WARM

AM Radio discussion. Directional arrays are FUN!
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Deep Thought
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Re: WARM

Post by Deep Thought »

Augmentations (technically, modifications to the standard pattern) are a way to "draw in" areas of an AM directional pattern to cover anomalies the normal pattern calculation doesn't account for. These are usually null areas or places where a lobe exceeds the expected field strength. There is a specific process defined in the FCC Rules that allows for computer calculation of this, and those parameters (azimuth, span and field intensity) are what you see on the license as augmentations.

The original purpose of it was to allow for hand-calculated patterns to be computerized when the Commission changed to the current Standard Pattern methodology in the late 1970's. They went through all of the then-licensed directional antennas and sent out proposed Standard Patterns for each, and the stations had a chance to counter with their own modifications. Some old patterns were extensively modified and have a couple dozen augmentations to get it inside the computer pattern. It was a nice little windfall for consulting engineers at the time.

We use them now when re-radiation causes problems with pattern adjustment and the resulting "out" radials would not cause interference.
Mark Mueller • Mueller Broadcast Design • La Grange, IL • http://www.muellerbroadcastdesign.com

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Re: WARM

Post by ai4i »

Deep Thought wrote:Augmentations (technically, modifications to the standard pattern) are a way to "draw in" areas of an AM directional pattern to cover anomalies the normal pattern calculation doesn't account for.
Interesting, does this apply to parallelograms, too?
Endfires with 90° spacing and broadsides with any spacing do seem like pretty standard stuff repeated hundreds of times, everywhere. I would guess that a parallelogram would be a much more customized beast right from when the towers are positioned on paper (or now, a screen).
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Deep Thought
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Re: WARM

Post by Deep Thought »

It applies to the pattern calculation regardless of the array geometry or the number of towers. We calculate everything based on the formulas in Part 73 (47 CFR 73.150 and 47 CFR 73.152). The augmentation process just lets us adjust for the real world as necessary.

Parallelogram arrays are just another day at the office. :)

There are also 'random placement' arrays where all four parameters are varied (field ratio, phase, spacing and orientation) along with the antenna height to suppress radiation at certain bearings and vertical angles. Those get to be rather interesting but the math is always the same.
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Re: WARM

Post by ai4i »

Deep Thought wrote:...just another day at the office. :)
You seem to understand this for the science that it is, rather than the art many of us wish it were!
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Deep Thought
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Re: WARM

Post by Deep Thought »

It is both an art and a science and is how I've supported myself for the last 26 years... 8)

And then when you try to make it happen in the field...it turns into voodoo. I am in that position right now with a very cranky new four tower array which just does not want to give up the last six percent of field ratio on one tower to get it 'in'. We'll be sacrificing rubber chickens over the phasor soon...

At least I can look for Perseids while I'm walking between towers in the middle of the night. :lol:
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RGORJANCE
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Re: WARM

Post by RGORJANCE »

Don't forget to place the mirrors properly when evoking the "voodoo" technique.

Fossil

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Shane
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Re: WARM

Post by Shane »

Does it work if you use rubber chickens? I thought you had to use actual ones.

A "cranky array" eh? I bet in more ways than one.

Any news on WARM? Are they on? Radio-locator, which seems to have a knack for knowing when a station is not on the air, has not listed WARM as such.
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Re: WARM

Post by ai4i »

A child in the nineteen sixties, we visited with relatives in Carbondale, sixteen miles east northeast of Scranton.
Must have been in their null at night, remembering that WABeatleC sounded at least as good. From the looks of their map, purhaps they should be transmitting from a few miles north northwest. WARM-land was undoubtedly much smaller "back in the day".
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Re: WARM

Post by Shane »

I remember getting off the Turnpike extension at the last exit by Clarks Summit and experiencing one of those nulls, although the signal was still generally quite strong. According to how it looks on the map, Carbondale would have been in the same general direction. I remember being a little disappointed that the signal was nulling out at a point so close to the metro area when I could usually hear it quite clearly - though not strongly, of course - at the Jersey Shore.

WAEB used to and maybe still does have a null in the night pattern that goes almost right down Cedar Crest Blvd on the west side of Allentown and totally misses Nazareth to the east. It's funny that they both might be improved by actually moving a little further away from town, if they can still get enough signal into the COL.

I found WARM's STA to remain silent on the fcc.gov site so I guess it's still off. The ex date on it was 10/15/09 IIRC.

< < Find yourself a 250' tower in the center of the market (that's the minimum height for this frequency) and you can cover about 300,000 inside the 5 mv/m. > >

There's a 292-foot tower on top of a building in downtown Scranton. I suppose 630 is too close to diplex with 590, though.
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Re: WARM

Post by eadler »

Just picking up noise on 590 kHz here...
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Re: WARM

Post by Kelly »

Augmentations are in essence, alterations to what would be considered a "Standard Pattern" usually after the original filing or license was accepted. For example, say you end up with a back lobe from a cardioid pattern, but it doesn't increase the RSS toward the protected direction enough to increase interference, but the new or calculated shape helps better form the overall pattern. One would file for augmentation to the CP or license.

There are other examples, but I've got a lot of E-mails to answer this morning and don't want to risk carpel tunnel syndrome...
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