Dorchester 16 stereo decoder options

      Dorchester 16 stereo decoder options

      Hello, and Guten Tag,

      I have a SABA Dorchester 16 radiogram (musiktruhe) which I have restored to working order. It has no stereo decoder and I am looking to find one.

      I wanted to ask which decoders will work with my radio chassis. There is an EI14 (14/I) decoder available and I have also looked at the EI 16 decoders on radiomuseum.orgThey seem similar although the signal levels in the schematics are different. Can I fit the EI14 to my dorchester or will the gain be wrong? The pinout and power supply look to be compatible.

      many thanks for any advice.

      Kevin.
      Hello Kevin.

      I think your Radio looks like this
      if yes, Decoder must bee E16 US with 75microsec. Deemphasis
      if not, show an picture near decodersocket
      maybe Type US12/16 is the right one.
      where is your locations? Country
      decoder
      Dateien

      Dieser Beitrag wurde bereits 3 mal editiert, zuletzt von „decoder“ ()

      Its a different chassis. Please find attached some photos.

      The schematic covers:
      Dorchester 16 (my model)
      Excelsior 16
      2560US (for US market)

      FM is setup for 50us de-emphasis, as you would expect as the unit lives in the UK. There is a 9pin socket for the decoder with the bypass plug installed and no decoder.

      many thanks,

      Kevin.

      PS we're still in the Eu, and if I had my way we would stay in..
      Bilder
      • IMG_20180904_182222.jpg

        317,4 kB, 1.024×768, 19 mal angesehen
      • IMG_20180904_182232.jpg

        276,15 kB, 1.024×768, 14 mal angesehen
      • IMG_20180904_182228.jpg

        264,05 kB, 1.024×768, 13 mal angesehen
      All right Kevin.
      Thanks for the pictures.
      the German Table-model ist Freudenstadt 15 STEREO

      radiomuseum.org/r/saba_freudenstadt_15_stereo.html

      you must have Socket Connection EI / 16 with R20 and R45

      If you want to sale an E16 orig. send me a Mail for price

      hans
      Dateien

      Dieser Beitrag wurde bereits 7 mal editiert, zuletzt von „decoder“ ()

      Hans,

      thanks for the clear response. So all I need to do now is wait for the correct decoder to show up. But this could take a long time?

      If I look at the schematics for E14 types and E16 types, they are very similar. The 38kHz doubler is different - on EI14 T2 is just a tuned amplifier with fixed biasing and the output rectifier is ground referenced. On EI 16 the rectifier is biased slightly positive through R13 and there is an overall level control from Gr11 to the base of T2 via R9.

      E16 also has provision for the mixer inputs to be balanced with P1, not in E14.

      So apart from some minor improvements to the 38kHz doubler, they are similar, and I'm not sure why the indicated levels on the schematics are so different. The AF gain is the same in each circuit.

      On the other hand, looking at your picture, Its possible the E14 would not fit mechanically, due to the long IF cans - E12/16 looks compact.

      Regards,

      Kevin.
      Kevin,

      the original decoder witch the noval tube-type plug is rather hard to find and expensive. Hence, I recommend to use an E 16, which can be found much easier. It has been used with many sets, for example in the Konstanz 16 and 18 and in Stereo I, sets which are easy to find on ebay etc.

      You will recognize this decoder has no noval tube type socket (instead, the pcb itself serves as plug, like today's computer boards), but this can easily be added - SABA did that themselves in some sets, as you will see in the schematics exerpt (click on the pic!):

      Regards, Stefan
      Bilder
      • Decoder 16.jpg

        60,25 kB, 1.041×307, 13 mal angesehen