Measuring Pt 15 AM Field Strength

[WCWalker]

***Yep, another smart alec.

Note: If you have something meaningful to contribute to the discussion then by all means do so.



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> -.. .-.. .. -.- . - --- ... . . .. - -.-. --- -.
> -.. . -- -. . -.. - --- .... . .-.. .-.. .-.-.-
>
> Note, if you translate the morse code to english, you may be
> able to figure out why I didn't write the post in plain
> english.
>
> > ***You are a cretin. I sincerely apologize for having to
> > stoop to this level but it is quite apparent that you are
> > sounding like a broken record. Worse still you are
> > incapable of understanding the interpretations of the
> FCC's
> > rules by the FCC in Washington.
> >
> >
> >
> >
> > > > ... 15.209 ... is an ancient rule that
> > > > no longer seems to be enforced.
> > >
> > > > ... from what I have been told
> > > > by people at the FCC and others ...
> > >
> > > > ... to my knowledge,...
> > >
> > > > I have not heard of one single instance ...
> > >
> > > etc.
> > >
> > > How much help would your statements be to someone who
> was
> > > cited by the FCC after operating according to your
> > beliefs?
> > > //
> > >
> >
>

 

[carlvanorden]

> > This assessment is incorrect. If the field strength from> a> > Part 15 AM system can't be distinguished from ambient> noise> > in the AM band by a professional field strength meter,> then> > a normal radio receiver couldn't do it, either. So then> why> > would anyone want to operate a Part 15 station?> > A field strength meter (and I've built a few) only provides> an indication of the voltage present at its antenna> terminals, regardless of the form of RF producing the> voltage (white noise, AM, FM, SSB, video, etc.) at the> frequency at which the field is being measured. Most of the> noise one hears on an AM receiver (transformers, computer> monitors, fluorescent lights, etc.) is quite short-range in> nature, and it is easy to isolate the receiver from these> noise sources or simply null them out by rotating the> receiver. Because of this, it is not difficult to receive> Part 15 AM signals even in such an environment.> > > The certainty IS that if a Part 15 AM signal is strong> > enough to provide a useful (listenable) signal to any kind> > > of radio receiver, a field strength meter can measure that> > > signal strength with good accuracy. This is not an> opinion,> > it is a provable fact.> > I have reproduced what happened to William myself. With all> of the local noise impinging upon the field strength meter's> antenna, the meter needle didn't visibly move at all with my> Part 15 AM transmitter on or off. The transmitter is> clearly audible on a pocket receiver up to 1/4 mile away. > > > "Beliefs" and "understandings" not based on this reality> may> > lead to operation of Part 15 AM systems in ways that will> > increase the risk of illegal operation, and possible FCC> > citations.> > Now, finally, we're down to brass tacks. When operated> according to the three simple rules (antenna + ground lead> length, power to the final stage, and harmonic suppression),> there is *NO* risk of illegal operation, despite *your*> beliefs. You have an inordinate interest in Part 15> broadcasting which parallels that of some anti-firearms> advocates I've had occasion to argue with. They were> embarrassed or afraid to come right out and say they opposed> the Second Amendment, so they attempted to obfuscate the> issue by being extremely nit-picky about local and state gun> laws. Like them, the tone of your postings suggests that> you don't think that citizens should have the freedom to> broadcast without a license at any power level. It doesn't> offend me if you feel that way--I just wish you'd come right> out and say it. -- JasonW> I attempted to stay out of this, but here is a bit of experience from the antenna guy.......look at my website and I show a very very simple, hand held FSM, that doesn't even require a battery.It looks like a very tiny walkie talkie and you can adjust it if you feel like it.....In testing my antennas, this meter will either jump, peak, or do nothing if I TOUCH the antenna of the FSM to my antenna. If it does something, I know I am on the right track to tuning my antenna right.......Truthfully no matter how excellent my signal was, this simple meter did very little of nothing just 10 feet away from a transmitting antenna....in fact if I saw any reading at all, I would be pretty happy that the antenna was well tuned......the signal of a part 15am, even on a very clear quiet frequency will be heard by a radio further away than any meter could even find...the FS just isn't there to detect.....Todays' consumer radios are just junk, and even if a part 15 does have a very good, perhaps 2 mile solid signal, it may be difficult to get inside a house, but better received inside a car...........................................................Lets take a fictional town, called Fryland. Fryland has NO AM stations anywhere around it, but John decides he is going to put up a part 15am station....John has his choice of any frequency he wants, so he installs his basic antenna in the ground outside his home. He rides the neighborhood and finds he has pretty nice reception in the local area. He decides he wants to increase his signal by hiking his antenna up over the house.....well, because AM is a ground based signal especially at this powerlevel, John doesn't get much further with his signal.....Joe the FCC agent happens to be on vacation, hears the station and stops by Johns house to check out this antenna.....He decides it is a nice signal and he isn't interferring with any commercial station......in fact Joe thinks, if John really wanted to, no one would be the wiser if he used an amp to boost his wattage......but even if he did, no local station would report him because there is literally no interference................................................................So, I'm wondering why, especially if a Part 15 am is constructed either EXACTLY to the letter of the law, or gets pretty close to it and it doesn't interfere with anyone (which is more important than anything else!) why it is suddenly a problem????>>>>>>>>>>>>>>>>Unless you are in an urban area, stepping all over a Class A (hehehhheheheeeee!!!!) I just don't see what the point here is!!If you are visited, show the agent your part 15 100mW tx, your legal length antenna (more than likely shorter than legal length!) and ask for an opinion.......if you are not interfering, he will need to move on to much more pressing problems......more of which he has than worrying about your walkie talkie signal.<P ID="signature">______________
[email protected], [email protected],[email protected]</P>

 

[rfry]

> I attempted to stay out of this, but here is a
> bit of experience from the antenna guy.......look at my
> website and I show a very very simple, hand held FSM, that
> doesn't even require a battery.It looks like a very tiny
> walkie talkie and you can adjust it if you feel like
> it.....In testing my antennas, this meter will either jump,
> peak, or do nothing if I TOUCH the antenna of the FSM to my
> antenna. If it does something, I know I am on the right
> track to tuning my antenna right.......Truthfully no matter
> how excellent my signal was, this simple meter did very
> little of nothing just 10 feet away from a transmitting
> antenna....in fact if I saw any reading at all, I would be
> pretty happy that the antenna was well tuned

FS meters such as the one you describe, and the commercially-built MFJ-801 (I checked) do not measure field strength in any calibrated way, and do not have the sensitivity needed to use with the the fields radiated from a Part 15 AM system. They give indications of relative field, but their sensitivity is inadequate to even sense those radiated fields unless they are extremely high, compared to what is needed by a normal AM receiver.

Accurately measuring field strengths in absolute terms for Part 15 AM systems requires active amplifiers and tuned circuits in the FS meter, a calibrated antenna, and a trained operator. A professional FS meter such as the FIM-41 can do that, given a skilled operator. Indicators such as the MFJ-801 cannot.

> ......the signal
> of a part 15am, even on a very clear quiet frequency will be
> heard by a radio further away than any meter could even
> find...the FS just isn't there to detect

True for the FS meter you described, but not true for a professional quality FS meter such as the Potomac FIM-41 (similar, if not the same as what the FCC would use). It can measure any signal to levels equal and probably below that which provide a useful (listenable) signal to a normal AM receiver.

> take a fictional town, called Fryland. Fryland has NO AM
> stations anywhere around it, but John decides he is going to
> put up a part 15am station (etc)

This scenario simply steers people to install and operate whatever they think they can get away with. And I have no problem with anyone (but me) wanting to do that. My only hope is that those other people really know what they are doing, and are willing to accept whatever consequences that might follow.

//

 

[JasonW]

On the frequency I use (1600 kHz), there is always a constant "rushing" sound like that heard on a SW or CB radio tuned between stations, when my transmitter is off. When it's on, I get full quieting (if broadcasting carrier only) out to 1/4 mile on a pocket receiver.

All I'm using is a stock Talking House with the stock manufacturer-supplied outdoor ATU (with a locally-bought 2.59 meter CB whip specified in the ATU instructions) mounted atop an old stove in the backyard (the metal stove is the ground). It meets the letter *and* spirit of the law (it's actually better than required since the whip + ground lead length is *less* than 3 meters) . -- JasonW

> >In a typical neighborhood, the loop won't help much if at
> all
> >at Part 15 power levels because nearby noise sources (near
> the
> >transmitting antenna) are scattered in all directions.
> >In a neighborhood like mine where most houses have metal
> roofs,
> >reflections cause low-level background noise to be equally
> >strong in all directions.
>
> If at any location where noise cannot be minimized with
> respect to the Part 15 AM signal by rotating the loop
> antenna of a good field strength meter (FIM-41), then
> neither can it be minimized by rotating the loopstick
> antenna of a radio receiver at that location. And if the
> best received signal-to-noise ratio is 1:1, nobody would
> want to listen to that station, so trying to measure field
> strength there is somewhat pointless.
>
> Once again: if the Part 15 AM station can be heard clearly
> on a normal receiver at any location, then a suitable field
> strength meter like the FIM-41 will be able to measure its
> field strength there.
>
> >I was using an MFJ-801 Field Strength Meter at the time.
> >With the transmitter either on or off, its needle never
> moved,
> >although local noise kept its needle raised a little over 1
> "tick"
> >when set for maximum sensitivity (with the transmitter on
> or off).
> >I made measurements at the base of my 20' mast and from
> 15'away.
> >With the transmitter on, I could clearly receive it on a
> pocket
> >AM receiver at these same locations, as well as up to 1/4
> mile
> >away. With the transmitter off, I could also hear the local
> noise
> >on the receiver at the measurement locations and elsewhere.
>
>
> I'll try to find specs on the MFJ-801, but if it was not
> able to read the field strength while 15 feet from a
> radiating Part 15 transmit antenna, something was
> fundamentally wrong. Either the meter design doesn't have
> the sensitivity required, or maybe it wasn't working right.
>
> The field strength 15 feet horizontally from a good Part 15
> AM antenna system connected to a tx with 100 mW input power
> to the final RF amplifier should be greater than 5
> millivolts per meter. That is a substantial amount of field
> strength that a suitable field strength meter can easily
> read. And it is far above the ambient noise level even in
> city environments. Many AM broadcast stations have large
> audiences in areas where their signals are 1 mV/m or less.
>
> For confidence, here is a table of values showing calculated
> field strengths for the conditions shown, using the FCC's
> engineering data (sources on request).
>
> DATA:
>
> Frequency = 1600 kHz
> Tx Power Output = 80 milliwatts
> Radiator: Ground-mounted 3 meter vertical with
> a total of 20 ohms in ground and coil losses.
>
> Results:
> Contour level > Distance to contour
>
> 5.000 mV/m > 0.0032 miles (about 17 feet)
> 4.000 mV/m > 0.0040 miles
> 3.000 mV/m > 0.0054 miles
> 1.000 mV/m > 0.0161 miles
>
> //
>

 

[JasonW]

Only 10 ohms of ground loss in your model? Most of us Part 15 AM operators fervently *wish* our ground and coil losses were that low! As with any computer model, "garbage in, garbage out." -- JasonW

> RE: AM Field Strengths
>
> > How do you calculate those?
>
> It isn't real simple. First I modeled the 3-meter antenna
> on 1.6 MHz with 10 ohms of ground loss and 10 ohms of coil
> loss, using NEC (Numerical Electromagnetics Code). That
> gave me the groundwave field strength at 1 km for 1 kW of
> radiated power, which is the FCC "efficiency" for that
> antenna system.
>
> That antenna efficiency was then used with the FCC's
> propagation curves for that frequency to determine the field
> strength at those distances, for the given radiated power.
>
> > Also (this one anyone can answer), how would you
> > estimate/calculate ground/coil losses based on the ground
> > system used
>
> Coil losses can be measured with a suitable meter. Ground
> losses can be estimated indirectly by measuring the
> feedpoint impedance of the antenna, and subtracting the coil
> resistance and the radiation resistance.
>
> Radiation resistance also can be calculated (approximately)
> for these short antennas using this equation:
>
> Radiation Resistance in ohms =~ Height of antenna in
> degrees/312
>
> Note that the "height" here must include the 3 meter antenna
> itself plus the entire length of any conducting path leading
> from the tx chassis to the physical earth (that is, the
> ground lead, the ground wire, the tower, or whatever -- all
> of which when connected in series will form part of the
> antenna, and radiate).
>
> //
>

 

[JasonW]

Actually, William, he may have inadvertently stumbled across something we can use. Imagine not having to "bleep" out vulgarities in reports we broadcast on our stations--we can just substitute those very words in morse code! -- Jason

> ***Yep, another smart alec.
>
> Note: If you have something meaningful to contribute to the
> discussion then by all means do so.
>
>
>
> > .. - --- --- .- -- --. . - - .. -. --. ..-. . -..
> > ..- .--. .-- .. - .... .-. ..-. .-. -.-- .----. ...
> > ..-. ..- -.-. -.- .. -. --. .- - - .. - ..- -.. . -
> ---
> > .-- .- .-. -.. .--. .- .-. - .---- ..... .- --
> -...
> > .-. --- .- -.. -.-. .- ... - .. -. --. .-.-.- .. .--
> ..
> > ... .... .... . .-- --- ..- .-.. -.. - .- -.- .
> ....
> > .. ... .-. . ..-. ..- ... .- .-.. - --- -... . ...
>
> > -.-- -- .--. .- - .... . - .. -.-. - --- .--. .- .-. -
>
> > .---- ..... -... .-. --- .- -.. -.-. .- ... - . .-. ...
>
> > -.--.- .-- .... --- .-- .- -. - - --- -- .- -..- ..
> --
> > .. --.. . - .... . .. .-. .-. .- -. --. . ..- -. -..
> .
> > .-. - .... . .-. ..- .-.. . ... -....- .---- -----
>
> > ----- -- .. .-.. .-.. .. .-- .- - - ... --..-- ...--
>
> > -- . - . .-. .- -. - . -. -. .- .- -. -.. --. .-.
> ---
> > ..- -. -.. .-.. . .- -.. -.--.- .-- .... .. -.-. ....
>
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> -.
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>
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> .
> > .- .-. - .... --. .-. --- ..- -. -.. -.--.- -.--.- -
> ---
> > -.. .- -- -. . -.. .... . .-.. .-.. .-- .. - ....
> > .... .. ... ..-. ..- -.-. -.- . -.. -. .- -... -...
> ..
> > --. -... .-. --- .- -.. -.-. .- ... - . .-. ... ..-
> .--.
> > .--. --- .-. - .. -. --. ... -- .- .-.. .-.. -... .-.
> > --- .- -.. -.-. .- ... - . .-. -.-. .-. ..- ... .... ..
> -.
> > --. ... .... .. - .-.-.- .. .-- --- ..- .-.. -..
> > -... . --.- ..- .. - . ... ..- .-. .--. .-. .. ... .
> -..
> > - .... .- - .-. ..-. .-. -.-- .----. ... ..-. ..-
> -.-.
> > -.- .. -. --. ... .... .. - - -.-- .- - - .. - ..- -..
> .
> > .. ... .-- . .-.. -.-. --- -- . --- -. - .... ..
> ...
> > -.-. --- -- -- ..- -. .. - -.-- .-. .- -.. .. ---
> -...
> > --- .- .-. -.. --..-- .- -. -.. .. .-- --- ..- .-..
> > -.. .-.. .. -.- . - --- ... . . .. - -.-. --- -.
>
> > -.. . -- -. . -.. - --- .... . .-.. .-.. .-.-.-
> >
> > Note, if you translate the morse code to english, you may
> be
> > able to figure out why I didn't write the post in plain
> > english.
> >
> > > ***You are a cretin. I sincerely apologize for having
> to
> > > stoop to this level but it is quite apparent that you
> are
> > > sounding like a broken record. Worse still you are
> > > incapable of understanding the interpretations of the
> > FCC's
> > > rules by the FCC in Washington.
> > >
> > >
> > >
> > >
> > > > > ... 15.209 ... is an ancient rule that
> > > > > no longer seems to be enforced.
> > > >
> > > > > ... from what I have been told
> > > > > by people at the FCC and others ...
> > > >
> > > > > ... to my knowledge,...
> > > >
> > > > > I have not heard of one single instance ...
> > > >
> > > > etc.
> > > >
> > > > How much help would your statements be to someone who
> > was
> > > > cited by the FCC after operating according to your
> > > beliefs?
> > > > //
> > > >
> > >
> >
>

 

[dickfry]

>
> This scenario simply steers people to install and operate
> whatever they think they can get away with. And I have no
> problem with anyone (but me) wanting to do that. My only
> hope is that those other people really know what they are
> doing, and are willing to accept whatever consequences that
> might follow.
>

Okay, we get it. You're a rules Nazi. Seig heil, mein herr. Come on in a smash things up with your jackboots.

So exactly how are you helping us here. Creating dissention is somehow a useful way of improving our hobby for us?

We keep asking you nice to please go away, but you seem hell bent on coming in here and constantly causing trouble for no apparent reason other than some kind of ego gratification.

Yeah, you did a lot of stuff in broadcast engineering when you had a career. I used to be impressed. But you've lost it. Give it up and leave us alone. Your lording your impeccable credentials and your unassailable logic over us has worn very thin.

This isn't Gates Electronics. And they were destroyed by the same thing that made many of us get into Part 15 radio. The little guy has been wiped out by the big corporation.

You, sir are not part of the solution. You are part of the problem.


-The other Dick

 

[dickfry]

>
> Links to several separate FCC Notices about this were posted
> here yesterday.
>
> //
>

As I expected. You have no personal knowledge of this stuff, only what you read. Exactly the same as all the other Part 15 "knowledge" you keep spouting. You're like a priest who has been asked by a recently betrothed couple to explain the honeymoon.

The FCC charts are well and good for propagation using standard antennas, standard ground systems, power levels in the multiples of 1 kw and more important, distances over 10 km. There is absolutely no reason to believe that there is any validity to the methodology using milliwatt systems with widely divergent antennas and ground systems within a 1 or 2 km. To do so is pseudo-science.

I assume you know better than to try to foist this stuff off as having any validity for Part 15, so it is fair to question your motive in offering it as "science." The FCC AM propogation charts were never designed for Part 15 and their use in this manner should be highly suspect to anybody with technical training, as you claim to have.

But you would know there's something funny about applying these values to low power AM if you had ever bothered to involve yourself in the technology. Instead, we keep hearing from you about how they do it in commercial broadcasting.

I had the same pig-headed arrogance about FCC charts and my high power broadcast experience until I started experimenting with low power systems. It's a different world. But you can only know that by doing, not by inference.

Reading is great. Doing is better.


-Dick

 

[rfry]

> Only 10 ohms of ground loss in your model? Most of us Part
> 15 AM operators fervently *wish* our ground and coil losses
> were that low! As with any computer model, "garbage in,
> garbage out." -- JasonW
_____________

I know that, but using a low-loss model gives an upper limit for field strength from this ground-mounted antenna. Measured field strengths much greater than these will be a red flag to anyone wanting to avoid detection. That's why I used it.

If you (or anyone) wants to see the numbers with some higher ground loss, just send me the value you want to use, and I'll post them.

//

 

[rfry]

> The FCC charts are well and good for propagation using
> standard antennas, standard ground systems, power levels in
> the multiples of 1 kw and more important, distances over 10
> km. There is absolutely no reason to believe that there is
> any validity to the methodology using milliwatt systems with
> widely divergent antennas and ground systems within a 1 or 2
> km. To do so is pseudo-science.

The same physical laws apply to Part 15 AM as to commercial AM broadcasting. The equations allow entries for the differences in power and antenna height, as shown in dozens of antenna engineering textbooks. Read "Antennas for All Applications" by John Kraus, or Terman's "Radio Engineers Handbook" for examples.

The FCC charts even include instructions about how to use them for any power level.

//

 

[rfry]

> On the frequency I use (1600 kHz), there is always a
> constant "rushing" sound like that heard on a SW or CB radio
> tuned between stations, when my transmitter is off. When
> it's on, I get full quieting (if broadcasting carrier only)
> out to 1/4 mile on a pocket receiver.
_______________

Your experience then demonstrates that the FS meter you were using did not have the sensitivity needed for measuring relatively low field strengths such as those in Part 15 AM systems. But that doesn't mean that such fields cannot be measured, or that such meters do not exist. That is wrong in both cases.

//

 

[WCWalker]

***Still can't differentiate between fantasy and reality eh.? Move to western NY, because you will fit right in.

What the books say and what happens in real life are two distinctly different matters.


> > The FCC charts are well and good for propagation using
> > standard antennas, standard ground systems, power levels
> in
> > the multiples of 1 kw and more important, distances over
> 10
> > km. There is absolutely no reason to believe that there is
>
> > any validity to the methodology using milliwatt systems
> with
> > widely divergent antennas and ground systems within a 1 or
> 2
> > km. To do so is pseudo-science.
>
> The same physical laws apply to Part 15 AM as to commercial
> AM broadcasting. The equations allow entries for the
> differences in power and antenna height, as shown in dozens
> of antenna engineering textbooks. Read "Antennas for All
> Applications" by John Kraus, or Terman's "Radio Engineers
> Handbook" for examples.
>
> The FCC charts even include instructions about how to use
> them for any power level.
>
> //
>

 

[carlvanorden]

Lets cut to the chase...

> > On the frequency I use (1600 kHz), there is always a> > constant "rushing" sound like that heard on a SW or CB> radio> > tuned between stations, when my transmitter is off. When> > it's on, I get full quieting (if broadcasting carrier> only)> > out to 1/4 mile on a pocket receiver.> _______________> > Your experience then demonstrates that the FS meter you were> using did not have the sensitivity needed for measuring> relatively low field strengths such as those in Part 15 AM> systems. But that doesn't mean that such fields cannot be> measured, or that such meters do not exist. That is wrong> in both cases.> > //> Simply put Mr. Fry #1 wants everyone to use very expensive FS meters even if their part 15 signal interferes with no one>>>>>>>>>>>>>>>>>>>>Rules state that the FCC understands that that is not practicable (and that was printed out in this thread!).........................100 feet, 1,000, feet, or 2,000 feet, what is the matter with a signal that operates off a 100mW tx, with a 3 meter antenna that does not interfere with anyone else??????????????It is not even a question, it is a statement and this thread is getting rediculously long and involved when there is really no issue to discuss!!<P ID="signature">______________
[email protected], [email protected],[email protected]</P>

 

[rfry]

Re: Lets cut to the chase...

> ... what is the matter with a signal that
> operates off a 100mW tx, with a 3 meter antenna...
___________

Nothing, if that's really the case. But Physics says that a 3 meter antenna is not a 3 meter antenna when it, and the tx that drives it are installed at some elevation above ground level, and the tx chassis is connected by a long "ground wire" to physical earth. Then the effective radiator length is longer than 3 meters, and that longer radiator is more efficient.

Anyone can prove this by using the signal strength meter on a "ham" type communications receiver that tunes to the Part 15 frequency. An expensive FS meter isn't necessary.

In a fair test, the field strength indication you get on the ham receiver for the same receiving conditions (same propagation path, same receive antenna, same receiver settings, matched tx antenna, etc) will clearly show the field strength advantage of an elevated Part 15 transmit antenna system compared to one at ground level.

Please note that I don't care in the least about the configuration of the antennas that Part 15 AM users install and use, or how much field strength their systems produce. I have only attempted to inform Part 15 users of the provable technical performance of these configurations that, judging from what I read on these boards, they may not have recognized beforehand. They are free to use or reject this information as they see fit. But -- at least now they might know what they are really doing.

//

 

[radiopilot]

Re: Lets cut to the chase...

> > ... what is the matter with a signal that
> > operates off a 100mW tx, with a 3 meter antenna...
> ___________
>
> Nothing, if that's really the case. But Physics says that a
> 3 meter antenna is not a 3 meter antenna when it, and the tx
> that drives it are installed at some elevation above ground
> level, and the tx chassis is connected by a long "ground
> wire" to physical earth. Then the effective radiator length
> is longer than 3 meters, and that longer radiator is more
> efficient.
>
> Anyone can prove this by using the signal strength meter on
> a "ham" type communications receiver that tunes to the Part
> 15 frequency. An expensive FS meter isn't necessary.
>
> In a fair test, the field strength indication you get on the
> ham receiver for the same receiving conditions (same
> propagation path, same receive antenna, same receiver
> settings, matched tx antenna, etc) will clearly show the
> field strength advantage of an elevated Part 15 transmit
> antenna system compared to one at ground level.
>
> Please note that I don't care in the least about the
> configuration of the antennas that Part 15 AM users install
> and use, or how much field strength their systems produce.
> I have only attempted to inform Part 15 users of the
> provable technical performance of these configurations that,
> judging from what I read on these boards, they may not have
> recognized beforehand. They are free to use or reject this
> information as they see fit. But -- at least now they might
> know what they are really doing.
>
> //
>


Rfry,

Technically what you say about the ground wire being a radiator is very correct and no one here disputes that fact! This info is readily available anywhere, but the fact that the FCC does not specify the ground wire other that the 3 meter length for the antenna and ground lead, leaves room to interpret the rule in a grey area which the FCC agent in most cases will ignore except in cases we've read here regarding the Rangemaster ground lead.

I look at Rangemaster's website under the tips for getting 'more mileage' out of their transmitter, and it suggests using a mast/tower with a long ground lead 3-4 inches away and insulated from the tower, thereby doing exactly what you say about the ground lead being a radiator longer than the antenna itself, also they suggest over modulating the transmitter 130% if that'll give you extra range, but isn't 100% modulation the max the FCC indicates you can modulate? They also suggest that you use clotheslines as re-radiators, which to me may as well be the extra long antenna you suggest, even if it is not connected to the transmitter itself...

What I'm saying here is most of us have a transmitter at say 30' HAAT and the ground lead is attached to a metal pole which is grounded to the ground rod/radials which is what most stations commercial/amateur uses and I see nothing wrong with that and I'm sure the FCC agent should see nothing wrong with that as well.

The issue here is why all the hype over who is legal or not if it's plainly simple that no one here is trying to break any rules or laws and cause problems with the FCC?

Radiopilot

 

[JasonW]

Insanity is... (Re: Lets cut to the chase...)

I believe it was Albert Einstein who said that insanity is doing the same thing over and over again and expecting a different result. Arguing with rfry is in that category.

To Carl, Dick Fry, Keith Hamilton, RadioPilot, William, and everyone else here who has sparred with rfry: he's only here to be a troll and stir up trouble. You don't have to prove anything to him regarding the legality of our Part 15 equipment--the FCC has already approved it. He doesn't want Part 15 broadcasting to be legal at all, despite his claims to the contrary. Just ignore him.

While I disagree with Carl and RadioPilot regarding the legality of Part 15 transmitter kits, we can (and do) disagree without being disagreeable. Most importantly, my disagreement does not spring from a hatred of legal unlicensed broadcasting, but only from my knowlege of the Part 15 AM rules and my desire to be 100% legal without even a shadow of a doubt.

Let's get back to troll-free, sane, and productive Community Radio discussion, shall we? -- JasonW

 

[radio8z]

Well said Jason. Thanks

> I believe it was Albert Einstein who said that insanity is
> doing the same thing over and over again and expecting a
> different result. Arguing with rfry is in that category.
>
> To Carl, Dick Fry, Keith Hamilton, RadioPilot, William, and
> everyone else here who has sparred with rfry: he's only here
> to be a troll and stir up trouble. You don't have to prove
> anything to him regarding the legality of our Part 15
> equipment--the FCC has already approved it. He doesn't want
> Part 15 broadcasting to be legal at all, despite his claims
> to the contrary. Just ignore him.
>
> While I disagree with Carl and RadioPilot regarding the
> legality of Part 15 transmitter kits, we can (and do)
> disagree without being disagreeable. Most importantly, my
> disagreement does not spring from a hatred of legal
> unlicensed broadcasting, but only from my knowlege of the
> Part 15 AM rules and my desire to be 100% legal without even
> a shadow of a doubt.
>
> Let's get back to troll-free, sane, and productive Community
> Radio discussion, shall we? -- JasonW
>
Jason and others,

Well said! I have nothing to add.

Neil

 

[radiopilot]

Re: Insanity is... (Re: Lets cut to the chase...)

> I believe it was Albert Einstein who said that insanity is
> doing the same thing over and over again and expecting a
> different result. Arguing with rfry is in that category.
>
> To Carl, Dick Fry, Keith Hamilton, RadioPilot, William, and
> everyone else here who has sparred with rfry: he's only here
> to be a troll and stir up trouble. You don't have to prove
> anything to him regarding the legality of our Part 15
> equipment--the FCC has already approved it. He doesn't want
> Part 15 broadcasting to be legal at all, despite his claims
> to the contrary. Just ignore him.
>
> While I disagree with Carl and RadioPilot regarding the
> legality of Part 15 transmitter kits, we can (and do)
> disagree without being disagreeable. Most importantly, my
> disagreement does not spring from a hatred of legal
> unlicensed broadcasting, but only from my knowlege of the
> Part 15 AM rules and my desire to be 100% legal without even
> a shadow of a doubt.
>
> Let's get back to troll-free, sane, and productive Community
> Radio discussion, shall we? -- JasonW
>

JasonW,

You couldn't have said it better! Although I disagree without being diagreeable about the kits issue, but hey... let's all broadcast a clean, safe and legal signal, this is all anyone here can wish.

Let's all put this issue to rest if it's OK with Mr. Fry.. what do you say we put the hatchets away and be adults about this?

Mr. Fry... with the knowledge you posess, you have the ability to make long, very long lasting friends here if only you step into our realm of things here and help those that require the technical issues of getting the most transmission of this tiny 100mw signal!

Radiopilot

 

[JasonW]

Re: Insanity is... (Re: Lets cut to the chase...)

> You couldn't have said it better! Although I disagree
> without being diagreeable about the kits issue, but hey...
> let's all broadcast a clean, safe and legal signal, this is
> all anyone here can wish.

Agreed!

> Mr. Fry... with the knowledge you posess, you have the
> ability to make long, very long lasting friends here if only
> you step into our realm of things here and help those that
> require the technical issues of getting the most
> transmission of this tiny 100mw signal!

The antidote to this is experience with the equipment. More than one skeptical broadcast engineer has tried Part 15 AM and discovered that, as Florida's state motto says, "The rules are different here." Unlike full-power broadcast AM, with Part 15 AM equipment the high frequencies propagate farther than low ones (due to our electrically tiny 3 meter antennas being more efficient [actually, less inefficient!] at higher frequencies), and antenna height *does* significantly affect Part 15 AM range, unlike full-power AM stations with full-size towers. What has surprised them most is that these "peanut whistle" transmitters can legally reach significant numbers of listeners with clean, clear signals. -- JasonW

 

[KeithHamilton]

Re: Well said Jason. Thanks

I agree too, I have spent time privatly Emailing with Fry, I am busy so I had to put an end to it.