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Reel to Reel Tape Machines / Re: Technics 1500 capstan motor speed problem UPDATE AND QUESTION
« on: November 15, 2011, 08:01:38 AM »
Hello all,
Finely got the speed problem resolved. The tape tension idlers needed cleaning/lube, pulled the capstan servo board, checked it for bad diodes, caps, resistors, put the board back in, reseated the connectors, including one the was loose on the reel control board and carefully went through the alignment procedures several times. The oscillator pot is near the end of its adjustment range but the speed issue is resolved for both fixed and variable speed. I was surprised that there was quite a bit of interaction between the fixed speed alignment and the variable speed alignment as I thought the circuits were pretty much independent of one another. Thanks to the forum for the advice.
QUESTION: I found a "replacement" board for the capstan servo control board but while about 3/4s of it matched, the connectors were different.
The one in my RS1500US is Technics part #: QJI0745RP
The replacement board (which I could not use) is Technics part #: QJI0745RP E The "E" seems to be a later revision or for use in one of the other RS15XX family.
Does anyone know which Technics model (maybe a 1506 or 1520?) this board is used in?
Thank you, Bob Edwards
Finely got the speed problem resolved. The tape tension idlers needed cleaning/lube, pulled the capstan servo board, checked it for bad diodes, caps, resistors, put the board back in, reseated the connectors, including one the was loose on the reel control board and carefully went through the alignment procedures several times. The oscillator pot is near the end of its adjustment range but the speed issue is resolved for both fixed and variable speed. I was surprised that there was quite a bit of interaction between the fixed speed alignment and the variable speed alignment as I thought the circuits were pretty much independent of one another. Thanks to the forum for the advice.
QUESTION: I found a "replacement" board for the capstan servo control board but while about 3/4s of it matched, the connectors were different.
The one in my RS1500US is Technics part #: QJI0745RP
The replacement board (which I could not use) is Technics part #: QJI0745RP E The "E" seems to be a later revision or for use in one of the other RS15XX family.
Does anyone know which Technics model (maybe a 1506 or 1520?) this board is used in?
Thank you, Bob Edwards