Rare AM part 15 NOUO (Michigan 2014)

This is a strange coincidence: On July 31 a post was made about Hamtramck on a different forum linking to an article. Then Hamtramck gets a NOUO in October. I wonder if the added publicity was a bad thing.

Publicity is indeed a bad thing if you're running outside of the Part 15 rules.  If you are legal, you have nothing to fear, and publicity can be a very good thing - if you want listeners other than your family, that is.

A glaring omission in all the documentation linked to (including their website) is details of the the station's installation.  Using a Hamilton Rangemaster transmitter is only one (small) part of the entire equation to broadcasting legally under Part 15 rules.

There is another similar story... about Ken Cartright and his now famous KENC in Somewhere, Oregon, who got splashy news coverage because he broadcast his wedding live on his part 15 station, soon to be trashed by an agent and run off the air.

Same agent marauded Jerry Gaule following some stands-out-on-the-page publicity in the paper.

There might be some agents who enjoy the hunt and kill.

"The field strength of the signal on
frequency 1610 kHz was measured at 30,000 microvolts per meter (uV/m) at
40.7 meters"

Very interesting f/s reading. even for an elevated installation he had a reading of 30mV/m (30000uV/m) @ 40.7 m. his input had to be well above 100mW to generate that kind of field strength on 1610 even with an elevated install. that install appears to only be at most 20ft-30ft above the ground.

maybe rich can come in and give us some calculations. say his install has a 102" radiator with a 30ft ground lead on 1610 khz and produced a radiated field of 30000uV/m @ 40.7m. what would his ERP be and likely input power be? i'm betting it is well above 100mW input.

I am not sure that even at 400 mW you could squeeze that F/S from a Rangemaster.  Could be a Typo.  It has happened before. I hope he finds a way to stay on the air.  He has a very nice setup and probably not bothering anyone, especially on 1610.

Given such an implausible NOUO there could certainly have been a typo... giving the benefit of the doubt.

But if we start backing away from "benefit of the doubt" we consider... incorrect use of FIM (Field Intensity Meter) by an inspector. It could happen.

If we cancel all benefit of doubt and wonder if a malevolent inspector is outright lying it would seem in character with the government in general.

Inspecting the inspection is our right.

Or it could be that he's bending the rules. Most likely that, in fact. Giving legit Part 15 broadcasters a bad name in the process.

Why is it so difficult to stay at 100mw with a ground mounted install?

Deleted.

I deleted the earlier post of this subject because I wanted to add to it, then ran out of time.

While it seems that most readers of Part 15 boards are very skeptical about the accuracy of antenna modeling software, the following is offered for any who may be interested.

A 1610 kHz transmit system was modeled in NEC4.2, based on the following assumptions...

• Transmitter with 102" whip attached
• Base of transmitter elevated 40 feet above level earth
• A vertical, linear, metallic path from the base of the transmitter chassis to an 8' x 1/2" OD  "ground rod" buried vertically in 8 mS/m, d.c. 13 earth
• RF resistance of transmitter loading coil at system resonance = 15 ohms
• System installed in an open area having no re-radiating conductors within a radius of several wavelengths from the transmit system

The amount of r-f carrier power needed at the input to the loading coil to produce a groundwave field intensity of 30,000 µV/m for a path length of 40.7 meters along 8 mS/m d.c. 13 earth is 165 mW.

It is unknown how closely this NEC analysis agrees with any given physical installation, or the power output capability of any particular transmitter (FCC-certified, or not).

Bending the rules?  How so? Do you have direct personal knowledge? This transmitter will not put out excessive power without serious degradation of the audio.  Considering the amount of audio/studio equipment this guys has, it is doubtful the transmitter would be operated in that fashion. Un-qualified opinon from me..

From your observations Rich the point is, had the ground lead not been so long, the field strength would have been moot.

True for a total radiating length of 3 meters, but using a transmitter having more than 100 mW of d-c input power still might  come to FCC attention.

Member Rich said: "While it seems that most readers of Part 15 boards are very skeptical about the accuracy of antenna modeling software... "

To get it out of the way I must first say that I don't believe the label "readers of Part 15 boards" is meant to be condescending. Many are proud of being such readers, and are very devout about low power living.

Whether any are skeptical or possibly dubious about antenna modeling software seems to arise from a sense that actual real-life experience sometimes seems to vary from predictions produced by modeling software, and as long as this attitude is held, whole hearted trust in modeling software will remain withheld.

However I would insist that software antenna modelings remain a welcome contribution to the overall business of prediction and experience, so that by the end of the day we end up with something.

With that in mind I propose an expression of gratitude for Member Fry for bringing software modelings to the discussion.