What equipment is needed to listen to HAARP radio transmissions?
Within Alaska, only an inexpensive portable shortwave radio receiver is needed to tune-in and listen to the HF radio transmissions from HAARP. Outside Alaska, a little luck in the form of favorable ionosphere conditions for radio propagation perhaps combined with a more sensitive shortwave radio are needed to receive HAARP broadcasts.
The HAARP transmitter can be tuned to transmit at arbitrary radio frequencies between approximately 2.7 and 10 MHz (i.e. 2700 to 10,000 kHz). This frequency range is between the AM and FM bands received by most consumer radios in home and automobile audio systems. The specific frequency chosen during a particular experiment depend on the experiment objectives, United States Federal Communications Commission (FCC) regulations, and ionosphere conditions at the time.
Most people are familiar with AM/FM radio receivers in home and automobile entertainment systems for listening to local and regional programming. FM radio uses frequency modulation to encode sounds with radio frequencies between 87.5 and 108 MHz while AM radio uses amplitude modulation to encode sounds with radio frequencies between 530 and 1700 kHz (0.530 and 1.700 MHz). Many people, particularly younger generations, may not be familiar with shortwave radio, which used to be the primary method of reaching global audiences with news, entertainment, and even government propaganda before the internet provided another medium with comparable reach. Shortwave radio, while diminished somewhat in terms of the number of stations broadcasting and the number of listeners, still retains an important purpose today as one means of listening to global programming without personally-identifying subscriptions or internet connections. Sounds are typically encoded for shortwave radio broadcasts with amplitude modulation using radio frequencies between 1.6 and 30 MHz.
The HAARP transmitter uses radio frequencies that can be received by many inexpensive portable shortwave radio receivers. Depending on the particular HAARP experiment, a listener with a shortwave radio tuned to the HAARP transmit frequency may hear quiet sounds devoid of static (similar to when the DJ at an active AM/FM radio station accidentally lets the music end without starting the next song), beeps, tones, whistles, and other sounds. Inexpensive portable shortwave radio receivers are sufficient to hear and record the HAARP modulation sounds with sufficient radio propagation conditions and knowledge of which frequency or frequencies to tune in. When choosing a shortwave radio receiver to listen to HAARP transmissions, make sure that the radio can receive the entire 2.7 to 10 MHz band available to HAARP since some shortwave radio models can be tuned to only a few smaller bands in that range.
Shortwave radios capable of receiving HAARP transmissions can be purchased through the following Amazon links. Providing these links is intended for informational purposes only and does not constitute an endorsement of a particular brand or vendor. These radios were chosen specifically because they provide easy digital tuning, can be tuned to any possible HAARP transmission frequency between 2.7 and 10 MHz, and cost less than approximately $100 USD. If you are aware of additional radios that meet these specifications, please let me know through the contact link at the top of this page so I can add them to this list.
(Update 18 Feb 2017) Thank you, DVH, for the additional following shortwave radio receiver recommendation!
(Update 19 Feb 2017) What if you do not have a radio? No problem! Use a Web Radio! That is, a radio somewhere with a web interface. Thank you, Harry et al., for suggesting the following sites.
Wide-band Web SDR (software defined radio) at the University of Twente
Global Tuners lets you control radio receivers located all over the world
RemoteHams.com has even more web-controllable radios
Ionosonde data that guides selection of HAARP radio transmission frequencies
An ionosonde is a type of variable- or swept-frequency high-frequency (HF) radar commonly used to measure the ionosphere plasma density and velocity overhead. Modern digital ionosondes are widely deployed and used for basic ionosphere research, real-time ionosphere plasma density and velocity measurements, real-time awareness of time-dependent HF radio propagation and absorption properties, and HF channel management. Users of ionosonde data include space and radio scientists, U.S. Department of Defense, emergency management officials, and Ham amateur radio operators. The HAARP ionosonde is used by scientists primarily to plan experiments, but it is also used to provide limited measurements about effects of HAARP ionosphere modification (HAARP modifies only a small fraction of the ionosphere "seen" by the ionosonde).
For HAARP experiment planning, scientists use the ionosonde to estimate two important parameters: (1) the amount of low level ionosphere D-region HF radio absorption that frequently occurs due to natural but not well understood processes that prevent HAARP radio wave energy from reaching the higher ionosphere E and F regions; and, (2) the ionosphere vertical "critical frequency" above which any radio transmissions pass through the ionosphere into space rather than being reflected or absorbed. Times of significant ionosphere D-region HF radio absorption are generally indicated by whether or not the ionosonde is providing useful data. The ionosphere critical frequency, sometimes referred to as foF2 in academic and technical literature, depends on the maximum number of electrons per unit volume overhead and, in the absence of disturbing factors such as solar or geomagnetic storms, varies diurnally to first order.
Most (but not all) HAARP experiments use powerful HF radio transmissions at frequencies near or below the ionosphere foF2. Therefore, if you know that a HAARP experiment campaign is in progress but do not know the actual radio frequency or frequencies used at the time, then knowing the current foF2 near Gakona can help narrow the possible frequencies in use by eliminating those above foF2. Measurements and ionograms from the HAARP ionosonde used to be available from the HAARP data page. That information is not yet available from the Geophysical Institute page but some of the data is available from LDI (Lowel Digisonde International), the manufacturer of the HAARP ionosonde.
About HF radio transmissions from HAARP
HAARP is essentially a large powerful radio transmitter, similar in some respects to commercial large radio stations and radar installations. Unlike a commercial radio station, where radio (electromagnetic) wave energy is usually radiated in all directions to reach the largest possible audience, most of the HAARP radio wave energy is radiated in a relatively narrow beam, steerable by approximately 30 degrees off the vertical direction. Another unique feature of HAARP is that it can be tuned to transmit at any legally allowed radio frequency between approximately 2.7 and 10 MHz, or even two frequencies simultaneously. Radio waves in this HF band can often propagate large distances, sometimes completely around the Earth, by successively reflecting off the ionosphere, the Earth surface, and the oceans. (Radio waves with higher frequencies usually do not reflect from the ionosphere and simply pass through to deep space.)
Example audio recordings of HAARP radio broadcasts
There are several examples of HAARP broadcasts available online. Some of these examples were recorded intentionally due to prior announcement of HAARP activities, and some were recorded by happenstance by hobbyists who monitor the radio spectrum. If you know of other online examples of recorded HAARP transmissions please share them with me through the contact link at the top of this page so I can add them to the list below.
Moon bounce (HAARP was "aimed" at the moon to duplicate a favorite ham radio communication mode)
Luxembourg effect (HAARP transmitted two audio tracks at different radio frequencies simultaneously to duplicate the Luxembourg effect. See the hissingchorusofdawn Soundcloud links from the linked NPR All Things Considered article.)
HAARP Oddities at 2.75 MHz Recording from the Mojave Desert of a HAARP transmission with a ULF amplitude modulation
HAARP Oddities at 5.8 MHz Recording of a HAARP transmission with an linear ramp amplitude modulation
(Update 18 Feb 2017) Thank you, Adam C., for finding and sending the following links to additional online recordings of HAARP transmissions made by good listeners! (I haven't had a chance to verify these in the HAARP operation logs yet but I have listened to each and they sound consistent with other HAARP experiments I've previously heard.)
HAARP Sound 5/4-5/12 3250KHZ to 5500KHZ (it's complicated)
HAARP Woodpecker and other sounds 2750- 4500KHZ (somebody has a cool radio!)
HAARP tones on 3250khz (2-18-2012) (sequences of dual tones or harmonic intervals)
Oddities Station, HAARP, July 24, 2011, 0818 UTC, 2750 kHz (example of 100 kHz bandwidth, the technical limit at HAARP without retuning to a new center frequency)
Where and how to tune-in to HAARP radio broadcasts
All you need to listen to HAARP transmissions is a shortwave radio such as one of the models listed above, a little knowledge about when HAARP is operating, the radio frequency that HAARP is transmitting, and a little bit of luck in the form of favorable radio propagation conditions. News about HAARP transmitting times and frequencies, at least for selected NSF-funded experiments, can be found on the Operations page.