AM directional info

[secondchoice]

I am looking at an AM directional in a non rated market LMA. IIRC there were 2 technical "classes" of directional. Is there an "easy read" on AM directional. I not after anyone's job, if things work out I will hire a real engineer to it look over. I just want to have a "big picture" idea of what I am getting into.

BTW There is a silent FM translator about 10 miles away which will have be secured first.

 

[TomT]

Not sure what you mean about two classes of directional AM's. There are several classes of Am stations, most newer full time stations as well as day time stations use the directional pattern to protect older stations.

There are differences in installations. All directional stations use sampling systems to indicate whether the antenna system is operating normally. Some of the sampling systems on very old stations have been grandfathered in to meet current FCC requirements.

Usually the problem at many small market directional AM's is not the type of sampling but that what ever is now in use is broken or needs extensive maintenance to bring back into spec.

 

[Bengalsfan]

I am looking at an AM directional in a non rated market LMA. IIRC there were 2 technical "classes" of directional. Is there an "easy read" on AM directional. I not after anyone's job, if things work out I will hire a real engineer to it look over. I just want to have a "big picture" idea of what I am getting into.

BTW There is a silent FM translator about 10 miles away which will have be secured first.

Hire a "real" engineer who knows AM directional antennas BEFORE YOU SIGN ANYTHING to go through it with a fine tooth comb. If the current owners refuse to let your engineer look at it, or if there are the slightest problems with it, RUN, don't walk, away. You have not seen how fast money can leave your bank account until you have a directional with problems on your hands.

 

[frankberry]

I agree with Bengalsfan. If there is an antenna system problem, it's likely that the sellers will attempt to hide it from you. Get an engineer who is experienced with AM arrays.
The two classes of DA systems are standard and critical. A critical array can be a headache to maintain as the nulls are very deep.

 

[Tom Wells]

And the more tight and directional the pattern, the more stress there is on tuning and phasing switches and especially roller
inductors. I'd want to SEE them actually tuning and "touching up" the currents and see if anything wacky happens at certain
spots in the tuning/phasing adjustments. If it works OK, they'll probably show you that.
If there's a problem, they will likely not want to talk about the issue.

 

[mikepattn]

The FCC no longer considers any array "critical"--that designation has been abandoned.

I agree with the others; you can spend yourself and your children into the poor house trying to fix a broken AM DA, especially in a small town, where your ability to generate cash flow to refill your coffers is, as a rule, strictly limited.

In fact, I tell my clients not to even consider buying an AM DA station outside of a top-100 market, and nothing over 2 or 3 towers outside of a top-60 or so. You can easily spend more than the station will ever be worth. I know; my firm has built and rebuilt many DAs. None of them were cheap to fix or build.

Like Richard Branson said: "How do you end up with a billion dollars in the airline industry? You start out with two billion!"

Having said all that, if you need anyone to do a due-diligence inspection, contact me privately; I can suggest several seasoned pros at that.