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Bert, When using the RF Systems Balun you should use a normal coax with PL-269 fittings attached in the standard fashion. Inside the MLB are two special ferrite cores separated from one another by a thin plastic material. This core separation is what allows for the "quieter magnetic component" (as apposed to the electronic component) of the RF signal to transfer to the bottom core & then down the center conductor of the coax to the receiver input. This is just what you want with one minor modification.
The real problem you are over coming with the use of that very good balun (I use them on all of my antennas) is "you are isolating the braid on the coax from being just one more part of the antenna system"! When you attach a normally attached PL-259 on the coax you are "creating a short" on the braid as you screw on the coax fitting. Why? The winding on the balun core has one leg attached to ground, the part the PL-259 screws onto.
Now, when you attach the receiver end of the coax to the receiver you create another short of the coax braid. Remember, the coax braid is metal and will act as just part of the antenna (a noisy part at that) unless the braid is properly terminated (shorted out) at both ends. (I could get more complex hear but for the sake of simplicity will not). When regular coax is used this way the ground at the receiver end is dependent on the validity of the receivers & your home ground system for proper function. So, to attach a small part of the coax braid to a ground rod about 3 or 4 feet from the receiver will provide better isolation & ground.
I hope this is clear enough. Just use good coax & add another braid ground just prior to the receiver. You'll hear the difference! Coax used absent a balun & termination is a waste of money.
73 John T. Wagner, Ohio
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