[Elecraft] K1-4 low power and poor receive on 40 meters

[rocketnj at gmail.com]

Hi All,

 

I am going to sell a K1-4 (4 band 40, 30, 20, 15) for the estate of my
Elmer. In testing the radio I found 40 meters is about 15dB less sensitivity
than 30 and power out about 75 mW. I have double checked the values of
components on the filter board to ensure they are correct and installed
correctly. I also checked T3 and T4 which can cause issues on 40. T3 has 23
turns on the secondary with three turns on the primary. T4 has 24 turns on
secondary and two turns on primary. Another symptom is the CH trimmer cap
seems to be at one end of tuning range (not seeing double peak).

 

Note - the radio does not have the ATU option and 30 meters is set for 10.1
MHz and not 10.0 (double checked crystals).

 

>From what I can measure so far the relays seem to be working "as designed".
When I switch from 15 meters to 40 meters I can see the pulses to the relays
to switch them (latching relays. I did notice in the 4 band filter manual it
says K6 relay is not active on 40 but I do see it active and looking at the
schematic K6 switches between 15/20 operation and 30/40 so I think there is
a typo in the filter board manual at the bottom of page 23.

 

I am using a Marconi service monitor for testing. I have not built an RF
probe yet and hoping someone has seen this symptom before. I would like to
get the K1 fully operational as the proceeds are going to my Elmer's widow
100%

 

Thanks for reading!

 

Dave wo2x