Rare polish radio – produced only in 1939 with additional automatic motorised tunning to 12 programmed positions and with 4 step choice of selectivity granting extention of acoustic frequencies range depending on choosen selectivity. Serviced by author since 1965 today is in it’s normal reception condition according to data. Tube EAB1 due to unproper operation replaced with EABC 80. EM 1 due to weak picture replaced with EM 4. Some faulty capacitors and resistors replaced with same but not original types.
Power : 3 watts max
Ranges : LW – 700m – 2000 m
MW – 200m – 580 m
SW – 13m – 50 m
Tubes: AZ1, EK3, EF9, EAB1, EF6, EL3, EM 1
Speaker: One widerange 19 cm diameter
Tunning indicator: steel linkage with bronze pointer
Tunning indicator: electron tube
Selctivity: 14 kHz, 11 kHz, 9 kHz, 7 kHz.
Sensitivity: according do found in internet information 5uV
Inputs: El. Gramophone
Outputs: Auxilirary speaker with transformer.
Voltages: 100Vac – 240 Vac
Tone controll – Linear high cut and selector to „Speech” and „Music” changing feedback from speaker coil to preamplifier
Shop price at time of sell – 780 Polish złotych – about 7 monthly weges
Actually due to lack of conditions for areal radio operates only with „grounding” antenna. With this conditins in the evening receives middle waves strong european stations like Praha, Budapest, Bucarest, Sweden. On long waves only Warsaw i Progrmm is heard. In short waves it is world range reception.
Presented below schematic diagramm is not a producer document but a result of record to „as seen” – not 100% may be according to factory diagram but author has no knowledge about this differences. His intention was to regain original circuitry and to present it.
Click drawing to see details and magnify.
Update 13 march 2016 – schematic diagram replaced with newer version – few faults rectified in input circuitry, visual arrangement improved and changed graphic format to make it more readable
Update 28 October 2016 schematic diagram replaced with newer version – another few faults rectified in input circuitry, visual arrangement improved
INSIDE THE ELECTRIC AUTOMATIC – click photos and magnify.
Front view – visible is octal type tube typoe EABC80 modified to meet original EAB1 socket. Existing original EAB1 although still working was malfunctioning
Programmed device. Each hand positioned slider fixed fo round rail serves one of 12 selected by owner positions of scale
Rear wiev -author managed to obtain all original type tubes – in 1945 radio was already fixed with two newer and not original type tubes – ECH4N instead of EK3 qand EBL21 instead of EL3. There were also some changes made to original circuitry concept made by unknown workshop(s?). After deep search author managed to bring back the original idea
Automatic device – panel of programmed push buttons. Visible electromagnet provides selfsupport to mechanical bar blocking the button in down position untill the desired position is met. With this moment motor stops, motor shaft moves axialy back to nonactive position by contact spring force, electromagnet coil voltage is off, bar is up and button is returned to up position.
Rear view of speaker. Most radios in this years had speakers with electromagnet. One of reasons was problem to obtain powerfull magnet field from solid magnets. Presented magnet was imported to Poland from England. Also the speaker diaphragm was imported from England.
Visible is scale driving motor with speed gear on other side . In center attached spring contacts – pair for switching supply to electromagnet and pair for grounding audio signal during time of automatic movement
Behind reconstructed by author steel plate in round cuts visible are 3 tunning air capacitors for two serial input filters and one for oscillator.
Out of case general view