Radio Laboratory in Bandung
in the first half of the 1930s
The integral reproduction of this photographic album originate also from late Bob Grevenstuk
Please notice: this page is providing quite high resolution pictures and one should operate a fast internet access!
Copying is permitted for non commercial purposes only, and proper reference should be given at any times.
Radioinstellingen op Java
Monument te Kootwijk (1939)
Gerichte Antenne ple begin 1930
Original text at the back of this photo: gezicht antenne lab. begin 1930 ple
'ple' stood for the call-sign of one of the long distance wireless stations
At the back of this photo: 5-11-1937
2de Werkplaats Radiolaboratorium Tegallega
At its back: Nieuwe werkplaats radio lab. beging Mei 1933
In those days, Klaas Dijkstra was heading the mechanical workshops of the Radio Laboratory in Bandung (Bandoeng). Due to an accident during this tropical leave in 1935 in Switzerland, he was handicapped since, and became responsible for the administration of materials and spare parts of the Radio Laboratory. Actually, he initiated this office.
ane. 1927 (ane means the transmitter call-sign)
At its back: Oude ane 1927 (old ane 1927)
At its back: Oude ane 1927
B.B. stood for: Binnenlands Bestuur.
Verschillende ontvangtoestellen 1927
pmy Preanger Hotel 1929. 250 watt λ = 58 m
The room window at the far right-hand site.
Why they used this un-common facility I don't know.
In July 1978, together with my wife Karin, we stayed for a single night in the Preanger Hotel in Bandung. It was a big colonial style building. The sealing of the rooms, then, from memory, were at least 4 m high. It had a big garden. We only slapped a single night, because the next day we moved to the house of late Rob Kain. Who then lived at Jalan Sukajadi 200 or 250?? We stayed several times there. Rob (YB1KW) and his XYL Erlien were most kind people. We kept in touch until she died in 2011, being far in her 90s.
Carrying no caption
but from Klaas Dijkstra's book Radio Malabar we know that it concerns the prototype of the 80 kW transmitter
Which worked fine in this open environment, but caused tremendous setbacks when it was finally constructed (build-in) a full metal housing. Entirely new techniques had to be 'invented' as to neutralise the self-oscillations of the PA stage. The anode - grid capacitance was rather high and coping with it at frequencies of, say, 15 MHz or even higher the neutralising capacitances were becoming impractical. The circular arrangement in front is part of the neutralisation circuit, but before new techniques had to be developed.
Jr. was used as to express that this was operational version. Sr. was thus the experimental type. Often running for a while having the same call-sign or station designation.
1e en 2e trap pmb. 1930
At its back: eerste en tweede trap pmb achterkant geopend
3e, 4e en 5e trap pmb. en de modulatorkast met 6 modulator lampen
From Klaas Dijkstra's book we know, that the task (challenge) once set to him, was to build a 80 kW transmitter having 5 stages only.
Accomplishing eventually this task brought Klaas Dijkstra among some others the (shared) Veder Price of 1931 Albeit, he received the price a bit delayed. Among the price winners was also Klaas Dijkstra's chief director Willem F. Einthoven. Just the one who brought once these albums to Holland. Would he not have done so, we most likely never would have seen these pictures at all!
Hand-written at its back: 3de trap pmb achterkant geopend
At its back: 4de trap pmb
At its back: 5de trap pmb
At its back: modulator kast 6 modulator(lampen, AOB) pmb
Telefoonzender voor scheepsverkeer. Semarang
At its back: Scheeps zender Semarang achter kant
Please notice: Uitgekookt 10-1929, which likely indicates that the transformer oil was heated (cooked) in October 1929. We may assume, that this transmitter was accepted in late 1929 or somewhere in 1930.
At its back: Scheepszender Semarang voor kant
Zenders ple sr. en ple jr. Radio lab. Tegallega begin Mei 1933
Likely: on the left the first version (sr.) for the wireless transmitter link 'ple' adjacent the second version (jr.) also meant for the same station ('ple').
Single sideband multiple ontvanger. Radiolab. 1933
At its back: Single Side band multiple ontvanger radio laboratorium begin mei 1933.
This is a rather exceptional apparatus. The Dutch PTT (both the Dutch and the colonial organisations) commenced the first multi-channel intercontinental SSB telephone links on shortwave. In our collection, we have the Koomans designed Dutch version, most likely the only remaining apparatus of this series. The latter used 4 SSB channels, one for lower and one for upper sideband. Two additional two sidebands were commenced one above the SSB centre frequency and one below it. These latter two channels were operated for telex connections in diversity, as to enhance its reliability; as telex is responding quite sensitive on false data content. These were designated 'telegrafiekanalen' generally. However, in some respect it is known from Klaas Dijkstra's book that the Radio Laboratory in Bandung developed their own version.
Standaard frequentie inrichtingen van R.C.A. en G.R. Kelder Radiolab. 1933
At its back: kelder met standaard frequentie inrichting van R.C.A. en G.R. Radio lab. Tegallega begin Mei 1933
G.R. stands for General Radio.
From Klaas Dijkstra's book, we know that Willem Einthoven, the director of the Radio Laboratory of Bandung purchased these devices when he visited the US on his trip to or from Holland. Dijkstra also remembered that in the beginning they encountered some stability problems. The basement environment was controlled by means of an air-conditioning. A rather rare provision in those colonial days.
I assume, that the GR unit is at the far right-hand side. On the far left-hand side we notice a so-called 'Moeder klok' or 'Master pendulum'. These clocks regularly provide standard second- maybe also hour pulses. These signals could be conveyed by means of telephone links (wire or wireless, or a mixiture) to a wide area. In previous days, I think even into the late 1980s the US time-signals from WWV on 5 and 10 MHz, were widely employed. The limitation of short and long wave signals is the downside of propagation. Limiting its application to < 10-8. But, 10-6 is practically obtainable. Please notice my 2001 paper: Some aspects of precision time measurements, controlled by means of piezo-electric-vibrators, as deployed in Germany, prior to 1950 High precision time measurement is limited by the transit-time of the time-reference-signals in wire systems, such as telephone cables. We know that the velocity of light is just 300,000 km/s; don't wonder that in telephone systems delays of 30 percent is possible, hence, sometimes being 200,000 km/s instead. For high accuracy fanatics - the signal-phase of wireless time signals being also inflicted by the environment surrounding the antenna; think of rain or snow and that like.
Onthulling op 23 September 1939
van het Monument te Kootwyk
ter herinnering van de opening
tussen Nerderland en Nederlandsch-IndiŽ
De Directeur Generaal der P.T.T. Dr. Ir. M.H. Damme spreekt
De Directeur Generaal der P.T.T. aan het woord
Luisterende gasten tydens de rede van de Directeur Generaal
De vertegenwoordiger van het personeel van Kootwijk, de heer Bakker, dankt den Directeur Generaal
(My personal comment AOB. When you look at the stature of the man on the pedestal (Director General Mr. Damme), I get personally the strong impression that: a God is accepting the honour of his subordinate Mr Bakker.)
Het Monument onthuld
Bezichtiging van het monument; de Directeur Generaal in gesprek met architect Mauve
Op 28 Februari 1928 stelden de Nederlandsche en Nederlandsch Indische P.T.T. Diensten de door hen tot stand gebrachte RADIOTELEFOONVERBINDING tusschen Nederland en Nederlandsch-IndiŽ, de eerste in haar soort ter wereld, ter beschikking van het Nederlandsche volk.
Het monument. Voorzyde
H.M De Koningin Moeder wydde de verbinding in te 's Gravenhage in de P.T.T. Studio sprekende met den Landvoogd en diens Gemalin te Batavia.
Het monument. Eťn der zykanten
Het door den tuinarchitect B.C. van den Steenhoven verzorgde plantsoentje, waarin monument en gedenkkei een plaats vonden
Bezichtiging van de gedenkkei; naast de Directeur Generaal de beeldhouwer Titus Leeser, die het inschrift verzorgde
De grote gedenkkei met een kleine bewaker
By Arthur O. Bauer
Please return to, or proceed with: Dutch-Indies PTT main page
To: Dijkstra's Radio-Kootwijk photographs