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Author Topic: MFJ 1025 Noise Canceler: Noise antenna info  (Read 222 times)

KF7ZFC

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MFJ 1025 Noise Canceler: Noise antenna info
« on: October 01, 2020, 06:04:55 AM »

The MFJ 1026 instructions do not give any info on guidelines for length, type etc. for the noise antenna.

What have users of the MFJ 1025 been successful with?

Thanks
Steve
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KX2T

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Re: MFJ 1025 Noise Canceler: Noise antenna info
« Reply #1 on: October 01, 2020, 07:26:09 AM »

I have had the use of the 1025 since 2017 when I moved into a home with a small lot plus surrounded by utility wires were the RFI noise was over S9+10 on almost ever band except for 6 meters were it was only S9.  First I used a low long wire going parallel with the utility lines but not directly underneath that would be used as the noise sense antenna, then I could bring that noise down to an S3-4, eventually the power company found the issue and I almost didn't need it until a home which was 400 yards away from my qth installed solar panels and then were back to the S9 BS all over again.
Fast forward to just over a year ago we moved down to the west coast of Florida and guess what that S9 noise was back but down here the RFI division of FPL was able to get to the poles that had insulator issues within two months but down here I used a different type of noise sense antenna which was a 36ft vertical with one radial of equal length which seems to pick up the noise much better and I am able to get a positive null when I rotate the phasing control on the noise, the vertical seems to pick up any noise much better than a horizontal antenna and yes I know what the book says but sometimes you should think out of the box and it has paid off. FPL did get the noise to go down but on the mower bands it does help at times cause I can take at night an S5 background noise level down below S2 or even one at times, yes you may lose a little on your S meters reading but the signal to noise level improvement is worth 100 times more in solid copy. It doesn't really help when thunder storms are near by but when they are further away it helps attenuate them to an extent.
I don't know exactly how this may work for your qth but you may give it a try cause with the vertical noise sense antenna I was able to almost reduce the RFI coming from the electrical poles during the day to S1 on 40 meters were just before sunset it makes copy of allot more DX then not being able to hear them when the noise level is higher, your mileage may vary but these boxes do work.
I did modify my box on the input of the noise antenna I placed a relay that shunts that antenna input to ground when you go to transmit cause that little wheat grain bulb is BS but what do you expect after all its MFJ. Also since I went with using the vertical as the noise antenna the settings don't really change a whole lot when you change bands like when I use a horizontal noise antenna.
Good Luck
Jim
KX2T
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KF7ZFC

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Re: MFJ 1025 Noise Canceler: Noise antenna info
« Reply #2 on: October 01, 2020, 08:21:54 AM »


Jim:
Thanks

Steve
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