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

This video highlights the HobbyBroadcaster.net lab review of the i A.M. Radio Part 15 certified AM transmitter manufactured by Radio Systems, Inc. of Logan Township, New Jersey. This is the newly improved version of the transmitter formerly marketed as the Talking House transmitter by Broadcast Marketing LLC. This companion video review accompanies the written review located at HobbyBroadcaster.net

Category:

Science & Technology

Tags:

• Part 15 AM
• part 15 radio
• part 15 broadcasting
• Part 15 Transmitter
• low power AM
• LPAM
• am transmitter
• low power fm transmitter
• talking house transmitter
• AM Radio Station
• fm radio station
• am broadcasting
• am broadcast transmitter
• talking house

[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]

@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.

[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 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.

[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.

[vwestlife]

Does the new model include NRSC pre-emphasis? All commercially licensed AM broadcasters use pre-emphasis to improve the treble response of an average AM radio. A transmitter not using pre-emphasis will sound rather dull on most radios.

[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]

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.

[kieranmullen2]

Talking house before they were purchased made model 5.0 at least. Your test should have compared that 5.0 Talking House version against the I AM Radio version with improvements.