• This topic has 6 replies, 2 voices, and was last updated 7 months ago by Guenni75.
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    • #7908
      Guenni75
      Moderator

      What was before the transistor? Yes – electronic tubes (valves) to drive a radio (1920…1970), guitar amplifiers (remember Jimi Hendrix etc.), computers (ENIAC, IBM etc., 1942…1962) and so on…

      Why not use tubes with Lectron? There are a lot of offers of Lectron blocks with 6.3V AC filament tubes from Lectron, GmbH – for example the model 1120 (ECC8x … EL95, using a special power supply), but I like to use battery driven tubes with lower current.

      But one thing is different to transistors / ICs: the high impedance of input (grid[s]) and output (anode/plate), so these blocks have to be changed or new built – and the two batteries!

      The simplest way is to use the circuit of the famous Emerson 747 pocket radio:

      The Lectron circuit looks like this (several new built blocks to solve the problem 😉

      The 27x54mm blocks with the tubes have clear covers (from NOS), for the photo I placed the printed paper covers on the blocks for better understanding / reading. Not many special parts, most of them from a transistor pocket radio.

      With a special block containing a 7 pole pencil tube socket I may test the tube before using – that’s my first intention – better than a tube tester!

      Knowing me everybody will think: that’s not all…yes, here we have the version with German steel tubes (no glass inside!) from 1939 – same circuit, new blocks for the larger tubes. Below the pencil tubes with clear cover, and: a “magic eye” (DM70 = exclamation mark symbol) for the signal strength!

      I had the opportunity to purchase a set of pre-series (sample set for developers) manufactured in June 1939:

      With these tube sets BRAUN first produced this nice portable radio (“the PICCOLO for the housewife”, 1940):

      So this “circle” is closed – but only with the AM Broadcast band, LW and SW are possible, too, by changing some blocks.

      Years before lots of 2G21 pencil tube were offered. They had been used in early Walky-Talky units (so-called “bananas”) and could be purchased for less than a half US dollar per piece. So I decided to use this converter tubes for universal purpose. I was called an idiot (by tube collectors) but I found a way for a future use, here it is:

      With this circuit I am able to test also system-renewed versions, so it’s very worthy for me.

      The anode/plate battery could be 5 or 6 x 9V in serial connection, with a 1.22V NiCd accu for the filament – or a suitable power supply with stabilized voltage(s).

      That’s not the last circuit with tubes – enjoy!

      Best,

      Günther

      • This topic was modified 7 months, 1 week ago by mwpeters75. Reason: Changed font and size styling for easier reading
    • #7910
      mwpeters75
      Keymaster

      Wow, this is amazing Günther!  I love the history that you have provided and the way that you have incorporated the Lectron System.  Truly innovative and very engaging!  Thank you so much. 

      What a rarity to have the 1939 prototype-early issue of the steel tubes.  This is the first time that I have seen such things.  You are a treasure trove of history and electronics inventions!

      I have to say that I would love to see a video demonstration of your tube based Lectron System shown in the above photos!

      Thanks so much,
      Michael

      • This reply was modified 7 months, 1 week ago by mwpeters75.
    • #7937
      Guenni75
      Moderator

      To show more details here is at first the open 54x54mm block with two pencil tubes 2G21 as 2-stage-AF-amplifier (incl. a germanium diode as demodulator) as a replacement for the DAF11 – same size as the legacy system #8054 (2-stage-transistor amplifier 😉

      the next one shows the DM70 in turquoise with the question mark symbol. full colored symbol = no / bad signal, the less color the better the radio station signal. On the right the mentioned block with a pencil tube socket for testing reasons.

      Last but not least the different two main outlines of the steel tubes, left old version until 1942/43 (with the special socket) and to the right the lower ones as follow-on to save material (steel, nickel, brass, bakelite). These tubes were used until 1951 for portable radios (no new production, only using up NOS inventories) until the subminiature 7-pole glass tubes were available (DK91, DF91, DAF91, DL92 etc.). Please note the right tube with proof date 10/[19]44 = it’s my year of birth…

      If anybody has interest to build this receiver with the tube lineup DCH11-DF11-DAF11-DL11, I still have several pieces for sale…

      Best,

      Günther

      • This reply was modified 7 months, 1 week ago by mwpeters75. Reason: Changed font and size styling for easier reading
      • #7960
        mwpeters75
        Keymaster

        I notice the word ‘wehrmacht’, a word denoting the collective armed forces of the German military during WWII.  Were these metal tubes developed to be more durable in military applications?  Given the 1943 and 1944 dates, were these part of Albert Speer’s initiatives to improve German technology as armaments minister?

        Thank you,
        Michael  

    • #7961
      Guenni75
      Moderator

      The development of these tubes (first letter: D= battery 1.2V, E= 6.3V, U= 100mA AC/DC, V= 50mA AC/DC) has NOTHING to do with any NAZI activities/plans.

      Please read also https://de.wikipedia.org/wiki/Stahlr%C3%B6hre – with help from Google translate.

      G.

      • This reply was modified 7 months, 1 week ago by mwpeters75. Reason: Changed font and size styling for easier reading
      • This reply was modified 7 months, 1 week ago by mwpeters75.
      • #7963
        mwpeters75
        Keymaster

        Hi Günther,

        Thank you for the link with the additional information.

        Since the article says that development of these tubes was circa 1937, then development was during the Nazi regime (1933 – 1945) and funded and driven by them.  That is an historical fact.   So was the development of the V2 rocket and jet engine/aircraft (Messerschmitt Me 262). Hans Joachim Pabst von Ohain developed the first practical and functioning jet engine in 1936.  Technology evolved as it often does during wartime. Germany was the world leader in developing numerous technologies during WWII as evidenced by by the US Operation Paperclip program which brought (forcibly in some cases) the cream of Germany’s technology talent (some 1800 scientists plus 3200 family members) to the US in 1946-47. Wernher von Braun and his team are just one example.  The US space program and NASA greatly benefited from the knowledge of these men.  Many of these scientists had been Nazi party members and some had been Nazi party leaders. Those were the times. 

        Better the Allies had their services in the post WWII world than the USSR.

        Thanks again for all your recent contributions.  Very interesting!

        • This reply was modified 7 months, 1 week ago by mwpeters75.
    • #8035
      Guenni75
      Moderator

      The last post is off-topic because – as mentioned in my reply – the development of this tubes started in 1917 and took much time to develop the required process for best results. The advantage was the short connections, low height (!) and the electric shielding (net hum etc.). As a member of Radiomuseum.Org it’s quite easy to analyse the usage of this kind of tubes:

      The first available types were the E (6.3V filament serial/parallel: ECH11, …) since 1937/38, followed by D (batterie 1.2V filament serial/parallel: DCH11, …), V (50mA filament serial: VCH11, VCL11, …) and U (100mA filament serial: UCH11, …), used in car radios, portables and table radios. Not all tubes were made of steel; the power tubes (output stages, rectifiers) were made of glass in dome shape. The common sockets were equal.

      E-series:  >1000 radio models 1937/38…195x

      D-series:    88 radio models  1939/40…1952

      U-series:   679 radio models  1939 … 1952

      V-series:  143 radio models  1938 … 1951  (VF14 … 1959)

      Only ONE model (with a DDD11 tube) was no radio: a weather probe…

      All these tubes were used in radio models in following countries: Norway, Sweden, Finland, France, Austria, Switzerland, Czechoslovakia and Germany (!).

      There was NO MILITARY USE and no support/demand/whatever of any regime!

      In the USA also steel tubes were developed and used in radio models, amplifiers etc., like e.g. the 6L6 (RCA) since 1936, 6AG7 since 1939 and the Russian tubes like the 6П9 since 1946. These are only samples for hundreds ore mode other (similar) types.

      In USA proofed tubes with certain characteristics were certified with “JAN” (Jointed Army / Navy).

      In Great Britain quite similar (tubes and semiconductors). stamped as “CV…” types.

      In Germany until 1945 the military tubes/valves started with: LB /LD /LG /LK /LS /LV (L=Airforce), and RD /RG /RK /RL / RV (R=Army).

      G.

      • This reply was modified 6 months, 3 weeks ago by Guenni75.
      • This reply was modified 6 months, 3 weeks ago by Guenni75.
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