Carl Blare

The fascinating experience of learning how to use the new AMT5000 transmitter from sstran.com has brought the question of antennas foremost to mind, for the obvious reason that the antenna is so essential in disseminating a radio signal into the surrounding air.

The perfect starting point for me is this description of the Ultimate Part 15 Installation, written by PhilB earlier in the year:

http://www.part15.us/index.php?q=node/2728

In his posting, Phil is talking about classic antenna practice for AM radio, a proven and standard set of practices.

The trouble for Part 15 is that the typical setup is in a home or apartment, and the more industrial step of devoting real estate and somewhat of a big dig to locate an ideal 3-meter stick on cleared ground is not often an option.

Therefore something less than ultimate is needed, something of a compromise.

Indoor antennas are a common reality for many Part 15 radio stations, and this brings the question: what are the best designs for indoor AM antennas?

When I first started Part 15 about 6-years ago I used a glue stick to run the “white wire” 3-meter antenna up the same corner of the room where the transmitter and audio source were located (computer). Typical room height in most homes is less than 3-meters, about 8.5-ft.

The corner was chosen for proximity to the equipment, and neatness, because a white wire in the corner of a white room is very inconspicuous. But would the antenna have served better moved away from the corner, farther toward the middle of the wall?

The wall is the most likely place for a vertical indoor antenna, but would it work better moved into the room, away from the wall, perhaps by hanging from the ceiling alongside a floor lamp or other furniture?

Basement transmitter locations usually utilize horizontal antennas, and there are attic installations.

No full power radio station would ever place its antenna indoors, therefore no standards have been developed for such practice, but Part 15 is an exceptional circumstance, and indoor antennas are part of the game.

The question is, what are the best designs for including a 3-meter vertical antenna within home furnishing.

Previous mentions of using slinky toys as antennas, and they are helical in form, caused me to ask my consultant where I could find a slinky. She was certain that Walgreens would always have slinkies as kind of a standard item, so there I was walking up and down the toy aisle again and again. Then I spotted the little Slinky boxes, but darn the cheap life we have in the devalued world…. they were plastic!

On the way out I spoke with the very pleasant attendant and she was up on her shelf knowledge, and knew they were plastic. She thinks the “bigger” department stores will have metal slinkys.

Once I have them, I’m stretching a group of four of them 10-feet top to bottom in a helical cage monopole design. That should carry this station into the fame it deserves.

I’ll admit that the closest thing to liking sports that I know is doing things in the wrong order. For example, I am notifying you that Low Power Hour # 14 is published.

I’ll admit that the closest thing to liking sports that I know is doing things in the wrong order. For example, I am notifying you that Low Power Hour # 14 is published.

However, I haven’t uploaded anything yet to my website.

The sport of it starts now. Can I get the stuff uploaded before you read this and go looking for the audio file.

This plasma speaker rekindles earlier notice of a plasma antenna which seems like it could have applications for Part 15.

http://www.instructables.com/id/Build-A-Plasma-Speaker/

This plasma speaker rekindles earlier notice of a plasma antenna which seems like it could have applications for Part 15.

http://www.instructables.com/id/Build-A-Plasma-Speaker/

This second link is a report on the current state of the art of plasma antennas:

http://faculty.nps.edu/jenn/pubs/plasmareportfinal.pdf

The final link shows my original posting on this subject, and the link there is interesting too:

http://part15.us/node/1840

There are two production projects to talk about, the first one has to do with announcements which post our operating frequencies and FCC provisions for legal operation, the second are a sly way of filling time to make things come out by the clock, and also imitating the atmosphere of WWV or other time station.

I hope these samples are interesting and maybe inspiring.

KDX has found a schedule that enjoys the best of both worlds.

KDX has found a schedule that enjoys the best of both worlds.

At night and in the morning it’s so peaceful to have complete silence, without the racket and yack of morning radio & TV. Also, it’s a joy to hear the carrier first come on over the ambient radio background noise, and the reverse at night, when the carrier shuts down and leaves only the far away buzzle (a new word).

HOWEVER, acting big and important works out on weekends and holidays when KDX goes 24-hours with solid around the clock programming.

There are 7-billion people in the world who right now are missing the great programming on KDX, although some of them are listening to your stations. But think of how well off they are to have such great programs to miss.