Type Approval Mark
Beginning of Radio Broadcasting
-Crystal receiver and Battery Operated Tube radio-
1925-28
Before the Broadcasting
Beginning of Broadcasting
Radios at the beginning of Broadcasting
Radio Museum (UPDATED)
NOTICE:
Gothic is latest updates.
Japanese terms or company
names that is untranslatable are shown in spelled in Italics.
When not mentioned specially, all prices are original retail price.
Japan has a long history of researching wireless Communications as well
as its home production.
Three years after the experiment on yield of current by Herz (1886), Hantaro
Nagaoka made public experiment in spark discharge at The University of Tokyo(1889).
Just after Marconi's wireless Communications in 1887, research started
for practical use by Electrotechnical Laboratory in Japan.
And in 1899 began home products of wireless equipments. Thus wireless equipments
realized excellent results at the Battle of the Japan Sea in 1914.
After the WW I, wireless were used very often, not only for military use
but also for marine use.
In 1914, with regard to this situation, the Wireless Law and the Reguration
for Private Wireless Telegraph were enacted.
In 1920, KDKA Station in U.S.A. started world first broadcasting.
Also in Japan research on broadcasting became much popular, and various
experiments were extensively carried on.
Consequentry many technical books, periodicals and magazines were published.
By confusion of the Kanto Earthquake Disaster in 1923, information routes
were cut off.
But ships anchored in Tokyo Bay gave the most effective results communicating
by wireless.
Consequently public opinion were aroused for realization of broadcasting.
In the next year after the Earthquake, applications for establishing broadcasting
station were estimated to reach 64 throughout the land.
But Japanese government set limits and sanctioned the establishment of
broadcasting stations running by juridical person for the public benefit
in three great cities, Tokyo, Osaka, Nagoya.
In 1924, Tokyo Broadcasting Station (JOAK), in 1925 Osaka Broadcasting
Station (JOBK) and Nagoya Broadcasting Station (JOCK) were established.
they were authorized in the form of corporate juridical persons.
On 22 March, 1925, the Tokyo Broadcasting Station(JOAK) started temporary
broadcating with approximately 220W of power at Shibaura, Tokyo, which
was the beginning of Japanese history of radio broadcasting. Only 5 years
behind the world first broadcast in U.S.A.
The two other stations also commenced their activities later in the same
year.
Although the number of listeners of was no more than 5,455 at that time,
it jumped to 390,000 by 1926.
In view of the necessity of expanding the radio networks on a systematic
basis, thereby creating a more uniform service area for multipying the
number of listners, the Nippon Hoso Kyokai (the Broadcasting Corporation
of Japan) was organized by amalgamating these corporations in August 1926.
With the establishment of the corporation, headquaters were astablished
in Tokyo, and branches in the Kanto, Kansai, and Tokai districts within
the sphare of influence of these 3 broadcasting stations.
Radios at the beginning of broadcasting
Type Approval Mark
Under the ordinance the Regulation for Private Wireless Telephone promulgated
in 1923 just before the beginning of broadcasting, radios were admitted
as obtained sanction from the Communications Ministry.
Technical standard was set on the basis of the ordinance "The Regulation
for Electrical Appliance", Article 4 of the Communications Ministry
issued in 1916, and it is decided that the wave length must be confined
within 200-250m or 250-400m, besides radio waves must be without generation
from antenna.
Whoever passed examination acquired the model examination by the Electrical
Laboratory of the Communications Ministry.
Manufacturer could indicate passing number as well as type approval stamp
(created in 1924).
As for approved receivers, wave-length selector was required, and besides
generation of radio wave was permitted.
Thus, regenerative detector could not be used, the sensitivity was low,
therefore expensive.
Due to the unexpectedlly large number of listners who applied for licences
with the commencement of the business, the demands of listners surpassed
by far the supply of approved receivers. In addition, foreign made receivers
were excelent and comparatively cheaper than those made in Japan, and moreover,
a good many radio fans constructed their own receovers at home.
But in reality, lots of imported and hand-made radios not always following
such ruled ware used.
On 18 April, 1925 just after the beginning of broadcasting, Ordinance
No.23 of the Communications Ministry was issued, which abolished selector
of wave length and limited wave length less than 400m.
In addition to it, permission for listening was given to non approved radios.
Accordingly, type approval system became nominal. After Ordinance No.71
of October 1925 now on, no more than examination was carried on.
Through 1924 into 1925 type approval was given to 64 varieties of radios
and parts, of which from No.2 to No.71 (No. 1,6,1,12,13,35,36 missing)
are in existence.
Manufacturers of communicating equipment such as Annaka and Shibaura which had produced lots of approved receivers withdrew from radio sets production several years after the beginning of broadcasting.
70% of Japanese radios at that time were crystal type listening worth
receivers.
Battery operated tube radios using loud speaker system were not only expensive
but also had to equip three types (A, B, C) of battery, especially by using
Lead-acid battery for "A" lighting filament, the work required
much time to charging. Consequently not of public use.
Japan introduced technique and appliances of radios from U.S.A.
At first triode tube UV-201 ware used. Later, 201-A type with filament
current reduced by half or power economized type 199 were used.
As the result of that, A type battery could be changed from Lead-acid battery
to dry battery.
Therefore, since about 1924 much of radio sets have contained batteries
inside.
Early Crystal Radio with Catwhisker (U.S.A. unknown mfr. 1920?)
Homebuilt Crystal Radio with wooden Cabinet (U.S.A. unknown mfr. early 1920s)
TUNER + Crystal Detector (U.S.A. unknown mfr. 1920?)
Westinghouse Aeriola Jr. (Type RE) Westinghouse Electric & Manufacturing Company (U.S.A. 1921-22)
Japanese Crystal Radio with Fixed Detector (Made in Japan 192７?)
Japanese Crystal Radio with Fixed Detector (Made in Japan 1929?)
Japanese Crystal Radio with Fixed Detector (Made in Japan 1929?)
Radios Made in U.S.A.
Single Tube Receiver (U.S.A. 1922?)
Westinghouse Model RC 3-tubes Regenarative Receiver Westinghouse Electric & Manufacturing
Co. (U.S.A.) 1922年 $130
Freed-Eisemann NR-5 Neutrodyne Receiver Freed-Eisemann Radio Corp. (1923) $150
Freed-Eisemann FE-50 Horn Speaker Freed-Eisemann Radio Corp. (1924? )
Crosley Model 51 Regenerative Receiver The Crosley Radio Corporation (1924) $18.50
Crosley TRIRDYN REGULAR Type No.1121 The Crosley Radio Corporation (1925) $50
Crosley Super Trirdyn Special The Crosley Radio Corporation (1925) $60
Grebe Synchrophase MU1 Neutrodyne Receiver A.H. Grebe & Co.,Inc. ( 1925) $155
Radiola III Radio Corpolation of America : RCA (1924)
Radiola III-A Radio Corpolation of America : RCA (1924)
Radiola Superheterodyne AR-812 Radio Corpolation of America : RCA (1924)
Radiola 25 (AR-919) Superheterodyne Radio Corpolation of America : RCA (1925-27) $165
Radiola 20 AR-918 TRF Receiver Radio Corpolation of America : RCA (1925-27) $115
Radiola Loud Speaker Model 100 (UZ-915) Radio Corpolation of America : RCA (1925) $39
Magnavox 25型 TRF set Built in Horn Speaker The Magnavox Cmpany (1925) $165
Atwater Kent Model 30 TRF Receiver Atwater Kent Manufacturing Co. (1926-27) $105
Radios Made in Japan
NEC Head Set (Nippon Electric Co., 1924) Type Approval No.2 JPY 14.00
Cymofone A-2 2-tubes receiver (Tokyo Electric 1925) Type Approva No.9-2
Annaka AR-82 Head set (Annaka Electric works 1925) Type Approva No.17
4 tubes Regenerative Receiver (unknown 1925?)
AI-PHONE Type III (Modified AC set) (Aichi Tokei Kaisha 1925?, 1930?: 1st modified, 1935: 2nd Modified) JPY
150.00(less tubes)
JUNOLA 6D Superheterodyne Receiver (Shibaura Engineering Works 1927)
2 tubes Regenerative Receiver (unknown 1927?)
Browning Drake type Receiver (unknown 1928?)
Halodyne Neutrodyne Receiver (KANEMAN ELECTRIC Co. 1929)
Crystal receiver
Early Crystal Radio with Cat-whisker (U.S.A. unknown mfr. 1920?)
This is early 1920's primitive crystal radio manufactured and used in U.S.A.
Station was selected by the slider of tuning coil.
Detector is "catwhisker" type (detector arm and spring is lost)
(Collection No.11535)
Homebuilt Crystal Radio with wooden Cabinet (U.S.A. unknown mfr. early 1920's)
This is 1920's crystal radio with wooden cabinet manufactured and used
in U.S.A.
Station was selected by the tap of solenoide coil.
Detector is "catwhisker" type (detector arm and spring is lost
and installed Ge diode later)
(Collection No.11533)
TUNER + Crystal Detector (U.S.A. unknown mfr. 1920?)
This is early 1920s crystal receiver. Detector was connected to the terminal
of tuner.
The plate indicated the condition of license from Marconi Company was attached to inside cabinet.
(Collection No.11805)
Westinghouse Aeriola Jr.(Type RE) Westinghouse Electric & Manufacturing Company (U.S.A. 1921-22) $25
Crystal Radio with Catwhisker, bestseller just after the beginning of broadcasting.
In 1922 the brand name was standardized to Radiola of RCA. Thus became
Radiola Junior.
(Collection No.11720)
Japanese Crystal Radio with Fixed Detector Home Brew (192７?)
The simplest type crystal radio used in Japan just after the beginning
of broadcasting.
In use, fixed detector was installed to holder on the front panel.
Without variable capacitor. Stations were selected only by tap of antenna
coil.
The construction of cabinet is nasty. This set may be constructed by amature.
(Collection No.11482)
Japanese Crystal Radio with Fixed Detector Home Brew (1928?)
The simplest type crystal radio used in Japan just after the beginning
of broadcasting.
In use, fixed detector was installed to holder on the front panel.
Without variable capacitor. Stations were selected only by tap of spider
coil.
(Collection No.11240)
Japanese Crystal Radio with Fixed Detector mfr: unknown (1929?)
This is a typical crystal radio used in Japan just after the beginning of broadcasting.
In use, fixed detector was installed to holder on the front panel.
Stations were selected by variable capacitor and tap of spider coil.
Such radio was manufactured until late 1930's.
(Collection No.11502)
Battery Operated Tube radio
Single Tube Receiver (U.S.A. unknown 1922?)
TUBES one-UV-201
Most simplest one-tube set.
Tuning circuit using variable capacitor and large solenoid coil was connected
to grid detector.
The 4 small holes on the front panel was prepared to check filament .
(Collection No.11335)
Westinghouse Model RC 3-tubes Regenarative Receiver Westinghouse Electric & Manufacturing Co. U.S.A. 1922年 $130
TUBES: 3- UV-200/UV-201/UV-201-A/WD-12 (RCA Radiotron)
Westinghouse Model RC was very early radio set produced in late 1921.
The RC was combined the RA tuner and RD detector amplifier in a single cabinet.
The frequency range of this set was 180-700m(428-1700kHz).
This range is almost equaled to B.C. band. However, it was called “short
wave” at that time.
(Collection No.11806)
Freed-Eisemann NR-5 Neutrodyne Receiver (1923 U.S.A.) $150
Freed-Eisemann FE-50 Horn Speaker Freed-Eisemann Radio Corp. (1924?)
TUBES: 5- UV-201-A
Typical of early Neutrodyne receiver. This type was used in 1924 for the
experiment receiving radio wave from KGO station (U.S.A.) in Japan successfully.
(Collection No.11422/10044)
Crosley Model 51 Regenerative Receiver The Crosley Radio Corporation (1924) $18.50
TUBES: 2- UV-201A
Crosley’s best seller low cost set. Regenerative detector + audio stage
could drive a head set.
To reduce cost, unique hinged variable capacitor was used.
This is later model after July 1924. Model 51 was sold 197,000 sets.
To drive horn speaker, Model 51A amplifier was available.
(Collection No.11804)
Crosley TRIRDYN REGULAR Type No.1121 Regenerative 3-tubes Reflex Receiver The Crosley Radio Corporation (1925) $50
TUBES: 3- UV-201A
The TRYADYNE set was adopted adopting reflex-system and regenerative detector.
This circuit realized high performance with reduced tubes.
This set was produced as Triadyne model 3-R-3 in 1924 ($65).
In 1925, High grade model “The Triadyne Special “ was added.
This model was changed the name into “Triadyne Regular”.
The lay-out of front panel was different from model 3-R-3. Price was reduced $50.
Large numbers of “TRYADYN” sets were imported to Japan at that time.
The low-cost circuit were imitated by Japanese makers and amateurs and made in large numbers.
(Collection No.11719)
Crosley Super Trirdyn Special The Crosley Radio Corporation (1925) $60
TUBES 3- UV-201A
In September 1925, TRIADYNE series was changed into SUPER TRIADYNE.
This set is high-end model.
Cabinet was changed into gorgeous design, however, circuit hardly changed.
Manufacturer was advertised that “ Better Result from 3 Tubes Than from 5”.
Chassis was very small. The cabinet has large space to installing dry cells.
(Collection No.11464)
Grebe Synchrophase MU1 Neutrodyne Receicver A.H. Grebe & Co.,Inc. (U.S.A. 1925) $155
TUBES: 5- UV-201A
アメリカ、グレーべ(発音はグリービーとなる)社の高級受信機。
ニュートロダイン方式の高周波2段低周波2段の5球受信機で、真空管はUV-201Aを使用している。
同社のラジオは、ローロスバリコンを垂直に配置するレイアウトに特徴があり、この機種は3つのバリコンがチェーンで連結され、連動するようになっている。
コイルには、リーケージ低減を狙ったビノキュラー(Binocular：双眼鏡の意)コイルが使われている。
個性的でデザイン、レイアウトともに美しいセットである。
(Collection No.11465)
Radiola III (1924 U.S.A.) Radio Corpolation of America : RCA $35.00
TUBES: 2- WD-11
小型真空管WD-11を2本使用するシンプルな受信機。アメリカでは$35と比較的低価格で発売された。バリコンではなく、コイルの角度を調整するバリオカプラで同調する。バンドは中波帯とほぼ等しい220-50mである。スピーカーを鳴らすには別売の2球式アンプ($30)を接続する必要がある。アンプ部を内蔵した4球のIII-A型($65)もあった。このシリーズはRCAのボトムエンドを構成し、50万台近く生産されたという。
本機は底板が失われている。実際には右の写真のように内部を見ることはできない。
Bottom plate was missing.
(Collection No.11280)
Radiola III-A (1924 U.S.A.) Radio Corpolation of America : RCA $65.00
TUBES: 4- WD-11
ラジオラIII型に、2球のアンプ部を追加してひとつのキャビネットに収めたモデル。スピーカを直接鳴らすことができる。高周波部はIII型とまったく同じである。真空管は、三極管WD-11を4本使用する。電源はA電池が4-6V、B電池が90V、C電池4.5Vの3種類の電池を必要とする。本体は小型だが電池、スピーカ、アンテナ、アースを含めたシステムはかなり大掛かりなものになる。
Tubes was missing.
(Collection No.11460)
Radiola Super Heterodyne AR-812 (1924 U.S.A.) Radio Corpolation of America : RCA
Chassis can be pulled off easily Caution plate inside the cabinet
TUBES 6- UV-199, Super Heterodyne (Second Hermonics)
Radiola Superheterodyne was imported by Tokyo Electric Co., obtained license
of G.E..
It was more expensive than a house, Price was JPY 850 that is equaled to
the price of small house !!
Only a few rich people could afford to use.
(Collection No.11408)
Radiola 25 (AR-919) Super Heterodyne Radio Corpolation of America : RCA (1925-27) $165
TUBES: 5- UX-199 - UX-120, Super Heterodyne (Second Hermonics)
AR-812に続く、2世代目のラジオラ・スーパーヘテロダイン。回路はAR-812と同じセカンド・ハーモニクスを使うオートダイン式コンバータの6球スーパーである。旧来の”Catacomb"に回路が納められた構造は同じだが、ソケットがUVからUXに変更されている。同調と局発のダイヤルはクラッチ付のカップリングで結合され、簡単に連動と独立した操作を行うことができた。このダイヤルをRCAでは”Thumbwheel
Dia”と呼んだ。ドラムには放送局のコールサインを鉛筆で記入することができた。このセットは、専用のループアンテナを天板中央のコネクタに接続して使用する。バッテリーをキャビネット左右に内蔵するため、幅90cm近い巨大なラジオである。スピーカは古いホーン型のUZ-1325の他に、同時に用意されたコーンスピーカ、モデル100,102,104から選ぶことができた。この上のクラスには8球の28型があった。この25型は9万4000台あまり生産されたほか、同じ回路で構造が異なるシャーシが電蓄組込み用に生産された。
(Collection No.11721)
Radiola 20 AR-918 TRF Receiver Radio Corpolation of America : RCA (U.S.A. 1925-27) $115
TUBES: 4- UX-199 - UX-120, TRF
RCAのローエンドモデルとなるTRF受信機。UX-199を4本、高周波2段と検波、低周波増幅の初段を構成し、UX-120でスピーカを駆動する。キャビネットのデザインは上級機の25,28型スーパーと共通である。左に選局、右にバリオカプラーによる再生用のドラム型ダイヤルにまとめられた操作系は扱いやすかった。シングルコントロールとするためバリコンはカップリングで連動し、バリコンは周波数直線型であった。ドラムには放送局のコールサインを鉛筆で記入することができた。正面パネルのツマミは各高周波段微調用のバリコン2個と、フィラメント調整用のレオスタット2個である。右端のジャックは、フィラメントチェック用の電圧計をつなぐためのものである。本機は13万台以上生産されたという。
(Collection No.11717)
Radiola Loud Speaker Model 100 (UZ-915) Radio Corpolation of America : RCA (1924) $39
Radiola 20、25と組み合わせられるスピーカ。RCA初のマグネチック・コーンスピーカである。金属性キャビネットに12インチのユニットを収めている。"Electrical TOne Clarifier" と呼ぶフィルタを備えている。このスピーカは、1927年に小型の100-A型にモデルチェンジされた。
(Collection No.10045)
Magnavox 25型 The Magnavox Cmpany (1925) $145
向かって左が出力端子、右がA電池をつなぐ端子。
Chassis(Left) Name Plate(Right)
TUBES: 5- 201-A
ホーンスピーカの老舗、マグナボックスのラジオ。高周波2段低周波2段の5球受信機である。真空管は201-Aを使用する。ただし、同社から、防振型の特殊な同等管が発売されていた。後に一般的になるギャング型3連バリコンを使用することで完全なシングルコントロールを実現しているのが特徴である。また、バッテリーケーブルとシャーシの接続は、丸型の多ピンコネクタが使用されている。このため、シャーシが小型にまとめられ、当時の電池式受信機とは一線を画す、後の世代の受信機に近いレイアウトとなっている。シャーシは抽斗状の木製ケースに収められている。このD型シャーシは同社の他機種と共通化され、改良時に簡単に入れ替えられるように考えられていた。シャーシ部を独立した筺体に収めた構造は振動に強く、当時としては珍しくホーンスピーカを同じキャビネットに内蔵している。A電池は外部から接続し、B電池はスピーカ部に収納する。
(Collection No.11722)
NEC Head Set (Nippon Electric Co., Ltd. 1924) Type Approval No.2 JPY 14.00
This head phones was the first approved apparatus manufactured by NEC.
Approved number was “2”. No.1 was not used.
At that time approval was not only mandated to radio set but also parts and accessories.
(from private collection)
Cymofone A-2 2-tube Receiver (Tokyo Electric 1925) Type Approval No.9-2
Annaka Model AR-82 Head Phones (Annaka Electric Works 1925) Type Approval No.17
TUBES: 2- UV-199
Cymofone A-2 was type approved 2 tubes receiver manufactured by Tokyo Electric
Co., licensed from G.E.
This set used Cymotron UV-199 licensed by G.E..
Original chassis and handle were missing. Holes inside cabinet was unoriginal.
Annaka was the pioneer of Japanese wireless.
They made many type approved radio and parts.
This appliance exist only one unit.
(Collection No.11174, 10050)
4tube Regenerative Receiver (unknown 1925?)
TUBES 4- UV-201A
Receiver made in Japan at the beginning of broadcasting.
Build quality was good and used high quality Japanese parts and imported
parts.
(Collection No.11212)
AI-PHONE Type III (Modified AC set) (Aichi Tokei Kaisha 1925?, 1930?: 1st modified, 1935: 2nd Modified) JPY
150.00(less tubes)
TUBES: 227-26B-26B-12F (after last modification, original is unknown)
A part of the cabinet of battery set.No Original parts inside. Trade
mark on the top cover.
Original front panel (from catalogue)
Added cabinet for AC set in 1930 Additional
cabinet was connected to original cabinet.
In 1935, Chassis was renewed.
Aichi Tokei Kaisha (now: Aichi Tokei Denki Co., Ltd.) Was founded as a clock manufacturing company in Nagoya in 1898.
Aichi Tokei was one of the founders of Nagoya Broadcasting Corporation.
They started manufacturing radio set from 1925.
However, type approval system became nominal at the end of 1925. The price of radio set was decreased rapidly. Aichi Tokei withdrew from radio sets production several years after the beginning of broadcasting.
The original of this set was 2 tubes battry operated regenerative radio
with internal speaker.
This radio set was modified twice.
First, About in 1930, original chassis and speaker was dismantled.
New hand crafted cabinet made to match the old cabinet.
New AC set built in new cabinet. And bottom plate of old cabinet was cut off.
New and old cabinet connected by screws.
The new AC set had 2 tuning circuit to listen easily 2 stations.
This circuit was not convenient.
Second modification did in 1935(probably).
All old parts except dial and knob was dismantled.
Complete chassis manufactured by Mitaka Denki K.K. was installed.
Circuit was typically 4 tube regenerative (0-V-2)
The lin up of tubes were 227-26B-26B-12F.
This set was modified every 5 years to catch up the progress of technology.
(Collection No.11830)
JUNOLA 6D Super Heterodyne (Shibaura Engineering Works 1927)
TUBES 6- UV-199
Japanese production of AR-812 made by Shibaura Engineering Works (now Toshiba Ltd.) with license from
GE..
The construction and dial-system were the same however layout was different
and width was a little narrows.
As automobile has not been popularized at that time in Japan.
Large-sized portable radios had no meaning. Thus, the had no handles.
The selling price was as half as that of RCA product, however it's very
high price in Japan.
The left hand grill and 4 vertical cross were missing.
(Collection No.11607)
Atwater Kent Model 30 Atwater Kent Manufacturing Co. (U.S.A. 1926-27) $105
TUBES: 6- UX-201-A, TRF
アメリカの大手メーカ、アットウォーターケントのストレート受信機。高周波3段低周波2段の6球で、真空管はUX201-Aを使用している。3極管しかない時代、ラジオの感度を上げるには高周波増幅の段数を増やすしかなかった。高周波の多段増幅を安定にする方法に、ハゼルチンのニュートロダイン法がある。アットウォーターケントは、この特許を避けるために、補償コンデンサを使うニュートロダインに対して、格段のグリッドに直列抵抗を入れる方法をとっている。当時は2連、3連というバリコンがなかったので、ラジオの操作は非常に難しかった。同社は、バリコンを金属ベルトで連結することでシングル・コントロールを実現した。また、同社製品は非常にコンパクトにまとめられているのが特徴である。この機種でも、部品はぎりぎりのレイアウトにまとめられ、干渉を防ぐためにコイルの角度を90度づつ変えている。モデル30は1年で10万台を超えるベストセラーとなったが、他社からもシングル・コントロールの製品が発売されたため、発売後2ヶ月で$86に値下げされた。
(Collection No.11466)
2-tube Regenerative Receiver (unknown 1927)
TUBES: UX-301A(TOYO)(equivalent from 201A）, Regenerative
Small Japanese receiver with grid detector and single stage amplifier.
Trade mark “M” indicated on the front panel. And serial Number “C2714” indicated inside of cabinet.
This set maybe manufactured by set maker.
Regenerative controlled by vario-coupler.
This set used in China.
Tickler control mechanism was broken.
(Collection No.11409)
Browning-Drake type Receiver unknown 1928?
Nanaola Flower-Vox horn Speaker Nanao Radio 1930
TUBES: 5- UX-201A
With Browning-Drake type type receiver big maker did not dealt because
of anxiety sbout patent problem.
This receiver seems to be hand-made by a small maker or an amateur.
Speaker is Rola type Japanese horn speaker made by Nanao Radio. It was
named "Flower Vox".
(Collection No.11612)
Halodyne Neutrodyne Receiver (KANEMAN ELECTRIC Co. 1929)
TUBES: 201A-201A-201A-112A-112A
Japanese Small manufacturer’s Neutrodyne receiver using 3 201A for RF stage and 2 112A for AF stage (Japanese “Cymotron” bulbs .
This set remained at an old family in Nagano pref.
It is complete set include horn speaker (“Omar” brand, made in Japan) and
A/B/C batteries (“A”: Yuasa Model RA-2 6V, “B”: GS model BK-80 90/45/22/5V,
“C”: unknown dry cell 4.5V)
Condition is very good and all parts is original.
Old memo was attached on the cabinet.
The memo indicated call sign of Japanese high power stations and their positions of dial.
The longest distance from Nagano to the station was 1,000 km. !
Antenna and ground wire was also remained.
Antenna wire equipped connector for light bulb socket.
From 1930, only 1 year after manufactured this set, radio was changed from
battery to AC set.
It seemed that this radio was replaced to new AC set and stored warehouse
for a long time.
(Collection No.11825)