Notes on Elecraft K3 (2)

50% of cost donated to CCC as a challenge grant. Bought and assembled by KB7Q in Bozeman. Click here for invoice.

Downloaded the K3 Utility at Station 2. KB7Q firmware was 5.01, ahead of the 4.86 currect release, so I did not change it.

K3 Configuration is saved at My Documents/...K3Config and at C:/Users/PJ2T/AppData/Roaming/Elecraft/K3 Configuration/...K3Config

Moved into Pelican case from Station 2 prior to WPX SSB 2015 contest. Working fine at that time.

N0YY installed at Station 5 in a rush before contest with no low pass filter in line. Front end was blown out by 20 meter backfeed. W8WTS hand carrying to Ohio 29 Nov 2016 in its Pelican case, then will forward to N7IR by Fed Ex. N7IR will repair and install synthesizer board (donation) and then ship to WTS who will bring it back to the island in late January.

I replaced the two damaged PIN diode pairs, D5 in the KXV3 and D25 on the RF Board, and K3 #8741 resumed regular operation. I checked all of the other parts in the RX path that could have been damaged and they are all good. As I think I mentioned to some of you, D5 caught fire! When I removed it the plastic package was mostly ash. I took photos to document the damage.

        

        Last week I installed the new KSYN3A synth board that I bought, and the 
        associated KPAIO3MDKT modification kit, along with the used KAT3 that 
        Gene donated.  Everything worked correctly on all bands except 20 
        meters, where the tuner could not find a match into a dummy load.  After 
        much thinking, testing and some correspondence with Elecraft K3 customer 
        support (which was minimally useful), I concluded that the 30/20 meter 
        band pass filter had not been aligned correctly when the RF board was 
        originally built and tested by Elecraft in 2014.  The attached jpeg 
        graph shows the frequency dependence of the transmit gain parameters 
        across the 20 meter band.  Since the automated TX gain calibration run 
        by the Elecraft K3 utility uses a single 20 meter frequency, 14200 kHz, 
        then the resulting power output in the CW portion of the band was not 
        enough to run the KAT3.  Yesterday I realigned the 30/20 meter band pass 
        filter and K3 SN 8714 is now running up to spec on all bands.

         

        I did one other modification that should be noted in the club 
        documents for this K3.  I drilled out the threads of the long hole on 
        the 2D fastener mounted on the upper right rear of the radio.  This 
        modification allows the right side panel to be removed and replaced 
        without removing any hardware from the KAT3.  I will send a copy of the 
        modification instruction sheet with the K3.

         

        I printed and attached a new label to the top of the radio indicating 
        the correct serial number and all of the options installed.

         

        Should I keep the old parts, the KANT and KSYN3 boards, that I 
        removed from this K3 or should I include them when I return it to Jim?  
        I will send the instruction sheets from the upgrades in any case.

         

        Jim, please let me know the address you want FedEx to ship it to.

         

        73

        Gary, N7IR

This will become the permanent Remote Station transceiver after N7IR swaps in the KIO3 USB board from K3(4) on site in November.