Topband: Noise canceller

[Tree]

On Fri, Dec 21, 2007 at 12:16:32PM -0500, Peter Dougherty wrote:
> I just ordered a 1026 last night, which will hopefully will arrive in 
> a few days. What do I need for a sense antenna if my primary problem 
> is S9+ AC power line noise?
> 
> The other question I have is how to connect this to my antenna 
> system. I have bad line noise on 80 for the most part (160 is clean 
> by and large), but occasionally it gets bad on the upper bands as 
> well. I'm wondering if I should just hook this up to my K9AY loop (to 
> the AUX in port on my Mark V), or if I should put this on a switch 
> somehow and and pass my TX antenna through this as well?

Hi Peter.

You can just hook it up like how I use my 1026.

I use it for two purposes:

1. Switching in my RX antenna.
2. Noise cancelling.

Put it in the transmit coax and hook up your RX antenna as the auxiliary
antenna.  For normal use of your TX antenna - just leave the unit off.

To use you RX antenna - turn the unit on - and leave the MAIN antenna
gain at zero.  You are now using your TX antenna on TX and your loop on
RX.

IF you get into a situation where you need to null out a local nose 
source, you will need to increase the MAIN gain some and then find the
right phasing to null out the noise.  

1. Note the S meter reading of the noise on the RX antenna only.
2. Turn the AUX gain to zero and adjust the MAIN gain so the noise
is about the same s-meter level.
3. Return the AUX gain to full.
4. Now play with the phasing until you find a null.
5. Fine tune the controls to get a deep null.

I am currently dealing with a new power line noise about a mile away that
I can just about totally eliminate with the above process.

So - you already have all the antennas you need.

I would suggest feeding a PTT signal to the MFJ if possible.  This 
eliminates any hot swtiching and allows you to minimize the "drop out
delay" when you are done transmitting.

73 Tree N6TR
tree at kkn.net