Hi Gang,
This is my first post to the group and I am hoping you can help me. After completing my K2 (s/n 5581) a couple months ago I was asked to look at another local ham's K2 (s/n 600). All I was told was that it didn't have any output and gave the Hi Cur warning with anything above 0.1 Watts. The radio itself is in good shape and only has the Noise Blanker option installed. After some initial test I have found that there is output, but the Hi Cur warning is still a problem. Using my multimeter set to read current I found the a power setting of 0.2 Watts or higher will draw 2.4 Amps of current or more with the output connected to a dummy load. I am guessing this may be a problem in the PA, but would like some input on where to start looking. Any help would be greatly appreciated. 73, Kevin KG4TEI _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
Kevin,
The most common reason for Hi-Cur along with low power output is something wrong between the PA transistor collectors and the antenna. First be certain that the K2 is operating into a good 50 ohm dummy load. If the results you posted are into an antenna, the antenna feedpoint impedance may be at fault. Secondly, check the Low Pass Filters for correct capacitor values, correct number of turns on the toroids, and good soldering - especially the toroid leads. Poorly tinned toroid leads is a common problem. If all the above checks out, look carefully at T4. It should be wound as indicated in the manual and the leads should be in the correct places. If the problem occurs on only a few bands, the problem will be found in the LPF area, but if it is present on all bands, look at T4 more carefully. The other thing to check is the bias to the PA transistors. The voltage at the PA bases during transmit should be very close to 0.6 volts. If it is anything other than that, look at the biasing components. 73, Don W3FPR > -----Original Message----- > > Hi Gang, > > This is my first post to the group and I am hoping you can help me. > After completing my K2 (s/n 5581) a couple months ago I was asked to > look at another local ham's K2 (s/n 600). All I was told was that it > didn't have any output and gave the Hi Cur warning with anything above > 0.1 Watts. The radio itself is in good shape and only has the Noise > Blanker option installed. After some initial test I have found that > there is output, but the Hi Cur warning is still a problem. Using my > multimeter set to read current I found the a power setting of 0.2 > Watts or higher will draw 2.4 Amps of current or more with the output > connected to a dummy load. I am guessing this may be a problem in the > PA, but would like some input on where to start looking. Any help > would be greatly appreciated. > > 73, > Kevin > KG4TEI > _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
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