highlighted in red the readings that do not fall within the expected outcomes. Any insights would be helpful! I am using a Radio Shack DMM. Pin TestedShould ReadWhat I got P2 P110k slowly moves to 360k -400k U5 5V pin2k13.96k U4 8V pin3-7k3.58k Q1 Collector1MOhm no reading Q2 Collector1MOhm no reading U3 Pin 810k193k U6 Pin 13100k316k U6 Pin 14100k326k U6 Pin 2970-90k13.97k U6 Pin 3070-90k0.0 ohms U8 Pin2100k257k U8 Pin 15100k245k U8 Pin 16100k251k Thanks, 73 de WN2K Paul Agoglia __ 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 __ 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
Re: [Elecraft] K2 Control board resistance checks
Paul, Yes, those are OK. They are the DOT and DASH lines to the microprocessor and have nothing else but U6 on the Control Board to bring the resistance down. In general, a 10% deviation from the values listed in the manual are close enough. 73, Don W3FPR Paul Huff wrote: Hi everybody, I recently started building a K2 and I've just finished the assembly of the control board. My resistance checks are all within specs except two of them are just a little bit off. My readings at pins 29 and 30 of U6 are a little bit higher than those listed in the table. (I'm getting about 96.3 K and the table lists 70-90 K.) I think that these readings are probably OK, but I thought that I would ask someone who has been there and done that. Is there any need to be concerned about these checks? Thanks in advance and 73, Paul - N8XMS __ 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
RE: [Elecraft] K2 control Board Resistance Checks
If you get strange readings after reversing the leads try reading the resistance on pin 21 (8R) and pin 23 (8T) of P2 Look at Appendix B Control Board. even the best of us occasionally mistake the pin out on transistors. Rich, KE0X Chuck, Try reversing your DMM probes - it is possible that no real problem exists. ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
Re: [Elecraft] K2 Control Board Resistance Checks
Jeff, The reading is a wee bit on the low side, BUT... The proper answer depends on your DMM. First try reversing the probes, and try another DMM if you can obtain one (beg or borrow). Bottom line - know your test instruments and their limitations - only then can you know whether a problem exists or not. 73, Don W3FPR - Original Message - I have just completed the Control board on #3375 and have a question about the resistance checks. Specifically the check on U4, OUT The manual says to look for 3-7 k at this pin ... and I measure 2.48 k with my DMM. Is this value close enough? Should I be looking for a problem to correct? ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
