I have reverse engineered and drawn a schematic diagram of the circuitry in my Heath IT-3121.
I release this document into the public domain.for the use of anyone interested.
No guarantees of accuracy, fitness or safety are made relating to use of this document.
Caveat Emptor.
No fees may be charged for reproducing this document in any form beyond the cost thereof.
Have fun with it.
The IT-3121 has served me well, especially in the realm of restoration of high power amplifiers.
Not only has it been a good tool for matching parts but also for selecting new devices when originals are no longer available.
At some point in the future, I may release an updated schematic which would include alternative components for those NLA devices as well as improvements to the functionality of the instrument.
Tom Garson, Aural Technology, Ashland, Oregon
I release this document into the public domain.for the use of anyone interested.
No guarantees of accuracy, fitness or safety are made relating to use of this document.
Caveat Emptor.
No fees may be charged for reproducing this document in any form beyond the cost thereof.
Have fun with it.
The IT-3121 has served me well, especially in the realm of restoration of high power amplifiers.
Not only has it been a good tool for matching parts but also for selecting new devices when originals are no longer available.
At some point in the future, I may release an updated schematic which would include alternative components for those NLA devices as well as improvements to the functionality of the instrument.
Tom Garson, Aural Technology, Ashland, Oregon
Who wants to take on the daunting task to check if that copy is the same as the original ? ;-)
Jan
Jan
It's nice that there is a site that offers the original.
For the record, copyrights for virtually all original Heath manuals and schematics are owned by a fairly zealous oportunist who has, in the past, actively litigated against sites that made available copies of those documents for download. If that site is not located in the western world, it may be able to continue to list the schematic. Anyone who wants it should grab it while its available.
For me, I wanted to have a CAD based schematic that I can use to develop internal enhancements and for testing alternative replacement parts. My desire is to adapt it for identifying vacuum tubes and enhancement mode MOSFETS.
I'm fairly sure it's accurate, but have included disclaimers for obvious reasons.
For the record, copyrights for virtually all original Heath manuals and schematics are owned by a fairly zealous oportunist who has, in the past, actively litigated against sites that made available copies of those documents for download. If that site is not located in the western world, it may be able to continue to list the schematic. Anyone who wants it should grab it while its available.
For me, I wanted to have a CAD based schematic that I can use to develop internal enhancements and for testing alternative replacement parts. My desire is to adapt it for identifying vacuum tubes and enhancement mode MOSFETS.
I'm fairly sure it's accurate, but have included disclaimers for obvious reasons.