[RFI] COMM0N MODE NOISE OBSERVATIONS AND REPAIRS

[Dxhogg at aol.com]

i had posted about a week ago about common mode noise and what  i had thought 
was a really awesome "repair". well the repair really works but  along the 
road of determining what was really at play creating all the different  noises i 
have discovered all of the problems in the station was of poor  
infrastructure. i had originally wired the operating position all station  grounds and 
interstation cabling about 18 years ago. well to put i in simple  terms it was all 
junk. wall warts, braided cable for grounds, and poor quality  coax were the 
real culprits.pay extra attention to ground loops.wall warts are a  prime 
cause of ground loops cut all the cables off the warts and use only the  cable  
and use a good quality 10 amp power supply for all the ancillary  station 
equipment. multiple antennas and feed lines should all be kept  galvanically 
separated from one another till the cables are connected at your  main station 
bulkhead what i mean by separated is don't use the ground for a  160m lnv l as a 
tower ground 
ect...look at your station layout in a ground loop aspect you  will be amazed 
at isolating these problems clean up the noise floor. i had a  terrible noise 
on 160m that seemed to follow the resonant FREQ of the transmit  antenna when 
i would disconnect the open wire feed from the tuner the noise on  the 
receive antennas would disappear.....well it turns out that in 1945 when  tech 
material corp built this unit using braid as interconnecting leads was  cool  not 
so my tuner was a rebroadcaster....all the junk braid replaced w  1/4 inch 
tubing and quiet bands again...this is a wake up call look at your  station your 
neighbors wifi  stuff my be heard because of a rectifying  joint in your 
station...simple things like coax connectors with the shield not  soldered correctly 
will cause a hell of a lot of  problems      dx  on   ray  nr1r