Part 15 AM Antennas

[rfry]

> Standard, legal-length antennas *are* either supplied with
> FCC-certified units such as the Talking House and
> TalkingSign (3 meter wire antennas) and/or standard consumer
> antennas are specified for use with them (2.59 meter [102"]
> tall CB whips are used with the RangeMaster, the Talking
> House & TalkingSign outdoor ATUs, and the out-of-production
> Trans-AM). -- JasonW
_________________

Even if the Part 15 certification was made on a tx including its antenna, its operation will not meet the conditions of the certification if the antenna system no longer meets the Part 15 length requirement when the system is installed.

This is the case whenever a Part 15 AM tx and ~3 meter, supplied antenna is elevated above ground level, and uses a long conductor (some combination of a ground lead, ground wire, tower, or any conducting path) to connect the tx chassis to physical earth.

Rangemaster even publicizes this idea by showing an installation sketch on their website of a Rangemaster on top of a house, with a wire path leading to a ground stake below. The wire to ground becomes part of the radiating structure of the antenna, and this longer radiator (whip + connection to earth) increases the field strength that the system can produce. If it didn't do so, this kind of installation would not be so popular with Part 15 AM users.

This is not a personal opinion, belief or understanding. It is an engineering reality that can be demonstrated and proven scientifically.
//

 

[WCWalker]

***According to my discussions with several FCC people there is nothing in the rules that prohibits someone from mounting a transmitter up in the air.

What the FCC defines as the antenna and what you define as the antenna appears to be just a bit different.

Do you take perverse pleasure in being an antagonist?



> > Standard, legal-length antennas *are* either supplied with
>
> > FCC-certified units such as the Talking House and
> > TalkingSign (3 meter wire antennas) and/or standard
> consumer
> > antennas are specified for use with them (2.59 meter
> [102"]
> > tall CB whips are used with the RangeMaster, the Talking
> > House & TalkingSign outdoor ATUs, and the
> out-of-production
> > Trans-AM). -- JasonW
> _________________
>
> Even if the Part 15 certification was made on a tx including
> its antenna, its operation will not meet the conditions of
> the certification if the antenna system no longer meets the
> Part 15 length requirement when the system is installed.
>
> This is the case whenever a Part 15 AM tx and ~3 meter,
> supplied antenna is elevated above ground level, and uses a
> long conductor (some combination of a ground lead, ground
> wire, tower, or any conducting path) to connect the tx
> chassis to earth ground.
>
> Rangemaster even publicizes this idea by showing an
> installation sketch on their website of a Rangemaster on top
> of a house, with a wire path leading to a ground stake
> below. The wire to ground becomes part of the radiating
> structure of the antenna, and this longer radiator (whip +
> connection to earth) increases the field strength that the
> system can produce. If it didn't do so, this kind of
> installation would not be so popular with Part 15 AM users.
>
> This is not a personal opinion, belief or understanding. It
> is an engineering reality that can be demonstrated and
> proven scientifically.
> //
>

 

[JasonW]

> Even if the Part 15 certification was made on a tx including
> its antenna, its operation will not meet the conditions of
> the certification if the antenna system no longer meets the
> Part 15 length requirement when the system is installed.

The RangeMaster uses a 2.59 meter CB whip and has a ground terminal on the transmitter case. As long as the antenna + ground *lead* length is no more than 3 meters, it's legal. The ground itself (what the ground lead is attached to) isn't specified in the rules--metal billboards have been used, inspected by FCC field agents, and approved as legal. The Talking House and TalkingSign have the same arrangement (2.59 meter CB whip and ground terminal) on their outdoor ATUs. All three of these transmitters and the ATUs are FCC-certified.

> This is the case whenever a Part 15 AM tx and ~3 meter,
> supplied antenna is elevated above ground level, and uses a
> long conductor (some combination of a ground lead, ground
> wire, tower, or any conducting path) to connect the tx
> chassis to earth ground.

Using a 1/4 wavelength counterpoise wire is, of course, illegal. Using large metal objects and towers is legal. Bill Blew's tower-mounted RangeMaster operated with the FCC's blessing, and if I recall correctly, his local FCC Field Office even praised his engineering skills in devising his installation.

> Rangemaster even publicizes this idea by showing an
> installation sketch on their website of a Rangemaster on top
> of a house, with a wire path leading to a ground stake
> below. The wire to ground becomes part of the radiating
> structure of the antenna, and this longer radiator (whip +
> connection to earth) increases the field strength that the
> system can produce. If it didn't do so, this kind of
> installation would not be so popular with Part 15 AM users.

These types of installations (as well as "whip-and-mast" set-ups) have been inspected by FCC Field Agents, and some have passed (or not) on a case-by-case basis. For DC grounding alone, there has to be a connection to ground. If FCC Field Agents say a particular installation is okay, what's it to you? -- JasonW

 

[rfry]

> Do you take perverse pleasure in being an antagonist?

I do my best to write with scientific accuracy. Using science with Part 15 equipment should not be antagonistic to anyone wanting to understand the true performance of the equipment they are using.

The alternative is to rely on hearsay, guesswork and wishful thinking.
//

 

[WCWalker]

Well, again, obviously you don't see things the way the FCC does. Clearly you have not dealt with them on part 15 station issues otherwise you would not be feeding us this tripe.

You said:

The alternative is to rely on hearsay, guesswork and wishful
> thinking.

Precisely what you are doing.

 

[dickfry]

> > Do you take perverse pleasure in being an antagonist?
>
> I do my best to write with scientific accuracy. Using
> science with Part 15 equipment should not be antagonistic to
> anyone wanting to understand the true performance of the
> equipment they are using.
>

No you don't. Having your OPINION become the law is much more important than science or you wouldn't be here all the time trying to harass us with yet another scientific OPINION. A scientist would give us the facts and let us stew in them. Instead, we get constant reiterations of why we're wrong and you're right. So shut up already. We GET it.

> The alternative is to rely on hearsay, guesswork and wishful
> thinking.
> //

No, the alternative is applying science to the REAL WORLD. There's a word for that, and it's Technology. Science exists in a vacuum. Technology is a real world application of the science. Funny things happen when science meets application.

-Dick

 

[rfry]

> Technology is a real world application of the science.
> Funny things happen when science meets application.
______________

I wouldn't call them "funny." I would call them commercially valuable.

I say that because for the last 34 years before I retired I worked as a field and applications engineer for the two largest manufacturers of broadcast transmitters in the US (15 yrs at RCA, then 19 years at Harris Corp).

//

 

[WCWalker]

***Well R. Fry, actually I respect your abilities and experience. It just so happens most of my best friends are engineers of some sort including broadcast. However, you are attempting to look at part 15 broadcasting in the same light as higher powered broadcasting. While it is not like comparing apples to oranges it is like comparing a Cortland apple with Granny Smith. Some differences exist yet both are essentially the same. Believe it or not some of these very same friends of mine were able to learn a thing or two about part 15 AM from yours truly because they found their own background didn't truly translate very well over to part 15. Now, they are ahead of me after having been able to learn the in's and out's for a few years.

What disturbes me about your position on the issue at hand is that you just won't listen to real world experience of people that have been through it and have dealt DIRECTLY with the FCC. You base your OPINIONS on some document you find on the internet. The station in California was using a 20 to 30 watt LPB type unit. Same thing for that station in Boston. The Flagstaff station was using a Rangemaster but got the ground issue resolved and they are now back on the air.

Your conceited arrogance is akin to a green, college boy 2nd Lieutenant in the Marines attempting to lead a group of seasoned Marines into combat. A smart college boy would let his lead Sgt. handle it and he would stay to the rear to learn how to deal with real, on field experience. Your ego won't permit that.

Your experiences and expertise in full power broadcasting are to be commended. But until you start running your own part 15 station with a Rangemaster or some other unit, experiment with it and see what you can do with it while remaining legal, I take what you say with a grain of salt. Equally disturbing is the fact that you don't even take the word of someone that has dealt with the FCC on this matter before or the word of other people that have as well. Clearly, I am beginning to question your own personal character!


> > Technology is a real world application of the science.
> > Funny things happen when science meets application.
> ______________
>
> I wouldn't call them "funny." I would call them
> commercially valuable.
>
> I say that because for the last 34 years before I retired I
> worked as a field and applications engineer for the two
> largest manufacturers of broadcast transmitters in the US
> (15 yrs at RCA, then 19 years at Harris Corp).
>
> //
>

 

[KeithHamilton]

Using a ground wire is NOT a problem, all Part 15 doesn't have to be mounted on the dirt, all ground doesn't have to be the dirt, it just isn't the real world. It's one thing to belive it yourself but spreading it around when it just isn't true (I think you have to much time on your hands) is destructive. I will not respond to any more fray about this issue, I am to busy to repeatly deal with this issue coming from the same people. if anyone has any questions contact me directly but take my word, setups are passed all the time with ground wires, the ground terminal does NOT have to be in the dirt. This is just not practicle for people in cities or apartments, those people can't even find the dirt! Something other then the dirt has to be allowed to be ground.

The main reason a decent ground system needs to be allowed is lightning protection. Our unit (don't know about others) has a lightning protection system that requires a ground system as decribed in our manual to operate properly. When our customers hear (from SOME) that the suggested system may not be OK they are tempted to run the system with NO ground connection (say if they are in a 10th floor apartment or such)which removes the lighting protection! Where should I have a customer send the bill when he has lightning damage to his house or building because he was scared into not properly ground his transmitter?

 

[rfry]

Keith Hamilton wrote:

> all ground doesn't have to be the dirt, etc

But at radio frequencies, true ground conditions aren't present along any conducting path of any height above physical earth. Therefore a long conducting path to/from the earth (often called a ground WIRE by Part 15 users) does not have the r-f characteristics of the earth until it gets to its connection point to the mass of the earth itself.

All of the r-f current that can flow in the loading coil and 3 meter section (including the short "ground lead") of an elevated Part 15 AM antenna first has to travel up from physical earth through that long, conducting path consisting of what is called the ground lead AND the ground wire.

The net result of the realities of the above two paragraphs is that a long ground wire as used with a Part 15 AM tx on an elevated mount DOES RADIATE -- often many times more field strength than produced by the 3-meter part of the antenna above it.

Please verify my statements using any authoritative sources you wish (engineering texts, broadcast consultants, university professors etc). I'm sure that you, as an ethical, commercial businessman, want to give technically accurate applications information to the buyers of your Rangemaster transmitters.

//

 

[WCWalker]

***R. Fryd, you are positively as dense and shallow as the people that live in western NY. They can't see or think beyond the shallow little cubby hole of hell that they call home. All that matters on this issue is what the FCC will and won't allow. Simple as that.

Keith Hamilton has sold a lot of transmitters over the last few years and the FCC has never shut down any station using one his transmitters or those that employ the methods of technical wisdom that he imparts on his website.



> Keith Hamilton wrote:
>
> > all ground doesn't have to be the dirt, etc
>
> But at radio frequencies, true ground conditions aren't
> present along any conducting path of any height above
> physical earth. Therefore a long conducting path to/from
> the earth (often called a ground WIRE by Part 15 users) does
> not have the r-f characteristics of the earth until it gets
> to its connection point to the mass of the earth itself.
>
> All of the r-f current that can flow in the loading coil and
> 3 meter section (including the short "ground lead") of an
> elevated Part 15 AM antenna first has to travel up from
> physical earth through that long, conducting path consisting
> of what is called the ground lead AND the ground wire.
>
> The net result of the realities of the above two paragraphs
> is that a long ground wire as used with a Part 15 AM tx on
> an elevated mount DOES RADIATE -- often many times more
> field strength than produced by the 3-meter part of the
> antenna above it.
>
> Please verify my statements using any authoritative sources
> you wish (engineering texts, broadcast consultants,
> university professors etc). I'm sure that you, as an
> ethical, commercial businessman, want to give technically
> accurate applications information to the buyers of your
> Rangemaster transmitters.
>
> //
>

 

[oldies1077]

Mr. Richard Fry also posts to Broadcast.net "Radio Tech" Listserv. He behaves just as Moronic and Dense there also whenever part15 subject arises. He will not only beat the horse till it's dead, he will beat until it's 20ft down in the mud. Let's all ignore his posts and he will go away.<P ID="signature">______________
Oldies 1610 AM Stereo

"Proud User of Chris Cuff's Alfredo Lite 100mw"

http://www.part15.us
Largest Part 15 Website in the World</P>

 

[JasonW]

Don't feed the troll (Re: Part 15 AM Antennas)

> Mr. Richard Fry also posts to Broadcast.net "Radio Tech"
> Listserv. He behaves just as Moronic and Dense there also
> whenever part15 subject arises. He will not only beat the
> horse till it's dead, he will beat until it's 20ft down in
> the mud. Let's all ignore his posts and he will go away.

A big AMEN to that! Newsgroup and message board trolls are like feral cats--they only hang around as long as someone continues to feed them. I will do so no more. -- JasonW

 

[KeithHamilton]

Re: Don't feed the troll (Re: Part 15 AM Antennas)

Amen too! There are some topics that we can go around the mulberry bush for hours about, I don't have the time.

 

[dickfry]

> Please verify my statements using any authoritative sources
> you wish (engineering texts, broadcast consultants,
> university professors etc). I'm sure that you, as an
> ethical, commercial businessman, want to give technically
> accurate applications information to the buyers of your
> Rangemaster transmitters.
>
> //
>

I hear a dog barking but I don't think it's saying anything. Probably it just gets lonely and likes to hear itself bark.

-Dick