[BC] Diplexing an AM antenna.

[Jerry Mathis]

Answers embedded below.

On 4/30/07, Ronald J. Dot'o Sr. <ron.doto at comcast.net> wrote:
>
> Hi Gang,
>
> I'm about to take on a job I've never done before and would be grateful
> for
> any advice.
>
> I'm under the impression that a diplexer is like a double ATU with filter
> traps to couple each station to the tower while rejecting the other
> station
> from the respective transmitter's output.



You are correct in your assumption.


Is it very different from tuning a single ATU for each respective station?



If the traps are already properly tuned, then the answer is no.


Any suggestions on who to get the diplexer from?  Do they usually provide
> detailed tuning instructions?



I cannot recommend Kintronic Labs highly enough. They designed the one I use
here in Tupelo MS. It works very well, and crafted with high quality. They
can probably set the traps at the factory, but the two ATU's will need
tuning, as they cannot predict exactly the tower impedance.
   If you have not done this before, nor have the proper equipment, I'd
suggest you employ the services of a competent Consulting Engineer. There
are many on this List.

HTH

JM


The frequencies are 1220 and 1490, both 1 Kw. class C's.  I don't know what
> the tower resistance is yet.
>
> Thanks for any help,
>
> Ron D.
>
>