[Elecraft] K2 transmitter alignment problems
Hello all, I have finally gotten to the final alignment portion of my K2 and have found power out problems on 3 bands, 80, 15, and 17 meters. The measurements follow: Band:2 watts setting 5 watts setting 10 watts setting 80 m. 2.0watts out1.8 watts out 1.8 watts out 20 m. 2.0 watts out 5.4 watts out 10.7 watts out 30 m. . 2.5 out 5.8 out10.6 out 20 m. 2.3 out 5.3 out10.6 out 15 m. 2.0 out 1.9 out 1.9 out 17 m. 2.0 out 3.9 out 4.0 out 10 m. 2.2 out 5.2 out 10.2 out 12 m. 2.0 out 5.2 out10.3 out All power at the 2 watt output setting was adjustable at the designated pots or capacitors. The rig had 13 vdc input and transmitting into a 50 ohm dummy load. Looking forward to suggestions. 73 Dan af4lb __ 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] K2 Transmitter Alignment problems
I've done all the construction up to the transmitter alignment on the base K2. I do not have a signal generator that puts out 0.14 volts. Bought the N-Gen and it doesn't provide a strong enough signal for signal tracing. So, how do I find my problems cure? Transmit on 40 meters, 30 meters & 20 meters works perfectly. i.e. I can align for 2 watts out. Transmit on all other bands will not show more than 0.2 watts out. I've re-soldered all joints in the LPF and BPF circuits. I've checked the values of all capacitors in those areas. Any ideas? Do I need a signal generator to signal trace? Ron, KE5QDA K2 6575 under construction ___ 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
[Elecraft] K2 Transmitter Alignment Problems
I have completed up to page 77 and can get one half of the bands to put out power. 80, 40, 17, and 15 meters will show power output on the internal watt meter. 30, 20, 12, and 10 meters will not show power output. Adjusting the variable inductors has no effect on wattage output. The PA transistors (Q7 and Q8) test good voltages. What appears faulty in the RF Board sheet of voltage measurements on page 17 are U4 pin 7 and U5 pin 1. These test 5 volts and are supposed to test 0 volts. Pins 7 and 1 are connected to each by looking at the pc board. Each of these pins is next to a pin on their IC containing 5 volts. Does this indicate that the problem may likely be a faulty IC? Q24 is testing about 75% of the specified at S & D pins while Q18 tests 0 at G instead of -1.0. I have removed low pass wound filter inductors for two nonfunctioning bands and reinstalled and this did not correct the problem on these bands. I would like to correct myself and not send away for repair. Your thoughts would be appreciated. Thank you, Dale, kc9cwb ___ 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 transmitter alignment problems
Dan, Did you find a peak on each of the bandpass filter tuning steps? If not, go back and align the bandpass filters. Set the power anywhere between 1.5 and 2 watts. Keep the power low (less than 5 watts) and you can find the peak more easily. When the power climbs (it will if the tuning was not 'right on'), exit tune and re-enter again to reduce the power. With the bandpass filters peaked for certain, check the power out at the 10 watt setting - if there is still a problem, go on to the next checks. You may have one too many turns on some of the LPF toroids - that would explain 80 meters and 17 meters, but not 15, so check the values of C118 thru C122 as well - on the toroids, count the number of times the wire passes through the center of the core. Check T4 - the "link" wires should go straight through the hole in the core, they do not go through both holes. Be certain Z1 and Z2 are in place and properly soldered. If all that is good and the problem persists, report back, but this time do the power out check only at 10 watts and also tap display and note the current draw. Depending on the results of that report, you may have to do some Transmit Signal Tracing, so build up the RF Probe from the parts provided with the K2 kit unless you have access to a 60+ MHz oscilloscope with a 10X probe of equal or greater frequency rating. 73, Don W3FPR Dan Grizzard wrote: > Hello all, > I have finally gotten to the final alignment portion of my K2 and have found > power out problems on 3 bands, 80, 15, and 17 meters. The measurements follow: > > Band:2 watts setting 5 watts setting 10 watts > setting > > 80 m. 2.0watts out1.8 watts out 1.8 watts > out > 20 m. 2.0 watts out 5.4 watts out 10.7 watts > out > 30 m. . 2.5 out 5.8 out > 10.6 out > 20 m. 2.3 out 5.3 out > 10.6 out > 15 m. 2.0 out 1.9 out > 1.9 out > 17 m. 2.0 out 3.9 out > 4.0 out > 10 m. 2.2 out 5.2 out > 10.2 out > 12 m. 2.0 out 5.2 out > 10.3 out > > All power at the 2 watt output setting was adjustable at the designated pots > or capacitors. > The rig had 13 vdc input and transmitting into a 50 ohm dummy load. > Looking forward to suggestions. > 73 > Dan > af4lb > __ > 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 > > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 9.0.791 / Virus Database: 271.1.1/2763 - Release Date: 03/22/10 > 03:33:00 > > __ 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 Transmitter Alignment problems
Ron, Does the receiver work on all bands? You can tell even if there are no signals available - turn the gain up to the point where you can hear a bit of noise with no antenna connected. Then connect an antenna - if the noise level increases, then the receiver is working. It may or may not be working well, but at least you can get a signal through it, and that is one giant step. If the receiver works on all bands, then you do not need a signal generator - the transmit stages serve to provide the RF signal, and yes, you do need to measure it. So you need an RF Probe. The parts required to construct an RF Probe were included with your K2 kit. Backing up a bit - if the receiver does not work, yes you will need a signal generator of some sort to make troubleshooting easier. But first try the K1 and K2 Cheap and Dirty Signal Tracing technique. Look on the Elecraft website Builder's Resource page. 73, Don W3FPR Ron McCurdy wrote: I’ve done all the construction up to the transmitter alignment on the base K2. I do not have a signal generator that puts out 0.14 volts. Bought the N-Gen and it doesn’t provide a strong enough signal for signal tracing. So, how do I find my problems cure? Transmit on 40 meters, 30 meters & 20 meters works perfectly. i.e. I can align for 2 watts out. Transmit on all other bands will not show more than 0.2 watts out. I’ve re-soldered all joints in the LPF and BPF circuits. I’ve checked the values of all capacitors in those areas. Any ideas? Do I need a signal generator to signal trace? Ron, KE5QDA K2 6575 under construction ___ 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
