radiomuseum.org
Please click your language flag. Bitte Sprachflagge klicken.

396-W Type 1939

396-W; Minerva-Radio (ID = 48711) Radio
 
396-W; Minerva-Radio (ID = 266809) Radio
 
396-W; Minerva-Radio (ID = 108849) Radio
 
396-W; Minerva-Radio (ID = 350989) Radio
396-W; Minerva-Radio (ID = 1612530) Radio 396-W; Minerva-Radio (ID = 211549) Radio
396-W; Minerva-Radio (ID = 211551) Radio 396-W; Minerva-Radio (ID = 211550) Radio
396-W; Minerva-Radio (ID = 142642) Radio 396-W; Minerva-Radio (ID = 211552) Radio
396-W; Minerva-Radio (ID = 228553) Radio 396-W; Minerva-Radio (ID = 228554) Radio
396-W; Minerva-Radio (ID = 228555) Radio 396-W; Minerva-Radio (ID = 878203) Radio
Use red slider bar for more.
396-W; Minerva-Radio (ID = 1612530) Radio
Minerva-Radio: 396-W [Radio] ID = 1612530 933x743
Select picture or schematic to display from thumbnails on the right and click for download.
For model 396-W Type 1939, Minerva-Radio (Radiola-Radioapparate und Bestandteile W. Wohleber & Co) ; Wien
 
Country:  Austria
Manufacturer / Brand:  Minerva-Radio (Radiola-Radioapparate und Bestandteile W. Wohleber & Co) ; Wien
Year: 1938/1939 Category: Broadcast Receiver - or past WW2 Tuner
Valves / Tubes 6: ECH11 EBF11 EL11 AZ11 EM1 EFM11
Main principle Superheterodyne (common); ZF/IF 128,5 kHz
Tuned circuits 7 AM circuit(s)
Wave bands Broadcast, Long Wave and 2 x Short Wave.
Details
Power type and voltage Alternating Current supply (AC) / 110, 130, 155, 220, 240 Volt
Loudspeaker Permanent Magnet Dynamic (PDyn) Loudspeaker (moving coil) / Ø 22 cm = 8.7 inch
Power out
from Radiomuseum.org Model: 396-W [Type 1939] - Minerva-Radio Radiola-
Material Wooden case
Shape Tablemodel, low profile (big size).
Dimensions (WHD) 520 x 355 x 257 mm / 20.5 x 14 x 10.1 inch
Notes Minerva 396W hat 2 Mag.Augen als NF-Pentode! Übrigens: Wir schreiben nur je EIN MAL auch die Firma in den Modell-Namen, also nach 396W suchen, nicht Minerva 396W etc.
Price in first year of sale 295.00 RM
External source of data E. Erb 3-907007-36-0
Source of data Handbuch WDRG 1938 / Radiokatalog Band 2, Ernst Erb
Circuit diagram reference Lange+Schenk+FS-Röhrenbestückung
Mentioned in -- Original prospect or advert
Literature/Schematics (1) -- Original-techn. papers.


All listed radios etc. from Minerva-Radio (Radiola-Radioapparate und Bestandteile W. Wohleber & Co) ; Wien
Here you find 627 models, 557 with images and 443 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.



 


Forum contributions about this model
Minerva-Radio: 396-W
Threads: 1 | Posts: 6
Hits: 1194     Replies: 5
minerva: Why two magic eyes?
Piotr Jachymczyk
05.Jun.16
  1

Hello, 

recentyl I bought this radio and I wonder - why there are two magic eyes? Seems a little pointelss to waste EFM11 only as low frequency amplifier if usually it functions both as amplifier and magic eye.

Regards

Piotr

Tomasz Szczesniak
05.Jun.16
  2

Probably to use tubes with not working display function, but with good driving built-in pentode. Such eyes could be cheper than EF11 tube

Michael Watterson
06.Jun.16
  3

Perhaps the pentode section controls the gain of the triode section (via the deflector), so it's a little like a 7660 tube. Maybe part of AGC / AVC system. I'd have to look at schematic/circuit.

So a separate pentode and triode would not have same function, though using a pentode on detector to drive IF amp screen grids to control gain has been done.

Tomasz Szczesniak
07.Jun.16
  4

EFM11 has no triode and pentode section. It has pentode and display section, display driving electrode is internally connected to pentode's screen grid. EFM11 is combined tube to work in dual function - AF amplifying and eye driving. (like older AM2). In this radio display screen is not used (display electrode is connected to ground), and only pentode section is used, to work as normal pentode. This is method to use partially working tubes (with defunct display screen). Similar situaction was with ZX Spectrum memory chips. There was used 32Kb chibs, they was in fact 64Kb chips with upper half-array non-working.

Piotr Jachymczyk
08.Jun.16
  5

Still I can't find any rational reason to put two tubes instead of one. Was there really so much defunct EFM11 that they decided to use them instead of simple EF11? As I look at the prices of tubes in old magazine, EF11 were slightly cheaper than magic eyes which in turn were cheaper than end pentodes. 

I can't check right now in what condition that EFM11 is, but screen looks like new. 

Michael Watterson
08.Jun.16
  6

The EFM11 is being used as a pentode. The only reason I can think of is that the tubes were purchased for production of a "short superhet" with EFM11 as magic eye, then they decided they wanted more gain, so bought EM1 as magic eye? It doesn't seem to make sense.

The Philips Colette is later set using a magic eye as power indicator and gain -1 audio amp to drive push pull, even though the tone contol amp colud have been used if a passive tone control had been used.  This seems even stranger.

I downloaded and printed the schematic to see for myself!

 

 
Minerva-Radio: 396-W
End of forum contributions about this model

  
rmXorg