UTC CG-300 Pinouts??

Discussion in 'Tube Audio' started by zekk, May 29, 2011.

  1. zekk

    zekk Active Member

    Messages:
    195
    Hi Folks,

    Can anyone please help me to figure out the variable primary connections?

    Pri: 0v, 105v, 115v, 220v, & 230v.

    Sec: 625v - 515v - 0v -515v -625v.

    Data sheets does not show pin connection!

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  2. PakProtector

    PakProtector AK member

    Messages:
    3,377
    Location:
    Ann Arbor, MI
    hey-Hey!!!,
    I suspect the secondary is in two separate pieces, and likely the primary as well. One bit of primary will be 0-105-115 and the other 0-115 so the entire combination of input voltages can be configured( ex. the 220 is created with the 0-115 connected in series with 0-105 of the first bit I think ). Now the secondary is likely created by putting the two bits in series. Now if that is the case you can make a 615-110-0-110-615 secondary by reversing the polarity. Perhaps useful for creating a negative rail bor either bias or a cathode follower...:)

    See what is connected to what with an Ohm meter, the primaries will be low compared to the secondary and there *MAY* be a separate tap for grounding the core.
    cheers,
    Douglas
     
  3. zekk

    zekk Active Member

    Messages:
    195
    Thanks, Douglas!

    Using a variac to check out the pins, it's confirmed that the sec. taps are 7 to 11 at 625-515-0-515-625 respectively.

    Applying 105v to pin #1/#2, #4/#5, pins #7-9-11 reads 625-0-625v.
    The same 105v to pin #1/#3, #4/#6, pins #7-9-11 reads 515-0-515v.

    So, I've two pairs of primarys.

    If I series the primary for a 230v supply, will I be getting a doubled voltage across #7 and #11, eg: 1250-0-1250v? :eek:

    Regards, Zekk.
     
  4. zekk

    zekk Active Member

    Messages:
    195
    ... just answered my own question!

    By connecting pin#3 and #4 together and applying 230vac to pins #1 and #6, I got 625-515-0-515-625v on pin #7 to #11 respectively.

    Thanks all for watching.

    Zekk
     
  5. PakProtector

    PakProtector AK member

    Messages:
    3,377
    Location:
    Ann Arbor, MI
    But you can arrange a 220 connection and apply 120V to it and deliver a little more than half that voltage. It will cut the volts/turn and make it radiate less which may be useful in a lower voltage design a typical linestage would use.
    cheers,
    Douglas
     
  6. zekk

    zekk Active Member

    Messages:
    195
    Thanks again, Douglas!

    I'm building a SEUL TT22 with EL802 as driver.

    So, needs high voltage !

    Will post pics and schematic when ready.

    Regards, Zekk.
     

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