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History of the manufacturer  

Unitra DIORA - Radiowerk Dzierzoniow,

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Name: Unitra DIORA - Radiowerk Dzierzoniow,    (PL)  
Abbreviation: unitradior

Radiowerk Dzierzoniow, ul. Swidnicka 38 (former Reichenbach, Silesia), Poland. Only later this establishment received the name DIORA. See remark.

After WW2 improved "Philettas" (former Philips model produced there until 1945) were manufactured. The refinement embraced larger speakers and enlarged bakelite cases as well as reduced mains hum and later even wooden cabinets.

These Philetta successors were named "PIONIER"(mainly with U..21 loctal tubes for AC/DC) and "MAZUR"(E type tubes for AC).

Licensing agreements from AGA (Sweden) made use of AGA components possible (e.g.IF filters) for these models, and complete production of other (AGA) models as well.

Pionier and Mazur are considered the most popular radios of polish production and they used to be in high repute for their performance, being superior to their predecessors.

There might have been even another name, but after WW2 in Poland all the factories had been more or less anonymous, only identified by a code number.

Some models:
Country Year Name 1st Tube Notes
PL  90 Śnieżka 3 R311   Thias radio has both CCIR and OIRT FM bands 
PL  85 Faust 205S   Only difference from Faust 206S is in diode field indicator. 
PL  79 Merkury HiFi DSH-303 [Hungarian Export OIRT] BF314  Der Stereoempfänger Merkury DSH-303 enthält 29 Transistoren und 6 ICs. Die Endstufe ist m... 
PL  79 Merkury Hi-Fi DSH-304 [CCIR] BF314  Der Stereoempfänger Merkury DSH-304 enthält 29 Transistoren und 6 ICs. Die Endstufe ist m... 
PL  70 Ballada 24502 ECH81   
PL  60 Calypso 6282 [with EM80] ECC85  OIRT-FM range 64.5 - 73 MHz. 
PL  75 Amor Stereo DSP-102 [CCIR]   Stereo receivers, two external loudspeakers, CCIR FM range, built in ferrite antena, simil... 
PL  90 RE331   This receiver has both FM bands - OIRT and CCIR 
PL  58 Polonez II (2) 6266 ECH21   
PL  74 Ślęża DMT-311 25610    
PL  65 Rumba 21803 ECC85   
PL  75 Maraton PMP201    


Further details for this manufacturer by the members (rmfiorg):


Forum contributions about this manufacturer/brand
Unitra DIORA - Radiowerk Dzierzoniow,
Threads: 1 | Posts: 4
Hits: 6370     Replies: 3
Pionier ZPR - Czecoslovakia 1955
Oriol Sierra

I've recently purchased an old radio in Poland, manufactured by Z.P.R. PIONIER
in Czecoslowakia in 1955 (mod. Pionier-Czecoslovakia 1955). The photo is below.

I am currently restoring it and I am looking for information about the
history of this company (that I think was a subsidiary of Philips) and
if possible, technical information about this model. Could you maybe
help me to find out where can I find this information?


Dirk Becker
  2 I found some information by googling "Pioner U2". U2 is afaik the type name of the set. I repaired one some years ago for a friend of mine. Attached to this answer you find some alignment information which I wrote down, when I was repairing the radio. Perhaps it's a bit helpful for you, even it's in german.


P.S.: some links (the second link contains a schematic):


Henryk Fidos

Presented radio "Pionier" has been produced in Poland in Z.P.R. - Zaklady Przemyslu Radiowego (it means - Factory of Radio Industry) - later "Diora", in Dzierzoniow (Silesia). Not in Czechoslovakia. There were different models of above radio in different housings - wooden or bakelite. I have six different in my collection.The model in the same housing with power transformer was called "Mazur". 

- Henryk

Eilert Menke


please take a look here:

Regards, E.M.

Unitra DIORA - Radiowerk Dzierzoniow,
End of forum contributions about this manufacturer/brand