[CQ-Contest] 15m RFI hurts rate and score

[Mike & Coreen Smith VE9AA]

When 10 is dead, my go-to band is 15m
.(who’s isn’t?)

 

Having 15m RFI is a PITB.

 

All RFI stories welcome. I guess I have been lucky the past few decades as I
have rarely had RFI, even when QRO. I have not had a stn ground (until
today) here at this QTH (been here 10yrs now)

-------------------------

I won't claim that my RFI is cured, but it is at least somewhat diminished.
It's been really peeing me off lately when running HP on 15m I get RF into
the audio and more often than not, the logging program loses rig control
and/or control of my Winkeyer USB (CW keyer) requiring a reboot. Sure cramps
my style on 15m. I (primarily) run a Butternut HF9V all band vertical
(raised up around 8') with raised radials , IC7410 and a MLA2500 which gives
me about 600w on 15m CW.

 

What I did over the w/e and today was add 2 galvanized 1½" diameter ground
pipes (not rods).....the soil here is rock, so I could only get down about
3½ feet, so I used 2 pipes and fed about 20' of #6 AWG copper up into the
shack and tied rigs & stuff together, incl. the case of the Winkeyer USB
keyer box ...My shack is on the 2nd floor....thinking of adding 1 or 2 more
pipes.....worth it?

 

I only noticed today that when I unplugged the footswitch from my IC7410 my
15m SSB RF feedback in the audio completely went away, so I replaced the
wimpy audio cable to the foot pedal with RG-174/u coax and added a bunch
more ferrites to it.

 

I moved the Winkeyer USB physically away from the mic and foot switch lines
and added another ferrite, thinking perhaps the footswitch line is possibly
acting as an antenna reradiating RF.

 

I also added yet another "air" core 5t on a 7" plastic form, coaxial balun,
(impedance peak presumably around 21MHz) at ground level where the coax
enters the house. ( I also have an air core balun near the base of the
antenna, some 75' away which is about 12t on a 7" 'air' form.

 

All these factors combined have surely reduced the 15m RFI.

 

I can make that statement with some assurance, as I have a small LED on my
HF9V switchbox that sits on my desk (it's a mod--check the Butternut Yahoo
group) which used to blink nicely with my CW.....it no longer does. I kinda
miss it, but the 15m SSB RFI is totally gone.

 

The Winkeyer USB (CW) box used to lock up the radio into keydown mode (along
with losing rig control by N1MM sometimes) but usually only on 15m
CW....time will tell if I have cured that !

 

Fingers crossed.--Mike VE9AA

p.s.- I also have some crud getting into my RX only on 15m, but I don't
think it's in the house. I have shut every breaker off except the one for
the rig and it continues. Perhaps a neighbour, but I did not yet rule out my
switching power supply......

 

 

 

Mike, Coreen & Corey

Keswick Ridge, NB