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From: Nate Waddoups
To: Steve Kaluf
Subject: FCC rules concerning RC system components

Mr. Kaluf,

I recently read the AMA's interpretation of the FCC rules pertaining to transmitters and frequency modules, and I must respectfully disagree. I believe that the confusion comes from our community's (mis)use of the term "transmitter." For historical reasons, we continue to describe devices like the Futaba 8U and 9Z as "transmitters" but technically speaking that is not what they are. Reading the FCC regulations with this obsolete terminology in mind will inevitably lead to confusion. Reading the FCC regulations with more appropriate terminology in mind leaves no room for confusion.

The 8U and 9Z devices are encoders, which convert gimbal and switch positions into low-frequency logic-level (*not* radio) signals. The little black box we commonly refer to as a "frequency module" is actually the transmitter, a fact which the FCC recognizes when the approve them under Part 95. The following URL will show you the FCC's authorization of the AZPFP-TK-FM-72A "Licensed Non-Broadcast Station Transmitter," which we modelers commonly call a "Futaba 9Z frequency module."

http://gullfoss2.fcc.gov/cgi-bin/ws.exe/prod/oet/forms/misc/Grant_Form.hts?application_id=20150&mode=COPY&fcc_id=AZPFP- TK-FM-72A

There are no records of FCC approval of the 8U or 9Z devices. The device we commonly call a transmitter only receives FCC approval when it actually contains the circuitry that generates the radio signals, as in the case of the lower-end radios that do not use what we commonly call "frequency modules." Thus, by the AMA's present interpretation of the rules, all 8U and 9Z users are criminals, because they are using "transmitters" not approved by the FCC. Clearly this is not the case, and the present situation is perfectly reasonable if one accepts the fact that the 8U and 9Z are more properly called "encoders" than "transmitters."

Only one of the following can be true:

a) The little box we commonly refer to as a frequency module is technically a transmitter, and users of the Futaba 8U and 9Z encoders are acting lawfully, because the FCC has approved of the FP-TP-FM and FP-TK-FM transmitters used by the 8U and 9Z encoders.

b) The big box we commonly refer to as a transmitter is just that, and users of the Futaba 8U and 9Z systems are acting criminally because they are using transmitters which have not been approved by the FCC.

I think it's quite clear that (a) is correct and (b) is mistaken. The URL above will show you the FCC approval for the transmitters used with the 8U and 9Z encoders.

Of course, I shall respectfully concede my position and accept the AMA's current interpretation when I see FCC documentation that demonstrates their acceptance of the 8U and 9Z devices as transmitters.

Note that I limited the above to the Futaba 8U and 9Z encoders and FP-TP/FP-TK transmitters only because I am most familiar with them. Similar distinctions can be made with equipment from the other major manufacturers as well, for example the JR 8103 encoder has no FCC approval, but the transmitter commonly used with the 8103 bears FCC ID BRWNET72FP, as you can see at the following URLs:

http://www.horizonhobby.com/Description.asp?prod=JRPTXM**&ThisPage=Radios&Category=P&item=RPX&refer=
http://gullfoss2.fcc.gov/cgi-bin/ws.exe/prod/oet/forms/misc/Grant_Form.hts?application_id=32619&mode=COPY&fcc_id=BRWNET72FP

Thank you for your time and consideration,

Nate Waddoups
Redmond WA USA

CC: rec.models.rc.air, http://www.natew.com