QRP operation - AbsoluteAstronomy.com

Amateur radio

Amateur radio is the use of designated radio frequency spectrum for purposes of private recreation, non-commercial exchange of messages, wireless experimentation, self-training, and emergency communication...

, QRP operation means transmitting at reduced power levels while aiming to maximize one's effective range while doing so. The term QRP derives from the standard Q code

Q code

The Q code is a standardized collection of three-letter message encodings, also known as a brevity code, all of which start with the letter "Q", initially developed for commercial radiotelegraph communication, and later adopted by other radio services, especially amateur radio...

used in radio communications, where "QRP" and "QRP?" are used to request, "Reduce power," and ask "Should I reduce power?" respectively. The opposite of QRP is QRO, or high-power operation.

Philosophy

Most amateurs use approximately 100 watts of power, and in some parts of the world like the US, can use up to 1500 watts. QRP enthusiasts contend that this is not always necessary, and doing so wastes power, increases the likelihood of causing interference

Electromagnetic interference

Electromagnetic interference is disturbance that affects an electrical circuit due to either electromagnetic induction or electromagnetic radiation emitted from an external source. The disturbance may interrupt, obstruct, or otherwise degrade or limit the effective performance of the circuit...

to nearby televisions, radios

Receiver (radio)

A radio receiver converts signals from a radio antenna to a usable form. It uses electronic filters to separate a wanted radio frequency signal from all other signals, the electronic amplifier increases the level suitable for further processing, and finally recovers the desired information through...

, and telephones and, for United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

' amateurs is incompatible with FCC

Federal Communications Commission

The Federal Communications Commission is an independent agency of the United States government, created, Congressional statute , and with the majority of its commissioners appointed by the current President. The FCC works towards six goals in the areas of broadband, competition, the spectrum, the...

Part 97 rule, which states that one must use "the minimum power necessary to carry out the desired communications."

Practice

There is not complete agreement on what constitutes QRP power. While most QRP enthusiasts agree that for CW

Morse code

Morse code is a method of transmitting textual information as a series of on-off tones, lights, or clicks that can be directly understood by a skilled listener or observer without special equipment...

, AM

Amplitude modulation

Amplitude modulation is a technique used in electronic communication, most commonly for transmitting information via a radio carrier wave. AM works by varying the strength of the transmitted signal in relation to the information being sent...

, FM

Frequency modulation

In telecommunications and signal processing, frequency modulation conveys information over a carrier wave by varying its instantaneous frequency. This contrasts with amplitude modulation, in which the amplitude of the carrier is varied while its frequency remains constant...

, and data

Data

The term data refers to qualitative or quantitative attributes of a variable or set of variables. Data are typically the results of measurements and can be the basis of graphs, images, or observations of a set of variables. Data are often viewed as the lowest level of abstraction from which...

modes

Modulation

In electronics and telecommunications, modulation is the process of varying one or more properties of a high-frequency periodic waveform, called the carrier signal, with a modulating signal which typically contains information to be transmitted...

, the transmitter

Transmitter

In electronics and telecommunications a transmitter or radio transmitter is an electronic device which, with the aid of an antenna, produces radio waves. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating...

output power

Transmitter power output

In radio transmission, transmitter power output is the actual amount of power of radio frequency energy that a transmitter produces at its output....

should be 5 watt

Watt

The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...

s (or less), the maximum output power for SSB

Single-sideband modulation

Single-sideband modulation or Single-sideband suppressed-carrier is a refinement of amplitude modulation that more efficiently uses electrical power and bandwidth....

(single sideband) is not always agreed upon. Some believe that the power should be no more than 10 watts peak envelope power

Peak envelope power

Peak envelope power is the average power supplied to the antenna transmission line by a transmitter during one radio frequency cycle at the crest of the modulation envelope, under normal operating conditions. The United States Federal Communications Commission uses PEP to set maximum power...

(PEP), while others strongly hold that the power limit should be 5 watts. QRPers are known to use even less than five watts, sometimes operating with as little as 100 milliwatts or even less. Extremely low power—1 watt and below—is often referred to by hobbyists as QRPp.

Communicating using QRP can be difficult since the QRPer must face the same challenges of radio propagation

Radio propagation

Radio propagation is the behavior of radio waves when they are transmitted, or propagated from one point on the Earth to another, or into various parts of the atmosphere...

faced by amateurs using higher power levels, but with the inherent disadvantages associated with having a weaker signal on the receiving end, all other things being equal. QRP aficionados try to make up for this through more efficient antenna

Antenna (radio)

An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...

systems and enhanced operating skills.

QRP is especially popular with CW

Morse code

operators and those using the newer digital modes. PSK31

PSK31

PSK31 or "Phase Shift Keying, 31 Baud" is a digital radio modulation mode, used primarily in the amateur radio field to conduct real-time keyboard-to-keyboard informal text chat between amateur radio operators.- History :...

is a highly efficient, narrow-band mode that is very suitable to QRP operation.

Equipment

Many of the larger, more powerful commercial transceivers permit the operator to lower their output level to QRP levels. Commercial transceivers

Two-way radio

A two-way radio is a radio that can both transmit and receive , unlike a broadcast receiver which only receives content. The term refers to a personal radio transceiver that allows the operator to have a two-way conversation with other similar radios operating on the same radio frequency...

specially designed to operate at or near QRP power levels have been commercially available since the late 1960s. In 1969, American manufacturer, Ten-Tec, produced the Powermite-1 (PM-1). This radio was one of Ten-Tec's first assembled transceivers. (The MR-1 was available, and it was essentially the same radio, albeit in kit form.) This radio featured modular construction (all stages of the transceiver were on individual circuit boards

Printed circuit board

A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...

): the transmitter was capable of about one or two watts of RF, and the receiver was a direct-conversion

Direct-conversion receiver

A direct-conversion receiver , also known as homodyne, synchrodyne, or zero-IF receiver, is a radio receiver design that demodulates the incoming radio signal using synchronous detection driven by a local oscillator whose frequency is identical to, or very close to the carrier frequency of the...

unit, similar to that found in the Heathkit

Heathkit

Heathkits were products of the Heath Company, Benton Harbor, Michigan. Their products included electronic test equipment, high fidelity home audio equipment, television receivers, amateur radio equipment, electronic ignition conversion modules for early model cars with point style ignitions, and...

HW-7 and HW-8 lines. Many amateurs became quite adept at QRP'ing through their use of these early, trend-setting radios. As QRP has become more popular in recent years, radio manufacturers have introduced radios specifically intended for the QRP enthusiast. Popular US models include Elecraft K2 and K1, the Yaesu

Yaesu (brand)

Yaesu is an international brand of commercial and amateur radio equipment.It was founded as in 1959 by a Japanese radio amateur Sako Hasegawa with callsign JA1MP in the Tokyo neighborhood of Yaesu...

FT-817, the Icom IC-703, and the Argonaut V from TenTec. Popular German QRP transceiver kits include the Moskita, Sparrow, Hegau, Hohentwiel, Tramp-8 CW and others. Another popular source is Hendricks QRP Kits, which offers a variety of popular kits. HFPack enthusiasts operate QRP radios on the HF

High frequency

High frequency radio frequencies are between 3 and 30 MHz. Also known as the decameter band or decameter wave as the wavelengths range from one to ten decameters . Frequencies immediately below HF are denoted Medium-frequency , and the next higher frequencies are known as Very high frequency...

bands in portable modes, usually carrying the radios in backpacks, with whip antenna

Whip antenna

A whip antenna is an antenna consisting of a single straight flexible wire or rod, often mounted above some type of conducting surface called a ground plane. The bottom end of the whip is connected to the radio receiver or transmitter. They are designed to be flexible so that they won't break...

s.

Some QRPers prefer to construct their equipment from kits or homebrew

Amateur radio homebrew

-History:In the early years of amateur radio, long before factory-built gear was easily available, most hams built their own transmitting and receiving equipment, a process that came to be known as "homebrewing." In the 1930s, 40s, and 50s, hams handcrafted reasonable-quality vacuum tube-based...

it from scratch.

Contests and awards

There are specific operating awards, contests

Contesting

Contesting is a competitive activity pursued by amateur radio operators. In a contest, an amateur radio station, which may be operated by an individual or a team, seeks to contact as many other amateur radio stations as possible in a given period of time and exchange information...

, clubs, and conventions

Convention (meeting)

A convention, in the sense of a meeting, is a gathering of individuals who meet at an arranged place and time in order to discuss or engage in some common interest. The most common conventions are based upon industry, profession, and fandom...

devoted to QRP enthusiasts.

In the USA, the November Sweepstakes, June and September VHF QSO Parties, January VHF Sweepstakes, and the ARRL International DX Contest, as well as many major international contests have designated special QRP categories. For example, during the annual ARRL's Field Day

Field Day

Field Day is an annual amateur radio exercise, widely sponsored by IARU regions and member organizations, encouraging emergency communications preparedness among amateur radio operators...

contest, making a QSO (ham-to-ham contact) using "QRP battery power" is worth five times as many points as a contact made by conventional means.

The QRP ARCI club sponsors 12 contests during the year specifically for QRP operators. QRP-ARCI Contests

Typical awards include the QRP ARCI club's "thousand-miles-per-watt" award, available to anyone presenting evidence of a qualifying contact. QRP ARCI also offers special awards for achieving the ARRL's Worked All States

Worked All States

Worked All States, or WAS, is an amateur radio operating award given to those amateur radio operators who successfully complete two-way amateur radio communications with other amateur radio stations located in each of the 50 United States of America . The award is sponsored by the American Radio...

, Worked All Continents

Worked All Continents

Worked All Continents, or WAC, is an amateur radio award given to those amateur radio operators who successfully complete two-way amateur radio communications with other amateur radio stations located in each of six continental areas of the world...

, and DX Century Club

DX Century Club

The DX Century Club, or DXCC, is an amateur radio operating award earned by making contact with 100 or more geographic entities around the world....

awards under QRP conditions. Other QRP clubs also offer similar versions of these awards, as well as general QRP operating achievement awards.

External links

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