i A.M. Radio Part 15 Certified AM Transmitter Review (formerly known as Talking House)

[HobbyBroadcaster]

@vwestlife It is believed that neither this or the other AM transmitters we have previously reviewed contain on-board NRSC pre-emphasis and brick-wall protection. Our lab testing includes the use of receivers manufactured both prior to and after implementation of the NRSC-1 standard for AM broadcasting. While not ideal, end users of these transmitters can use equalization or an audio processor with NRSC pre-emphasis and brick-wall bandwidth protection as a workaround.

[HobbyBroadcaster]

@MichaelJGrant I visited the Radio Systems facility back in 2009 where I learned both the transmitter and remote antenna tuner as a certified "system." I don't want to inadvertently disclose any "trade secrets" in regards to the unit but I would assume certification with the remote antenna tuner may be considered the final stage of the system.

The transmitter achieves a ground through the supplied wall wart power adapter which is has a three pin plug.

[HobbyBroadcaster]

There was little differences between the TH4.3 and 5.0 as far as audio. I had the pleasure of a tour of the Radio Systems factory on October 22 as well as discussing the Talking House / i A.M. Radio transmitter line with company officials. From an audio fidelity standpoint the 5.0 version of Talking House is the same as the 4.3 used in our bench tests. The audio improvements were implemented as part of the i A..M. Radio.transmitter version 5.0 developed at Radio Systems.

[HobbyBroadcaster]

@MichaelJGrant The FCC label in located on the bottom of the transmitter itself. I do recall when Radio Systems took over the Talking House line that when they went through the transferred documentation that the certification indeed covered the system when the remote tuner is paired together with the transmitter as this was a past topic in the HobbyBroadcaster net forums.

[Trance]

I actually bought the older model from a goodwill a couple years ago. I wish I had the newer model! The older model has a built in wire antenna that really doesn't transmit very far.

[MichaelJGrant]

@HobbyBroadcaster When I saw the meter on the remote antenna/tuning unit, my guess, too, was that the ATU was not passive, but rather where the final RF stage phantom powered ala home sat dish method via the coax cable. That's more a legalistic fig leaf than a trade secret in my opinion. If the ground lead is the power supply return, wouldn't that have to be included in the 3m? Also, I didn't see the required FCC ID label.

[HobbyBroadcaster]

@MichaelJGrant I really can't comment as I'm neither the manufacturer nor the certification facility for this transmitter. I can tell you that the transmitter and ATU were certified as a system, so I would assume the FCC knew what they were doing when they accepted the certification of the transmitter system. I do believe there is some suppression on the ground lead internal to the unit which may have been considered during the unit's certification but this just an assumption on my part.

[frostproofnet]

... If you don't want to operate under 15.219, then you can run under the general provisions of Section 15.209. This means your Part 15 AM setup must have a field strength not over (24000/f) uV/m at 30 meters, where f is your operating frequency in kHz. which means simply an effective transmitting range of 200-300 ft.

[MichaelJGrant]

This is a mighty impressive unit that must have cost a small fortune to develop. However, Part 15.219 doesn't simply limit the antenna to 3m, but the *combined* length of the antenna, transmission line, and ground lead to 3m. I don't know how a remote antenna unit and 100 ft. of coax meets that requirement. I see there is a local antenna terminal on the back. Where does it get a ground? The line cord?

[HobbyBroadcaster]

Please see the video's description above for when to order a transmitter or ATU.

[kargocult]

The external antenna tuning unit would seem to be a violation of FCC rules, which say 3 meter antenna including ground wire
and any feedline.

[cancelaaatoday]

Okay, you all are talking WAAYYY over my head! LOL! All I want to know is, HOW can I use/utilize something like this to advertise my business while still being mobile? I had a friend telling me about this some years ago but I never followed up and I'm now just seeing the huge potential! He said something about how you can have a *looping* repeating commercial or something and have something on your car/truck trunk or back door instructing those behind you where to tune in to hear! is this true?

[RobertC]

Is there any way to disable the AGC? i am going to be using an audio source with multiband and AGC already turned on.

[FrancisLitanofficialJAPINOY]

If I use that AM transmitter in French Overseas countries in the Americas like St. Pierre et Miquelon (North America near Canada), French Guiana (South America, and Saint Martin (Caribbean).

Some cars in French overseas territories in the Americas are imported from France and the car radio on AM are 9 kHz increments.

I'll tune this transmitter on 660 kHz and I'll tune the 9K AM digital tunning receiver on 657 kHz, it 3 kHz off as it tuned perfectly.

This transmitter built for the Americas via ITU Region 2 on 10K interval.

thank you.

[frostproofnet]

It's illlegal to broadcast part 15 am with an antenna that exceeds 10 ft Total length of antenna, transmission line, and ground lead not over 3 meters ... this would require the optional turner unit and whip antenna not to exceed the above rule... even though the transmitter is legal the tuner unit with coax plus whip is not and you should state this fact.