During World War II, Imperial Japan banned the use of shortwave radios, which tech savvy Koreans were apparently using to secretly listen to the Korean-language service of the Voice of America, which began broadcasting in August 1942. Doing so was extremely risky, since anyone who was caught by Imperial military police faced detention by Inspector Saiga Shichirō, who was notorious for fabricating cases and brutally torturing and killing detainees.
By 1944, a few hundred Koreans were arrested for shortwave radio offenses. Thus, the number of shortwave listeners was probably extremely small, numbering maybe only a few hundred in a population of over 25 million. Nevertheless, it is a testament to the insecurities of the totalitarian regime that it went to such great lengths to crack down on such a tiny circle of listeners, presumably because uncensored news about the war threatened its monopoly over information and challenged its control over the minds of the Korean people. The ominous final paragraphs of the article, hinting at further rounds of arrests, appear calculated to frighten anyone who might still have been listening.
Also reproduced here is a news advertisement from the July 20, 1938, issue of Keijo Nippo newspaper illustrating an example of an AM radio set, which might have been modified by Korean hackers to receive shortwave signals. This particular model is a Sharp M-3 radio set manufactured by Hayakawa Electric, a precursor of the modern Sharp Corporation.
By the late 1930s, technology had progressed enough that the size of the radio sets had shrunk to that of a toaster, and only four vacuum tubes were required to operate it. But the four vacuum tubes had to be specific types: UZ 57, UX 26B, UX 12A, and KX 12F. It is a testament to the resilience and technical expertise of this underground Korean radio hacker community that they were still able to scrounge up enough parts amid wartime shortages and work clandestinely under the noses of the vigilant Imperial police and its informants to even be able to listen to the shortwave broadcasts from the U.S. and breach the regime's information blockade.
I am also documenting four other articles demonstrating just how closely radio ownership and listening were controlled in colonial Korea. Receiver installations required official permission, and the authorities periodically threatened to prosecute people who listened without authorization. I also included articles from 1942 and 1943 reminding the Korean people of the ongoing ban on shortwave radio.
[Translation]
Gyeongseong Ilbo (Keijo Nippo), November 25, 1944
Criminals Who Leave No Trail
Meeting Technical Skill with Technical Skill
Inspector Saiga’s Keen Instinct for Uncovering Clandestine Shortwave Listening
In a remarkably short period of only six months, Inspector Saiga Shichirō of the Special Higher Police Section of the Gyeonggi Provincial Police Department apprehended [redacted] persons involved in clandestinely listening to shortwave broadcasts and seized fifty radio sets. These traitorous individuals had allowed themselves to be captivated by enemy schemes and, posing as well-informed persons, had spread false broadcasts throughout the community as though they were true. For his outstanding achievement in forestalling such subversive activity, Saiga received Korea’s first Police Distinguished Service Award. We asked him to describe the full scope of clandestine shortwave listening.
“While investigating a particular rumor case, we traced it to information that ordinarily could not have been obtained in Korea. Suspecting that shortwave radio was undoubtedly involved, we extended our investigation in every direction, examining connections with dealers as well as with technicians. I shall never forget that we began the investigation on the Day of the Imperial Rescript on February 8, 1943.”
“Even the largest case sounds perfectly simple once it has been solved, but making the arrests was anything but easy. If someone is transmitting radio waves, the source can be located with detection equipment. Reception, however, is different. We had to consider the equipment, its outward appearance, and other circumstances together, identify suspicious persons, and then proceed to arrest them. In practice, this was an extremely difficult problem.”
“As our surveillance expanded, their methods became more ingenious. A set might outwardly be a model certified by the Broadcasting Corporation, while its interior had been skillfully modified, allowing the owner to feign complete innocence. We started seizing actual radio sets only in February. As the investigation became more severe in April and May, suspects began burying receivers in the ground or dividing their component parts into three or four separate hiding places. Even when our preliminary investigation had already secured conclusive evidence, we sometimes had to search a house three times before finally discovering a single component. Technically speaking, their methods were quite sophisticated.”
Inspector Saiga’s skill in dealing with shortwave equipment, relentlessly examining even the smallest and most ordinary-looking component, was cultivated during his military service thirty years ago. As a signals soldier, Private First Class Saiga underwent extensive technical training and devoted himself to operational communications during the Siberian Intervention. By a curious turn of fate, the confidence he gained in those skills has now proved of great value in the Greater East Asia War.
“Even an ordinary radio is difficult to hear when improperly adjusted. With shortwave, clandestine listening is impossible without at least some technical knowledge. Anyone who succeeded in listening had probably ruined one or two radios while learning. From a technical standpoint, therefore, the offenders came from the so-called intelligentsia: people with wireless expertise, people who had studied it at school, or radio dealers.”
“From the police standpoint, the investigation proceeded by following rumors back toward their sources. But the trail often broke off midway and could not easily be followed. People often speak of arrests proceeding 'like pulling up a sweet-potato vine,' with one suspect leading to another, but matters were not so simple in this case.”
“There was, however, technical cooperation among the listeners. One member might say to another, 'I haven't been able to listen very well with mine in recent days. What could be wrong with it? Take a quick look at it for me.'”
“Of the 246 persons who became involved in the investigation, [redacted] persons were convicted. Among them were some pitiable cases, including persons who listened because close relatives were living in the continental United States and they were anxious about their safety. Nevertheless, unlawful equipment remains unlawful equipment, and they had to face the judgment of the law.”
“There was also one admirable person who, despite being exposed to outrageous falsehoods, maintained an iron resolve and personally rejected the subversive rumors.”
“Although women are ordinarily associated with criminal cases, none appeared to have been involved in clandestine shortwave listening. This may have been because of the technical knowledge that the activity required.”
Inspector Saiga believes that the practice has probably been eradicated in terms of its overall scale, but that truly malicious individuals may still be listening secretly. Perhaps he is already devising confidential plans for a second and third round of arrests.
“Work that anyone can undertake can be left to others. I do what no one else will attempt,” says Inspector Saiga. What will be the next achievement credited to him?
Gyeongseong Ilbo (Keijo Nippo), June 29, 1943
Controls on the Sale of Radio Receivers
As stronger restrictions on the supply and demand of important materials have made radio receivers and their components increasingly difficult to obtain, the Communications Bureau has decided to regulate their distribution and sale. Therefore, Mr. Fukagawa, chief of the bureau’s Supervisory Section, issued the following statement:
“The allocation of materials for radio receivers and components has recently become considerably tighter. Consequently, we can no longer supply people who wish to use a high-grade receiver merely as an ornament in a room or who unnecessarily install two or more sets.”
“From now on, distribution will be controlled according to a one-receiver-per-household principle, with the objective of making simple and inexpensive receivers widely available. Specifically:”
“1. Requests will not be accepted from persons who already possess a receiver and wish to purchase an additional one, or who wish to purchase a more advanced receiver.”
“2. In places where broadcasts can be received easily, such as cities in which broadcasting stations are located and nearby areas, only simple, inexpensive receivers will be sold, and the sale of high-grade receivers will be prohibited.”
“We particularly ask everyone not to leave the nation’s precious resources sitting idle, but to put them to effective use for listening. If a receiver is no longer needed, please transfer it to someone who requires one. Those possessing two or more receivers should transfer any unnecessary sets to others so that they may be put to use. We also ask listeners to carefully handle the receivers that they are presently using.”
Gyeongseong Ilbo (Keijo Nippo), June 26, 1943
The Growing Number of Radio Listeners
Unlicensed Listeners Should Complete the Required Procedures Immediately
Under the conditions of the Greater East Asia War, in which every day is a decisive battle, radio has cast off its former entertainment-centered role. It has become an indispensable part of national life and an important weapon for defending the home front.
The number of listeners continues to rise rapidly. During the five-day period, 6,372 new applications were submitted. On the other hand, 4,976 listening registrations were terminated because receivers had been sold, had broken down, or because their owners had moved elsewhere within or outside Korea. This produced a net increase of 1,396, bringing the total number of registered listeners to 270,854.
A considerable number of people, however, are still listening without having obtained permission, or have reported that they have discontinued listening while continuing to do so. The Communications Bureau, acting in coordination with the Broadcasting Corporation, will shortly conduct simultaneous arrests for these unlawful installations.
Because unlawful radio installations are subject to severe punishment under the Electronic Telecommunications Act, the Communications Bureau urges anyone who has not yet obtained permission to complete the required procedures immediately.
Gyeongseong Ilbo (Keijo Nippo), March 12, 1943
Shortwave Receivers Are Forbidden
Anyone Possessing One Must Report It Immediately
Across the skies of the world, a battle of radio waves is unfolding that nothing can obstruct. Radio waves, as “invisible bullets,” transcend time and distance to strike at the heart of the enemy.
The enemy, groaning under defeat, is attempting to compensate for its military disadvantage through schemes and propaganda conducted by radio broadcast. It is expected to intensify its false propaganda in the future in an effort to disrupt our home front.
For this reason, the Communications Bureau prohibited last summer the use of equipment capable of intercepting enemy false broadcasts, namely, shortwave receivers. Perhaps because radio listeners in Korea have not fully understood the purpose of the prohibition, some have failed to report their sets and have continued listening secretly without obtaining permission. More than ten such persons have already been uncovered.
The Communications Bureau urges anyone who has a shortwave receiver in his possession to come forward voluntarily before being discovered and punished.
Gyeongseong Ilbo (Keijo Nippo), September 9, 1942
Shortwave Reception Absolutely Prohibited
Severe Punishment for Unreported Listening
Do you possess a shortwave receiver or an all-wave receiver?
For counterespionage reasons under the present wartime conditions, such receivers are absolutely prohibited. Any private individual possessing one must report it immediately to the Communications Bureau, a police station, or the military police, or face punishment.
Those who are using a receiver after partially disabling its shortwave or longwave section are also requested to consult the Communications Bureau or the Broadcasting Corporation regarding the extent of the modification and to take the prescribed measures.
Domestic radio receivers, foreign-made receivers other than models certified by the Broadcasting Corporation, and specially constructed receivers, such as homemade sets, are prohibited if their reception range extends below 550 kHz or above 1,500 kHz.
Anyone possessing such a set must report it, submit it for inspection, and obtain instructions concerning the appropriate measures to be taken. If the set is subsequently discovered, its owner will be severely punished regardless of whether the owner possesses a broadcast-listening permit. The Communications Bureau urges everyone to comply so that no mistakes happen.
[Transcription]
京城日報 1944年11月25日
蔓を持たぬ犯人
技術には技術で
短波密聴に鋭い斎賀警部の勘
敵の謀略にうつつを脱かし物識顔でデマ放送をまことしやかに巷間に流布する短波密聴の売国奴どもを僅か六ヶ月の短期間に関係者〇〇名と五十台の機械を取り押さえ、謀略を未然に防いだ抜群の功で朝鮮最初の警察功績賞を受けた京畿道警察部高等警察課警部斎賀七郎氏に短波密聴の全貌を聴いた。
『ある流言事件の査察をしているうち鮮内で普通には知り得られない流言に辿りつき、これは確かに短波が使用されているという睨みから業者の関係、技術者の関係と各方面から査察の手をのばした。取調を開始したのは忘れもしない昭和十八年二月八日の大詔奉戴日であった』
『どんな大きな事件でも片付いたあとからの話は至極簡単だが検挙は並大抵のものではない。電波を放射する発信なら探知機で突止めることも出来るが、受信となると施設或は外見といった点から綜合して怪しいと狙ったのを検挙してゆくのだから実際にはなかなか困難な問題であった。警戒の手が伸びると巧妙になって外見は放送協会の認定品でありながら実際は内部を巧みに改造して素知らぬ顔をしているといった不逞さであった。現物の押収は二月だけで四月、五月と取調べが峻厳になるにつれ受信機を土の中に隠したり部分品を三つにも四つにも分け、内査では確証を握っておりながら家宅捜査を三回繰返して漸く部分品の一つをさがし出すといった調子で技術的には相当なものだった』
何の変哲もない小さな部分品にまで査察の眼を離さず執拗に喰下る斎賀警部の短波に対する腕の冴えは三十年前の兵営生活に育まれているのだ。通信兵として技術の修練を積んだ斎賀上等兵はシベリア出兵で作戦通信に挺身した腕に覚えの自信がいま大東亜戦争に大きく役立ったのも不思議な因縁だ。
普通のラジオでさえ調節が悪ければ聴きづらいのに、まして短波になると曲りなりにも技術を知らなければ密聴は出来ない。密聴するまでにはラジオの一つや二つは壊したことであろうから機械的には無線の技術をもったものとか学校で習ったもの或はラジオ商といった範囲の所謂インテリ層なのだ。また一方警察的には流言を辿るのだが途中で根が切れてなかなか辿れない場合が多い。よく芋蔓式というが、この場合はそう簡単にはゆかない。然し技術的協力ということはある。つまり自分のは最近聞えないが、どうした調子だろう。一寸検べてくれといった仲間同志の技術の協力だ。迷惑のかかった二百四十六名のうちから〇〇名が有罪となったのだが、なかには肉親が米本土にいるのでその安否を気づかって聴いていたという気の毒な人もあったが、不法施設はあくまで不法施設であって法の裁きは受けねばならないのだ。また或人はとんでもないデマを吹込まれながら鉄壁の決意をもって不逞のデマを自ら打ち砕いていた奇特な人もあった。
犯罪には女がつきものであるにかかわらず、短波の密聴に女が関連していないのも技術といった点から姿が見えなかったのかも知れない。
量的には壊滅したであろうが本質的に悪い奴は今なお密聴しているだろうという斎賀警部の胸中には第二、第三の検挙の秘策が練られているのかもしれない。誰もが手につけるような仕事は他人まかせだ、俺は人が手をつけないことをするという斎賀警部の手に挙がる次の戦果は果して何であろう。
京城日報 1943年6月29日
受信機の販売統制
重要物資の需給制限強化によりラジオの受信機や部分品の入手も相当困難となって来たので逓信局では配給販売を統制することになったが、右に関し逓信局深川監理課長は次の通り談話を発表した。
ラジオの受信機や部分品用材の割当は最近相当窮屈になって来たので今迄のように高級受信機を部屋の飾物にしたり不必要に二個以上据付けるというような向きには配給出来なくなった。今後はこれを統制して次の如く一戸一機主義により簡易低廉な受信機を広く普及する方針にした。即ち、
一、受信機所持者が増設する為に購入せんとするもの又は更に高級受信機を購入せんとするものには応じない。
二、放送局所在地や近距離の所など容易に聴取出来る地では簡易低廉な受信機を販売し高級受信機の販売を禁止する。なお此際特に御願いしたいことは貴重な国家の資源を遊ばすことなく有効に聴いて戴きたい。若し不用ならば必要な向きに譲って貰い二個以上あって不用なものは他に譲って活用して戴きたい。又現在聴取している受信機は大切に取扱って戴きたい。
京城日報 1943年6月26日
増えるラジオ聴取者
無許可者は早速手続を
その日その日が決戦である大東亜戦下のラジオは従来の娯楽本位から脱皮し国民生活と切離すことの出来ない銃後を守る大切な武器となり、聴取者はぐんぐん増加の一途を辿り、五日中の新規申込者は六千三百七十二名であったが、一方受信機の売却、故障、内外地転出で廃止が四千九百七十六名もあり、結局千三百九十六名の純増で総数二十七万八百五十四名となった。
この中には未だに許可を受けずに聴いているもの又は聴取廃止をし、そのまま聴いている者が相当あるので逓信局では放送協会と連絡して之等不法施設の一斉検挙を近く行うが、ラジオの不法施設は電信法により厳重処罰されることになっているから未だ許可を受けていないものはこの際至急手続きをとるよう逓信局では要望している。
京城日報 1943年3月12日
短波受信機はご法度
所持する者は今直ぐ届出よ
世界の空には何物にもさえぎることの出来ない電波の攻防戦が展開されている。電波は『見えない弾丸』として時間と距離を超越し敵国の心臓を衝く。敗戦に喘ぐ敵側は武力の不利をラジオ放送による謀略と宣伝戦で補わんと我が銃後攪乱のため今後ますます熾烈なデマ宣伝を企図するものと考えられるので、逓信局では昨夏敵国のデマ放送を傍取し得る機械即ち短波受信機の使用を禁止したが、鮮内のラジオ聴取者には趣旨の不徹底のためか届出を怠り、使用許可を得ずしてひそかに聴取しているもので摘発されたものも十数名にのぼっているが、逓信局では手元に短波受信機を持っているものは摘発をうけ処罰されないうちに自発的に申出るよう要望している。
京城日報 1942年9月9日
短波は絶対禁止
無届聴取は厳重処罰
短波受信機または全波受信機をお持ちの方はありませんか。時局下防諜上の見地から絶対禁止せられているから若し一般の方で、これ等の受信機を持っている方は至急逓信局なり警察署、憲兵隊に申出ないと処罰されます。短波または長波部分を一部切断して聴取している方も改装の程度を逓信局か放送協会に問合わせの上処置せられるよう逓信局では要望している。
国産のラジオ受信機或は放送協会認定品以外の外国製の受信機または自分で組立てたような特殊の受信機で五百五十キロサークルから千五百キロサークルを超えるものは禁止品となっているから届出をなし検査を受け適当な処置を仰いでいないと後日発見されたとき放送聴取許可証の有無に拘わらず厳重処罰されるから間違いの起こらないよう逓信局では要望している。
Sources:
- Digital Newspaper Archive, National Library of Korea
- Internet Archive (Keijo Nippo; June 29, 1943; page 3) (link)
See also:
- Saiga Shichirō (斎賀七郎), an Imperial Japanese Ideological Police officer responsible for the torture, false imprisonment, and deaths of countless Korean patriots, was assassinated in Seoul on Nov. 2, 1945 (reported by newly liberated Keijo Nippo) (link)
- Voice of America Korean Broadcast - first sent by shortwave from Washington, D.C. on June 13, 1942, with more regular Korean programming beginning from San Francisco on August 29, 1942 (Encyclopedia of Korean Culture link)
- Secret Shortwave Listening Incident - an incident in 1942 which Korean broadcasting-station employees secretly listened to shortwave broadcasts from Voice of America and the Korean Provisional Government in Chongqing, then passed along war news - around 300 broadcasting personnel and civilians were arrested and 75 were convicted (Encyclopedia of Korean Culture - link)
