Babysitting Your Tracker
A frequent topic of discussion in APRS-related circles is:
"Must a control operator babysit a tracker, or may it be sent off into the cruel world on its own?"
The short answer per FCC rules is:
No, it does not have to be babysat and may be operated even where a control operator cannot immediately lay hands on the unit.
A careful reading of the rules (along with some understanding of how the rules are applied to different situations) will reveal the answer. While it is not as straightforward as one would think, it is not difficult to determine the correct answer for a given set of circumstances.
While we always advocate for individuals to read the rules and make up their own mind about what the FCC requires as it's your license on the line, we hope the contents of this wiki article will help guide you in your decision.
The first and most important indicator is that unattended trackers have been around for a dozen years. Every day hundreds if not thousands of these devices transmit. The FCC is very aware of their existence, yet not a single action has been taken by the FCC against unattended trackers.
A more detailed answer:
People who are not familiar with the FCC rules tend to think that you need a licensed amateur to physically be with the APRS tracker. This is not always the case. In fact, it is rarely the case. The correct answer depends upon how the station is set up. But first, some underlying regulations:
- It is well accepted that a completely unattended tracker or digipeater is within the rules. CFR 47.97.221(b)
- Amateurs must prevent unlicensed operation. CFR 47.97.5 , 7 and 115 generally. That is the crux of the argument about “unattended” operation. Digital stations can be automatically controlled. CFR 47.97.221 The key to all this is control of the station. If the control operator can prevent ‘non-control operators’ including unlicensed individuals from ‘controlling’ the tracker, the tracker is well within the rules. See above.
If the person(s) accompanying the tracker cannot change any parameter of the transmitter other than power on/off, then they cannot ‘control’ the unit and you are within the FCC rules. Enclosing the transmitter or transceiver inside another box so that no controls were available, or "locking" the radio so that nobody can mess with the settings, should steer you clear of possible violations. Unsure about that power on/off switch thing? Look up the "N1547C tracker" thread on APRSSIG and see below.
If the person can change the power level, modulation method, frequency, or grab a microphone and "play around", then you'd be in violation of the rules if that person exercised any of that control. Ultimately, it is better to ‘box it up’ to protect your license and to make sure that the unit stays configured as it was when it left your hands.
- The regulations do require a control operator (and station licensee) to cease operations if they are notified by a proper authority of their transmission causing harmful interference. CFR 47.97.109 (d) Being told to ‘cease transmission’ is not the same as having to be able to do so instantly, and a call on the radio, etc. to shut the unit off, along with a time-out timer or watchdog circuit on the transmitter will more than satisfy that requirement.
A control operator must be able to exercise that control over the device, but there is nothing in the rules that specifies the time lag allowed to exercise that control or how to exercise that control. The control operator can direct an unlicensed person who has physical access to the tracker to turn the device ON or OFF. This command from the control operator to an unlicensed person may be done over telephone, cell-phone, megaphone, FRS, GMRS, CB, or what-have-you.
- HF trackers are a somewhat special case. In order to be covered under section 221(b) and be automatically controlled, they must operate only in the following portions of the respective bands: the 28.120-28.189 MHz, 24.925-24.930 MHz, 21.090-21.100 MHz, 18.105- 18.110 MHz, 14.0950-14.0995 MHz, 14.1005-14.112 MHz, 10.140-10.150 MHz, 7.100-7.105 MHz, or 3.585-3.600 MHz segments.
Please see the thread titled "Re: Newbie Questions, is Ham license required?" from the TinyTrak list that occurred on October 9th, 2007. One could also peruse the APRSSIG mailing list and find threads at least twice a year that cover this unattended tracker issue.
Some important references:
A quote by Riley Hollingsworth, FCC Special Counsel in the Spectrum Enforcement Division. He's the FCC guy you'd have to answer to if you did something wrong: http://www.arrl.org/news/stories/2007/06/01/100/?nc=1
The FCC defines "automatic control" in CFR 47.97.3(a)(6) as: "The use of devices and procedures for control of a station when it is transmitting so that compliance with the FCC Rules is achieved without the control operator being present at a control point."
Another good discussion on the matter: http://lists.tapr.org/pipermail/aprssig/2004-November/001620.html
Examine the FCC rules for yourself, in particular pay attention to sections about "automatic control", "beacons", "control operator", and "control point". For your convenience, here's a link to the rules: http://www.arrl.org/FandES/field/regulations/news/part97/
In addition to looking at the definitions contained in part 97.3, be sure to look at 97.221 (automatic operation) and the sections covering station licenses (97.5), control operators (97.7) and control operator duties (97.105). In reality, you should take the time to look through all the rules since all amateurs are responsible for operating properly under the rules.
A quote from an official observer in 1996:
From: Mike Musick To: <firstname.lastname@example.org> Subject: Re: Question on beacons Steve writes: > I note that people are using beacons which transmit from an > unattended situation. Do the FCC regulations now allow one > to transmit in this manner, without a station operator present > nor a supervisory remote control link? Yes, and the answer is: 97.221 Automatically controlled digital station. (b) A station may be automatically controlled while transmitting a RTTY or data emission on the 6m or shorter wavelength bands, and on... [numerous HF segments]. and: 97.109 Station control. (d) When a station is being automatically controlled, the control operator need not be at the control point. ...[qualified station types, which includes the above] So we're covered. ...mike/N0QBF (Official Observer)
Don't ask the FCC!
The title seems humorous on the surface, but it's probably accurate. The article suggests asking such questions of Dan Henderson at ARRL instead of the FCC and explains why: http://groups.yahoo.com/group/TinyTrak/message/15643