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

[Don Wilhelm]

Dave,

Refer to the K1FL4 instructions and re-tune the trimmers on the filter 
board.  They MUST be done in the proper band sequence - 30 meters before 
40m, 15m before 20m.  The PreMixer portion is usually the most critical 
for power output.

73,
Don W3FPR

On 5/20/2020 11:20 AM, rocketnj at gmail.com wrote:
> 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%
>