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  Repeater and Auxiliary
Station Control

Compiled by Robert W. Meister WA1MIK
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Back in the good old days, repeaters were considered their own stations. They had their own call signs and licenses, often having a "WR" prefix to the region number. There were control operators who could shut down the repeater if he/she heard a user or equipment malfunction. They used either wire line (phone line) control (you could even get a copper pair that would transfer DC current or voltage from the control point(s) to the repeater) or a second receiver on a control frequency above 220 MHz. FCC Rules and Regulations Part §97.88 (technically 47 C.F.R. 97) specified a few things about what would eventually become repeater control.

The 1989 rules were transcribed from the "Latest Version" of the ARRL's FCC Rule Book, 8th edition, which covered the May 11, 1989 revisions to Part 97. This revision gave us a code-less Technician license class, expansion of the novice operating privileges, loss of part of the 220 MHz band, and other small changes. All the other rules were extracted from Government Printing Office (GPO) PDF documents that are available on-line.

§97.88 Remote Control:

§97.88 Operation of a Station by Remote Control.
An amateur radio station may be operated by remote control only if there is compliance with the following:
  (a) A photocopy of the remotely controlled station license shall be
    1) posted in a conspicuous place at the remotely controlled transmitting location, and
    2) placed in the log of each authorized control operator.
  (b) The name, address and telephone number of the remotely controlled station licensee and at least one control operator shall be posted in a conspicuous place at the remotely controlled transmitter location.
  (c) Except for operation under automatic control, a control operator shall be on duty when the station is being remotely controlled. Immediately before and during the periods the remotely controlled station is in operation, the frequencies used for emission by the remotely controlled station shall be monitored by the control operator. The control operator shall terminate all transmissions upon any deviation from the rules.
  (d) Provisions must be incorporated to limit transmission to a period of no more than 3 minutes in the event of malfunction in the control link.
  (e) A station in repeater operation shall be operated by radio remote control only when the control link uses frequencies other than the input (receiving) frequencies of the station in repeater operation.

The first few sub-sections mainly pertain to stations operated as remote bases; the latter sub-sections pertain to repeaters. Most people interpreted this to mean that you could not control a repeater by signals used on the input frequency. The FCC attempted to clean up and simplify the rules in 1989 when it gave half of the 220 MHz amateur band to UPS (who ended up not using it after all), added the no-code technician license, deleted §97.88 entirely and no longer required repeaters to have separate licenses. This date brought about a major revision to the almost the entire Part 97 rules. §97.201 deals with auxiliary stations and §97.205 handles repeater stations, and they're very similar, rule-wise.

§97.201 Auxiliary Stations (remote bases, control stations, etc):

§97.201 Auxiliary station. (1989)
  (a) Any amateur station licensed to a holder of a Technician, General, Advanced or Amateur Extra Class operator license may be an auxiliary station. A holder of a Technician, General, Advanced or Amateur Extra Class operator license may be the control operator of an auxiliary station, subject to the privileges of the class of operator license held.
  (b) An auxiliary station may transmit only on the 1.25 m and shorter wavelength bands, except the 220.0-220.5 MHz, 431-433 MHz, and 435-438 MHz segments.
  (c) Where an auxiliary station causes harmful interference to another auxiliary station, the licensees are equally and fully responsible for resolving the interference unless one station's operation is recommended by a frequency coordinator and the other station's is not. In that case, the licensee of the non-coordinated auxiliary station has primary responsibility to resolve the interference.
  (d) An auxiliary station may be automatically controlled only when it is part of a system that includes a repeater station also being automatically controlled.
  (e) An auxiliary station may transmit one-way communications.

§97.201 Auxiliary station. (2004)
  (a) Any amateur station licensed to a holder of a Technician, Technician Plus, General, Advanced or Amateur Extra Class operator license may be an auxiliary station. A holder of a Technician, Technician Plus, General, Advanced or Amateur Extra Class operator license may be the control operator of an auxiliary station, subject to the privileges of the class of operator license held.
  (b) An auxiliary station may transmit only on the 1.25 m and shorter wavelength bands, except the 219-220 MHz, 222.000-222.150 MHz, 431-433 MHz, and 435-438 MHz segments.
  (c) Where an auxiliary station causes harmful interference to another auxiliary station, the licensees are equally and fully responsible for resolving the interference unless one station's operation is recommended by a frequency coordinator and the other station's is not. In that case, the licensee of the non-coordinated auxiliary station has primary responsibility to resolve the interference.
  (d) An auxiliary station may be automatically controlled.
  (e) An auxiliary station may transmit one-way communications.

In 2006, §97.201(b) got replaced with this, essentially adding the 2 m band to the list of acceptable transmit frequencies. The rule is otherwise unchanged.

  (b) An auxiliary station may transmit only on the 2 m and shorter wavelength bands, except the 144.0-144.5 MHz, 145.8-146.0 MHz, 219-220 MHz, 222.00-222.15 MHz, 431-433 MHz, and 435-438 MHz segments.

So this brings us to the current (May 2011) versions of these two parts, which are essentially unchanged from the 2007 version.

§97.201 Auxiliary station. (2011)
  (a) Any amateur station licensed to a holder of a Technician, General, Advanced or Amateur Extra Class operator license may be an auxiliary station. A holder of a Technician, General, Advanced or Amateur Extra Class operator license may be the control operator of an auxiliary station, subject to the privileges of the class of operator license held.
  (b) An auxiliary station may transmit only on the 2 m and shorter wavelength bands, except the 144.0-144.5 MHz, 145.8-146.0 MHz, 219-220 MHz, 222.00-222.15 MHz, 431-433 MHz, and 435-438 MHz segments.
  (c) Where an auxiliary station causes harmful interference to another auxiliary station, the licensees are equally and fully responsible for resolving the interference unless one station's operation is recommended by a frequency coordinator and the other station's is not. In that case, the licensee of the non-coordinated auxiliary station has primary responsibility to resolve the interference.
  (d) An auxiliary station may be automatically controlled.
  (e) An auxiliary station may transmit one-way communications.

§97.205 Repeater Stations (automatic repeaters):

§97.205 Repeater station. (1989)
  (a) Any amateur station licensed to a holder of a Technician, General, Advanced or Amateur Extra Class operator license may be a repeater. A holder of a Technician, General, Advanced or Amateur Extra Class operator license may be the control operator of a repeater, subject to the privileges of the class of operator license held.
  (b) A repeater may receive and retransmit only on the 10 m and shorter wavelength frequency bands except the 28.0-29.5 MHz, 50.0-52.0 MHz, 144.0-144.5 MHz, 145.5-146.0 MHz, 220-220.5 MHz, 432.0-433.0 MHz, and 435.0-438.0 MHz segments.
  (c) Where the transmissions of a repeater cause harmful interference to another repeater, the two station licensees are equally and fully responsible for resolving the interference unless the operation of one station is recommended by a frequency coordinator and the operation of the other station is not. In that case, the licensee of the non-coordinated repeater has primary responsibility to resolve the interference.
  (d) A repeater may be automatically controlled.
  (e) Ancillary functions of a repeater that are available to users on the input channel are not considered remotely controlled functions of the station. Limiting the use of a repeater to only certain user stations is permissible.
  (f) Before establishing a repeater in the National Radio Quiet Zone or before changing the transmitting frequency, transmitter power, antenna height or directivity, or the location of an existing repeater, the station licensee must give written notification thereof to the Interference Office, National Radio Astronomy Observatory, P.O. Box 2, Green Bank, WV 24944.
    1) The notification must include the geographical coordinates of the station antenna, antenna ground elevation above mean sea level (AMSL), antenna center of radiation above ground level (AGL), antenna directivity, proposed frequency, type of emission, and transmitter power.
    2) If an objection to the proposed operation is received by the FCC from the National Radio Astronomy Observatory at Green Bank, Pocahontas County, WV, for itself or on behalf of the Naval Research Laboratory at Sugar Grove, Pendleton County, WV, within 20 days from the date of notification, the FCC will consider all appeals of the problem and take whatever action is deemed appropriate.

So this rule legalized closed/private repeaters and allowed for things like tone access and other member coding schemes. It is not clear if primary on/off control is considered an ancillary function. Many people thought this prohibited control via the input of the repeater.

Sub-section (f) was deleted and replaced with sub-section (h), and sub-section (g) was added to relieve station control operators (and apparently the licensee of the repeater station) from legal action on behalf of repeater users. The Arecibo Observatory in Puerto Rico now becomes a sensitive area.

§97.205 Repeater station. (2004)
  (a) Any amateur station licensed to a holder of a Technician, General, Advanced or Amateur Extra Class operator license may be a repeater. A holder of a Technician, General, Advanced or Amateur Extra Class operator license may be the control operator of a repeater, subject to the privileges of the class of operator license held.
  (b) A repeater may receive and retransmit only on the 10 m and shorter wavelength frequency bands except the 28.0-29.5 MHz, 50.0-51.0 MHz, 144.0-144.5 MHz, 145.5-146.0 MHz, 222.00-222.15 MHz, 431.0-433.0 MHz, and 435.0-438.0 MHz segments.
  (c) Where the transmissions of a repeater cause harmful interference to another repeater, the two station licensees are equally and fully responsible for resolving the interference unless the operation of one station is recommended by a frequency coordinator and the operation of the other station is not. In that case, the licensee of the non-coordinated repeater has primary responsibility to resolve the interference.
  (d) A repeater may be automatically controlled.
  (e) Ancillary functions of a repeater that are available to users on the input channel are not considered remotely controlled functions of the station. Limiting the use of a repeater to only certain user stations is permissible.
  (f) [Reserved]
  (g) The control operator of a repeater that retransmits inadvertently communications that violate the rules in this part is not accountable for the violative communications.
  (h) The provisions of this paragraph do not apply to repeaters that transmit on the 1.2 cm or shorter wavelength bands. Before establishing a repeater within 16 km (10 miles) of the Arecibo Observatory or before changing the transmitting frequency, transmitter power, antenna height or directivity of an existing repeater, the station licensee must give notification thereof at least 20 days in advance of planned operation to the Interference Office, Arecibo Observatory, Post Office Box 995, Arecibo, Puerto Rico 00613, in writing or electronically, of the technical parameters of the proposal. Licensees who choose to transmit information electronically should e-mail to: prcz@naic.edu.
    1) The notification shall state the geographical coordinates of the antenna (NAD–83 datum), antenna height above mean sea level (AMSL), antenna center of radiation above ground level (AGL), antenna directivity and gain, proposed frequency and FCC Rule Part, type of emission, effective radiated power, and whether the proposed use is itinerant. Licensees may wish to consult interference guidelines provided by Cornell University.
    2) If an objection to the proposed operation is received by the FCC from the Arecibo Observatory, Arecibo, Puerto Rico, within 20 days from the date of notification, the FCC will consider all aspects of the problem and take whatever action is deemed appropriate. The licensee will be required to make reasonable efforts in order to resolve or mitigate any potential interference problem with the Arecibo Observatory.

The 2007 version of §97.205 now includes more details for contacting the Arecibo Observatory.

§97.205 Repeater station. (2007)
  (a) Any amateur station licensed to a holder of a Technician, General, Advanced or Amateur Extra Class operator license may be a repeater. A holder of a Technician, General, Advanced or Amateur Extra Class operator license may be the control operator of a repeater, subject to the privileges of the class of operator license held.
  (b) A repeater may receive and retransmit only on the 10 m and shorter wavelength frequency bands except the 28.0-29.5 MHz, 50.0-51.0 MHz, 144.0-144.5 MHz, 145.5-146.0 MHz, 222.00-222.15 MHz, 431.0-433.0 MHz, and 435.0-438.0 MHz segments.
  (c) Where the transmissions of a repeater cause harmful interference to another repeater, the two station licensees are equally and fully responsible for resolving the interference unless the operation of one station is recommended by a frequency coordinator and the operation of the other station is not. In that case, the licensee of the non-coordinated repeater has primary responsibility to resolve the interference.
  (d) A repeater may be automatically controlled.
  (e) Ancillary functions of a repeater that are available to users on the input channel are not considered remotely controlled functions of the station. Limiting the use of a repeater to only certain user stations is permissible.
  (f) [Reserved]
  (g) The control operator of a repeater that retransmits inadvertently communications that violate the rules in this part is not accountable for the violative communications.
  (h) The provisions of this paragraph do not apply to repeaters that transmit on the 1.2 cm or shorter wavelength bands. Before establishing a repeater within 16 km (10 miles) of the Arecibo Observatory or before changing the transmitting frequency, transmitter power, antenna height or directivity of an existing repeater, the station licensee must give written notification thereof to the Interference Office, Arecibo Observatory, HC3 Box 53995, Arecibo, Puerto Rico 00612, in writing or electronically, of the technical parameters of the proposal. Licensees who choose to transmit information electronically should e-mail to: prcz@naic.edu.
    1) The notification shall state the geographical coordinates of the antenna (NAD–83 datum), antenna height above mean sea level (AMSL), antenna center of radiation above ground level (AGL), antenna directivity and gain, proposed frequency and FCC Rule Part, type of emission, effective radiated power, and whether the proposed use is itinerant. Licensees may wish to consult interference guidelines provided by Cornell University.
    2) If an objection to the proposed operation is received by the FCC from the Arecibo Observatory, Arecibo, Puerto Rico, within 20 days from the date of notification, the FCC will consider all aspects of the problem and take whatever action is deemed appropriate. The licensee will be required to make reasonable efforts in order to resolve or mitigate any potential interference problem with the Arecibo Observatory.

§97.205 Repeater station. (2011)
  (a) Any amateur station licensed to a holder of a Technician, General, Advanced or Amateur Extra Class operator license may be a repeater. A holder of a Technician, General, Advanced or Amateur Extra Class operator license may be the control operator of a repeater, subject to the privileges of the class of operator license held.
  (b) A repeater may receive and retransmit only on the 10 m and shorter wavelength frequency bands except the 28.0-29.5 MHz, 50.0-51.0 MHz, 144.0-144.5 MHz, 145.5-146.0 MHz, 222.00-222.15 MHz, 431.0-433.0 MHz, and 435.0-438.0 MHz segments.
  (c) Where the transmissions of a repeater cause harmful interference to another repeater, the two station licensees are equally and fully responsible for resolving the interference unless the operation of one station is recommended by a frequency coordinator and the operation of the other station is not. In that case, the licensee of the non-coordinated repeater has primary responsibility to resolve the interference.
  (d) A repeater may be automatically controlled.
  (e) Ancillary functions of a repeater that are available to users on the input channel are not considered remotely controlled functions of the station. Limiting the use of a repeater to only certain user stations is permissible.
  (f) [Reserved]
  (g) The control operator of a repeater that retransmits inadvertently communications that violate the rules in this part is not accountable for the violative communications.
  (h) The provisions of this paragraph do not apply to repeaters that transmit on the 1.2 cm or shorter wavelength bands. Before establishing a repeater within 16 km (10 miles) of the Arecibo Observatory or before changing the transmitting frequency, transmitter power, antenna height or directivity of an existing repeater, the station licensee must give written notification thereof to the Interference Office, Arecibo Observatory, HC3 Box 53995, Arecibo, Puerto Rico 00612, in writing or electronically, of the technical parameters of the proposal. Licensees who choose to transmit information electronically should e-mail to: prcz@naic.edu
    1) The notification shall state the geographical coordinates of the antenna (NAD–83 datum), antenna height above mean sea level (AMSL), antenna center of radiation above ground level (AGL), antenna directivity and gain, proposed frequency and FCC Rule Part, type of emission, effective radiated power, and whether the proposed use is itinerant. Licensees may wish to consult interference guidelines provided by Cornell University.
    2) If an objection to the proposed operation is received by the FCC from the Arecibo Observatory, Arecibo, Puerto Rico, within 20 days from the date of notification, the FCC will consider all aspects of the problem and take whatever action is deemed appropriate. The licensee will be required to make reasonable efforts in order to resolve or mitigate any potential interference problem with the Arecibo Observatory.

Personal Thoughts and Comments:

The FCC rules don't specify the method(s) that can be used to actually control a repeater or auxiliary station. DTMF is probably the most common, but various other signaling methods can be used, such as CTCSS/PL, DCS/DPL, MDC, single tone, and even voice. Any of these can be performed over-the-air or through a phone line.

If the repeater malfunctions, there has to be a positive way of turning it off. Most repeater controllers have an input timeout of around 3 minutes, so if the receiver somehow causes the repeater to transmit continuously, it should shut off after 3 minutes or so. Similarly, if a user's radio transmits for that much time, the repeater will shut down. But if a user goes on and on and starts making illegal transmissions, it may be difficult for a control operator to override such transmissions and activate the control system. In cases like this, the strongest signal wins, and if someone is sitting at the base of your repeater's tower drinking and swearing over the radio, there's not much you can do about it with over-the-air control, at least not right away.

In situations like this, a separate control receiver or a phone line provides a nearly guaranteed mechanism for accessing the repeater controller. Still, the phone line could be cut, or some other signal could block the control receiver, but these are probably considered acceptable risks.

Contact Information:

The compiler may be contacted at: his-callsign [ at ] comcast [ dot ] net.

This article is dedicated to Robert F. Brill, W1GC (ex WA1TJT) who passed away August 8th 2011. I knew Bob since he got his license in the mid 1970s and he was a very good friend. In 1970 I worked for Fred Brill, W1GC. After he died, Bob acquired his father's call sign in the 1990s. He and I had actually discussed this very topic several years ago. He will be missed by all who knew him.

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This page originally posted on 14-Aug-2011.

This web page, this web site, the information presented in and on its pages and in these modifications and conversions is © Copyrighted 1995 and (date of last update) by Kevin Custer W3KKC and multiple originating authors. All Rights Reserved, including that of paper and web publication elsewhere.