Noise floor testing

[CB590]

Using 38' 12THHN end fed with 9:1 unun (no counterpoise wire yet) fed with 40' of LMR-240 coax. Trying to lower noise floor for DX.

With no choke before transmitter and AGC at +10 which would be normal to hear DX stations:

160 . S8-9
80. S-9
60. S5-6
40. S4-5
20. S1-2
17. S4-5
15. S1.5
12. S1.5
10. S3.5

With MFJ 1:1 choke just before transmitter and inside shack room:

160 . S6.5
80. S-7.5
60. S3.5
40. S3
20. S0
17. S0
15. S0
12. S0
10. S0

No plans to use 160/80 as wire is way too short.

Not sure of db as I don't have reader for that.

Was suggested to check wwv for clarity and to see if signal is reduced or just noise to see if choke is choking signal or just noise.

Other tips??

 

[CB590]

Checked wwv as suggested. Got 10 MHz and 15 MHz signals from CO location pretty good at 11am They sounded 'cleaner' with the 1:1 inline..

Also on 14.290 with 0 S bars and 1:1 I could hear stations, once I removed the 1:1 the same stations were lost in the floor. I repeated several swaps and it just sounded better with the 1:1 in place.

 

[KD2GOE]

cool beans! i wish i had your luck i have a lot of "switch mode PSU" type noise around me i suspect it is an out door flood light as it shows up at night most of the time and when there is a lot of overcast. what ever it is i get s7~s9 on all the higher freq..

There is a few interesting videos on chokes on you tube on helping suppress common mode currents. and dropping the noise fore..

 

[CB590]

Well I installed the choke just outside shack wall (outside) as final install location about 8' away from transmitter. Had to add a counterpoise on the 9:1 unun to maintain 80m use.

Lost 60m TX, but OK with that.

Noise is less than S3 on 80m..so I'm happy.

 

[CB590]

Found right inductor setting to get 60m to tune up.

Did battery check with all normal circuits turned off.. No real change in RF noise audio levels. Guessing living in mobile home park does not help with other houses leas than 30-40' away..

40m was just noisy as heck today..