Iran International TV on shortwave: why a modern news channel is turning back to HF broadcasting

Iran International TV has recently attracted attention across shortwave radio communities after reports emerged that the station’s audio is being relayed on shortwave frequencies via Spaceline facilities in Bulgaria. For many casual media consumers, this may sound unusual. A modern television news channel, available through satellite, internet platforms and digital distribution, is now also being heard on traditional shortwave radio bands.

For radio listeners, media analysts and anyone interested in resilient communications, this is more than a technical curiosity. It is a reminder that shortwave broadcasting still has a strategic role in the 21st century. While the internet dominates everyday media consumption, shortwave remains one of the few mass communication technologies that can cross borders without relying on local telecom infrastructure, local internet providers, app stores, mobile networks or domestic broadcasting licenses.

According to monitoring reports circulating among shortwave listeners, Iran International TV’s Persian-language audio has been heard on several HF frequencies. The commonly reported schedule includes 5890 kHz and 9525 kHz during overnight hours, with 15750 kHz and 17900 kHz used during daytime propagation periods. These transmissions are understood to be relayed through Spaceline’s Bulgarian shortwave infrastructure, most likely targeting listeners in and around Iran and the wider region.

The development matters because it sits at the intersection of broadcasting technology, censorship resistance, information access and geopolitical media strategy. It also shows why shortwave radio, despite decades of decline in mainstream consumer use, continues to appear whenever international news delivery becomes technically or politically contested.

What is happening

Iran International TV is not becoming a conventional shortwave radio station in the traditional sense. Instead, the audio feed of the television channel is being carried over shortwave transmitters. This means that listeners do not receive video content, but they can hear the spoken news, commentary, interviews and live programming from the channel using a shortwave receiver.

Technically, this is straightforward. A television news channel already produces a continuous audio feed. That audio can be routed to a transmission provider, modulated as a shortwave broadcast signal and transmitted through high-power HF antennas toward a target region. On the listener side, the result is a standard AM shortwave broadcast that can be received with an ordinary shortwave radio or SDR receiver.

The strategic meaning is more important than the technical process. Iran International TV is a politically sensitive Persian-language news outlet. For audiences in restricted media environments, the method of delivery is often as important as the content itself. If a website is blocked, a satellite signal is jammed, a social media account is restricted, or internet access becomes unreliable, alternative delivery paths become valuable.

Shortwave is one of those alternative paths. It is not modern in the consumer-interface sense, but it is robust, independent and difficult to suppress completely across a large area.

Why shortwave still matters

Shortwave broadcasting uses high-frequency radio waves that can travel long distances by reflecting from the ionosphere. Unlike FM radio, which is usually limited to local or regional line-of-sight coverage, shortwave can cross countries, seas and continents under the right propagation conditions.

That makes it useful for international broadcasting. A transmitter located outside the target country can still deliver programming into that country without needing domestic towers, local licensing, local internet service providers or physical distribution networks.

This is the central reason shortwave has historically been used by international broadcasters. During the Cold War, stations such as the BBC World Service, Voice of America, Radio Free Europe and many others relied heavily on shortwave to reach audiences behind political and informational barriers. The same basic logic still applies today, even though the technical environment has changed.

Modern audiences may prefer smartphones, streaming platforms and social media, but those systems depend on multiple layers of infrastructure and permission. A web service can be blocked. An app can be removed. A platform account can be restricted. A satellite signal can be jammed. A mobile network can be throttled or shut down. Shortwave is far less convenient, but it has one major advantage: the listener only needs a receiver.

A shortwave receiver is passive. It does not log in, does not reveal an IP address, does not depend on a SIM card and does not require a subscription. In environments where media access is monitored or controlled, that passive reception model can be highly relevant.

Why Bulgaria is a logical relay point

The reported use of Spaceline facilities in Bulgaria makes technical and geographic sense. Bulgaria is located in southeastern Europe, relatively well positioned for shortwave paths toward the Middle East, Iran, Turkey, the Caucasus and surrounding regions.

For HF broadcasting, geography matters. The location of the transmitter, the target area, the chosen frequency, the antenna beam direction, time of day, season and solar conditions all affect signal strength and reliability. A southeastern European transmitter site can be well suited for coverage into western Asia and the broader region around Iran.

There is also an infrastructure reason. Parts of Eastern Europe retain large shortwave transmission sites originally built during an era when international broadcasting was a major state-level communication tool. While many national broadcasters have reduced or closed their own shortwave services, some transmitter sites continue to operate commercially. They can lease airtime to international broadcasters, religious organizations, political media services and other clients that need long-distance radio coverage.

This commercial relay model is important. A broadcaster does not need to own a shortwave site. It can contract transmission time from an existing provider with high-power transmitters, directional antennas and technical staff already in place.

Why multiple frequencies are used

The reported frequency pattern is also technically reasonable. Shortwave propagation changes throughout the day. Lower HF frequencies tend to perform better at night, while higher HF frequencies often work better during daylight hours, especially over longer paths.

That is why a station may use one group of frequencies overnight and another group during the day.

The reported overnight frequencies around 5890 kHz and 9525 kHz fit the general logic of nighttime and transitional HF propagation. Lower shortwave bands can remain usable after dark because the ionospheric absorption pattern changes and longer-distance skywave propagation becomes more favorable.

The reported daytime frequencies around 15750 kHz and 17900 kHz fit a different propagation profile. Higher HF bands often need daylight ionization to support reliable long-distance paths. During periods of stronger solar activity, these higher frequencies can provide excellent regional or interregional coverage.

A multi-frequency strategy also improves resilience. If one frequency is weak because of propagation, another may still work. If one frequency is affected by interference or intentional jamming, listeners may be able to try another. This is one of the long-standing practices of international shortwave broadcasting: use several bands, adjust by time of day and change frequencies when conditions or interference require it.

The jamming problem

One of the main reasons this development is interesting is the possibility of signal jamming. Jamming is the deliberate transmission of noise, tones, music, data-like signals or other interference on or near a broadcast frequency in order to make reception difficult or impossible.

Shortwave jamming is not new. It was widely used during the Cold War against foreign broadcasters, when international radio services became part of a wider information conflict between rival political systems. The same historical background is explored in more detail in our article on Cold War radio jamming, including how states tried to block foreign news broadcasts with noise, tones and high-power interference signals. Listeners trying to hear international news services often encountered buzzing, roaring, siren-like tones, distorted audio or repetitive interference signals designed to mask the original program.

In the digital era, jamming has not disappeared. It has simply become part of a broader censorship and information-control toolkit. A state or state-aligned actor can attempt to block websites, throttle internet connections, restrict messaging platforms, interfere with satellite television and jam radio broadcasts at the same time.

This is why shortwave relays are both useful and vulnerable. They can bypass many local distribution controls, but they can still be jammed. The difference is that jamming a shortwave broadcast over a large area can require significant technical resources. It may also be imperfect. Depending on geography, propagation and receiver location, some listeners may still receive the target signal even when jamming is present.

Shortwave also allows broadcasters to react. They can change frequencies, add parallel channels, adjust transmission times, use different relay sites or shift to bands where jamming is less effective. This creates a technical contest between the broadcaster and the jammer.

Why a TV channel would use radio

At first, the idea of a television channel using shortwave radio may seem outdated. Video is more compelling than audio, and television news is designed around images, live visuals, graphics, studio presentation and on-screen context.

But news audio alone can still carry most of the essential information. Headlines, interviews, breaking news, political analysis, emergency updates and live commentary can all be understood without video. For a news channel, audio-only distribution is a practical fallback.

This is especially true when the purpose is not entertainment quality but access. If the audience cannot reliably watch the channel through satellite or online platforms, receiving the audio is still valuable. A radio relay can preserve the core informational function of the channel even when the visual medium is unavailable.

There is also a precedent for this approach. Television audio has often been repurposed for radio distribution, monitoring, emergency use or accessibility. In the case of international broadcasting, the distinction between television and radio becomes less important than the ability to move information across borders.

Shortwave as a censorship-resistant layer

Shortwave is not censorship-proof, but it is censorship-resistant in a specific technical sense. It reduces dependence on infrastructure controlled inside the target country.

An internet news service depends on DNS resolution, IP routing, hosting availability, platform access and user connectivity. A satellite television service depends on satellite capacity, uplink integrity, downlink reception and equipment access. A local FM or TV station depends on domestic transmitters and licensing. Shortwave, by contrast, can originate outside the target country and be received directly by individuals.

The receiving device is simple. A portable shortwave radio can operate on batteries. It can be used in remote areas. It can receive broadcasts without network registration. It leaves no digital trace comparable to visiting a website or using a mobile app.

This does not make shortwave a perfect solution. Reception quality can be poor. Urban electrical noise can be severe. Many younger listeners do not own shortwave receivers. Frequency schedules can be confusing. Propagation varies. Jamming may occur. Still, the basic architecture remains powerful: one transmitter can reach many listeners over a wide area without the listeners needing to connect to a network.

For politically sensitive broadcasting, that architecture remains relevant.

The role of Spaceline and commercial shortwave relays

Commercial relay providers are now an important part of the shortwave ecosystem. As many state broadcasters reduced their own transmitter networks, privately operated or commercially available transmission sites became more visible. These sites sell airtime, technical delivery and geographic coverage.

A client can provide audio programming, and the relay operator handles the transmission chain. This may include frequency coordination, transmitter operation, antenna selection, monitoring and technical maintenance.

For a broadcaster like Iran International TV, this approach has practical advantages. It avoids the cost and complexity of owning a dedicated HF transmission facility. It also allows rapid deployment. If capacity is available, a new broadcast can appear quickly on scheduled frequencies.

This flexibility is one reason shortwave has not disappeared entirely. The number of major shortwave broadcasters has declined, but the infrastructure that remains can be repurposed for targeted missions. Religious broadcasting, international news, emergency communication, diaspora programming and political broadcasting all continue to use shortwave where it makes strategic sense.

A sign of information warfare

The return of a modern news channel to shortwave should be understood within the broader context of information warfare. Media access is now contested across multiple layers: broadcast, satellite, internet, social media, messaging apps and search platforms.

In this environment, redundancy matters. A broadcaster that relies on only one distribution channel is vulnerable. A broadcaster that uses multiple parallel channels can survive disruption more effectively.

Shortwave adds a non-internet, non-satellite, one-to-many broadcast path. It does not replace digital media, but it complements it. The same organization can distribute news through a website, streaming video, mobile apps, satellite television, social networks, podcasts and shortwave radio. Each channel has weaknesses. Together, they create a more resilient system.

This is why the Iran International TV shortwave relay is significant. It suggests that the organization, or those supporting its distribution strategy, sees value in a communication layer that many people assumed was obsolete. In practice, shortwave becomes relevant precisely when other channels are under pressure.

The decline and survival of shortwave broadcasting

Shortwave broadcasting has undeniably declined in many parts of the world. Major broadcasters have closed transmitters, reduced language services and moved resources to digital platforms. The reasons are understandable: shortwave is expensive to operate, energy-intensive, difficult to measure and less attractive to ordinary users than online media.

But decline is not the same as disappearance. Shortwave has survived because it solves a problem that other technologies do not solve as cleanly. It allows long-distance broadcasting into areas where the broadcaster has no local infrastructure and where the audience may not have reliable or free access to digital media.

The technology is old, but the use case is not. In fact, current geopolitical conditions may make the use case more relevant again. Internet shutdowns, satellite interference, cyberattacks, platform restrictions and state-level disinformation campaigns all increase the value of independent broadcast paths.

Shortwave is no longer the default mass medium for international news, but it remains a strategic medium. That distinction is important. Its value is not measured only by audience size in stable markets. Its value is measured by whether it can still deliver information when other channels fail.

What listeners may hear

Listeners monitoring the reported frequencies may hear Persian-language audio from Iran International TV. The content may include news bulletins, live studio discussion, political analysis, interviews and rolling coverage. Since the relay appears to carry television audio, the programming style may differ from a purpose-built radio station. There may be references to visuals, studio graphics or video clips that radio listeners cannot see.

Reception will vary. A signal that is strong in one location may be weak or absent in another. Shortwave listening depends heavily on propagation, receiver quality, antenna setup and local noise. The same frequency can sound clear on one evening and poor the next.

Listeners using software-defined radios can compare reception from different geographic locations. Online SDR platforms are especially useful for checking whether a signal is being received near the target region, in Europe or elsewhere. They can also help identify jamming, fading patterns and frequency changes.

For monitoring purposes, the most useful details to record are:

• frequency;
• UTC time;
• language;
• signal strength;
• interference level;
• audio quality;
• transmitter identification if heard;
• comparison with parallel frequencies;
• presence or absence of jamming.

Such monitoring reports are valuable because shortwave schedules are not always immediately reflected in public databases. The DX community often detects changes quickly through distributed observation.

Why the story spread quickly among radio sites

Shortwave listeners pay close attention to unusual signals, new relays and politically sensitive broadcasts. When a known television news outlet appears on multiple HF frequencies, especially in a context involving possible jamming, the news naturally spreads through radio forums, mailing lists, monitoring groups and frequency databases.

Several factors make this case especially noticeable:

• a high-profile Persian-language news channel;
• a politically sensitive target audience;
• use of a European shortwave relay site;
• multiple day and night frequencies;
• possible connection to anti-jamming strategy;
• renewed use of HF broadcasting by a modern digital-era media outlet;
• relevance to both technical radio monitoring and media freedom.

For the shortwave community, this is not simply another entry in a frequency list. It is a real-world example of why the HF spectrum still matters.

Technical limitations

Despite its strategic strengths, shortwave also has limitations. It is not a universal solution.

First, reception quality is unpredictable. Atmospheric noise, fading, seasonal changes, solar conditions and local interference can all affect listening. Even high-power transmitters cannot guarantee clear reception everywhere at all times.

Second, the audience needs suitable receivers. While shortwave radios are inexpensive compared with many communication devices, they are no longer common household items in many countries. Awareness is also an issue. People need to know which frequencies to use and when to listen.

Third, jamming remains a real threat. A determined jammer can make reception difficult, especially in areas close to the jammer’s transmitter. Multiple frequencies and relay sites can help, but they do not eliminate the problem.

Fourth, shortwave is audio-only in this use case. It cannot deliver the full television experience. It cannot provide images, subtitles, interactive features or on-demand playback.

These limitations explain why shortwave is best understood as a backup and resilience layer, not a replacement for digital media.

Why this matters beyond one broadcaster

The Iran International TV case has broader implications. It suggests that international broadcasters may continue to reassess older technologies as part of a multi-layer distribution strategy.

The modern media environment often rewards speed, convenience and analytics. Platforms can show how many users watched a video, clicked a link or installed an app. Shortwave does not provide that kind of precise measurement. But it provides something else: independence from the local digital gatekeepers of the target country.

For broadcasters operating in politically sensitive environments, that independence can be more important than measurement. It can preserve access to audiences during disruption. It can support emergency communication. It can provide a symbolic and practical countermeasure against censorship.

This may not lead to a broad revival of shortwave for general entertainment or everyday news consumption. But it may lead to more selective use of shortwave by organizations that need resilient international reach.

Shortwave in the age of satellites and streaming

It is easy to assume that satellites and streaming have made shortwave obsolete. In normal conditions, they often provide a better user experience. Satellite television offers video. Streaming offers on-demand access. Social media offers viral distribution. Messaging apps offer direct sharing.

But each of these systems has control points. Satellite signals can be jammed. Streaming services can be blocked. Social media accounts can be restricted. Messaging apps can be filtered. App stores can remove software. Payment systems can be interrupted. Domain names can be seized or blocked.

Shortwave has fewer control points on the receiving side. The transmitter is outside the target area, and the listener only receives. This does not make the system invulnerable, but it makes suppression more technically demanding.

The practical future of international media is therefore not old versus new. It is layered. A serious broadcaster may need both streaming and radio, both satellite and web, both social media and fallback broadcast paths. The Iran International TV relay is an example of this layered strategy in action.

What to watch next

Several developments will show whether this is a temporary response or a longer-term strategy.

The first is schedule stability. If the same frequencies and time blocks continue to appear, this may indicate an organized ongoing relay plan rather than a short test.

The second is the appearance of jamming. If interference follows the broadcasts across frequencies, that would confirm the sensitivity of the transmissions and may trigger further frequency adjustments.

The third is expansion or reduction. Additional frequencies, longer airtime or extra relay sites would suggest greater commitment. A sudden disappearance could indicate a short-term emergency measure or a change in distribution strategy.

The fourth is whether other broadcasters follow the same pattern. If more politically sensitive TV or digital news channels begin using shortwave audio relays, it would reinforce the idea that HF broadcasting is regaining importance as a resilience tool.

Why radio observers should document it

For shortwave listeners and technical observers, documenting these broadcasts is useful. Accurate logs help build a clearer picture of what is actually happening on the air. They can confirm schedules, detect jamming, identify transmitter behavior and track changes over time.

Good monitoring reports should include UTC time, exact frequency, receiver location, signal quality, interference description and any parallel frequencies checked. Audio recordings can also be valuable, especially when identifying jamming or verifying the program source.

This kind of distributed monitoring is one of the strengths of the shortwave community. No single listener can cover all bands and all regions, but many listeners together can create a detailed picture of international broadcasting activity.

A practical reminder about HF broadcasting

The Iran International TV shortwave relay is a reminder that HF broadcasting remains technically useful because it does something simple and rare: it sends information across borders without requiring the target audience to connect to a network.

That capability may seem outdated when everything works. It becomes important when things do not work.

In stable media environments, shortwave feels inconvenient. In contested media environments, it becomes resilient. That is the core reason the technology survives.

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