[Elecraft] K£ - Multiple faults

[Tom Boucher]

I'm posting some detail of this long saga of faults on my K3 and the eventual solution, in the hope that it may help others with similar problems.

My K3/100 S/No 01434 is just about 3 years old now and about a year ago intermittently started showing faults. At switch-on 'ERR BP1', 'ERR LPF' and a long string of error messages would be displayed as the MENU button was pushed. It would then return to normal operation except power output was limited to 12 watts.

After a month or two, additional faults began to occur, 'HI RFI' displayed with no antenna connected and before transmitting. Internal relay clicking in time with keying, even when no separate receive antenna connected. High SWR indication on K3 bar-graph even with 50 ohm dummy load and perfect SWR on external meter. Transmit function inhibited. Uncalled for output power reduction from 100 W to 10 W during transmission. 'ERR PL2'  (PLL1 *00, PLL2 *00) and neither Rx working. 'ERR KEY'. Power on/off button not working. Tx gain calibration showing gain errors and slow to reach 10 W and 100W. 'HI TEMP' displayed at switch-on and before transmitting. 'ERR I01' and no RF output when keyed.

All these faults occurred regularly at different times over the last 12 months, interspersed with periods of no faults. The rig became quite unreliable, failing in the middle of a contest several times, and finally becoming virtually unusable.

During this time I dis-assembled the rig, removing all the sub-modules from the main RF board, cleaned the connectors and re-assembled, 3 or 4 times. The fault appeared to be temperature dependant so I used a freezer aerosol on each section of each board without being able to replicate the faults. Putting the whole rig in the 'fridge at -1C caused the faults to re-appear (had to move the beer to make room for it). All calibration procedures were repeated as per the handbook.

A month ago, John G3PQA kindly loaned me his K3 front panel along with some connector lubricant called Contralube 770. This was installed and the rig used for 2 or 3 weeks with no repetition of the faults even at low temperatures. My front panel has now been re-installed, using the connector lubricant on the 4 connectors and for about 2 weeks there has been no repetition of the problems.

My shack is in an insulated room in a stable block and the temperature does get below zero at times and I guess the humidity must get high as well. The 4 front panel connectors on my K3 are not gold flashed like some of the other modules and I can only assume that I had a connector pin oxidisation problem. So if anyone else has a series of faults like this, remove the front panel, clean the connectors and apply some of this special connector lubricant. An added advantage is that the front panel can now be removed using just finger and thumb, no screwdriver needed as a lever.

I have to say that throughout this saga, Elecraft post-warranty support has been superb, suuplying replacement modules and plenty of advice  from Gary Surrency. Wayne even wrote some special FW with extra timing delays built in to try and resolve the issues. Despite all this, I remain convinced that the K3 is the best transceiver on the market.

73
Tom G3OLB