HF noise.
Hi the hf noise is around s8 across all bands so i decided to try and improve this
I looked at possible causes and i noted if i ran a 6 mtr lead directly to the elevated multiband vertical AE and a battery sdr radio the noise was a lot lower around s4 i concluded from this it had to be either coming in from the mains or the coax. 1 i ran a new length of rg213 no change, 2 constructed a comprehensive mains filter both common mode and diff mode no change 3 put common mode filters at both ends of the coax one close to AE the other close to the rig now qrm at s4 across the 80 to 10 mtr bands, the noise had to be picked up on the outer of the coax this was earthed. i had no rf in the shack and the match was good 1.1/1 the clue now thinking about it if i changed the length of the patch lead the swr would change, now no different what ever the length . Mick
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