2003 Passat condenser AC motor filter

[n3chu]

Hi all, I have a 2003 passat wagen with a Syntor-x lowband operating on 6 meters and 10 meters. I have been fighting this RFI problem for ten years that is comming from the AC condenser fan motor which I think is AC not DC, tried all combanations of caps, ferrite filters(snap on) and even put a new "twisted #10 power cord on it to the controller and it didnt touch the noise. the extender is tuned closer to the 6 Meters than ten. Even tried a new motor and nothing has worked?.. what am I missing? I have have fixed the alternator noise and thats no longer a problem. Does anyone make a plug and play filter that could be inserted into the power cord.? any help would be greatly appreciated .. Thank you. Davie n-3-c-h-u-at atlanticbb dot net P.S. every DC line going into the head and main radio is very filter

[HLA]

there is a resistor pack that controls that fan, you checked into that?

[n3chu]

Havent seen a resistor pack but the fan does have a fan controller box. was looking at websites that carry fan etc. and did see a resistor pack for some older VWs. the fan is actually radiating the noise as when I disconect the antenna it goes away.

[Will]

Davie,

The fan controller is probably a PWM and that can produce noise from the sharp edge switching wave form. Kinda like a switching power supply. The trick is round off the square waves.

I am thinking a big capacitor, 2000-10000 uF to ground on the input to the fan controller. Maybe even a choke in the pos DC before the fan controller.

[n3chu]

Thanks Will, I had thought of that but have had the fan removed each time I tried to mod it(four times) and may have worn out my welcome at the audo electric place. the car sits low to the ground tho I know what the controller looks like , I cant get to it at preasent. I'm going to get my oil changed soon and maybe they will let me get under it while it s on the lift to get an idea how to mount the cap. thank you for your reply as always. Davie

[n3chu]

Will, I did as you suggested and used an 8000mf and it took out the noise, I cant find it anywhere BUT now the air conditioner fan cuts on and off??. Maybe a smaller value cap??I did put a .001 acrossed the big cap also, seems that I remember somthing about thaat covering the high freq noise.Davie

[n3chu]

Guess I was overcome with happiness at the fact that I had been trying to get rid of that noise for ten years that I think I was turning the AC on and off probably so fast that it confused the fan controller . went out about 10 miles this morning and the AC worked fine and NO noise from the controller and AC worked fine. Thanks very much to all . happy weekend. Davie the bands are 10fm and 6fm

[n3chu]

Will, I put a .01, .001 and took off the 8000uf cap and put a computer grade 2900uf all in paralell and it is completly quiet. except for a few computers that I might pass along the road It is Fixed. It was the red power lead on the Stribel fan controller just as you said. Thank you Will (it only took me 10 years to fix it. I appreciate your help. Davie