The SP/TF is one of the four older style Golmar speech amplifiers still available.
Golmar speech unit SP-TF
The Golmar speech unit SP-TF is one of the four older style Golmar speech amplifiers still available.
The connections on the unit are as shown in the close up image.
note: the SP speech amplifier looks very similar but they have different terminal connections. Check closely your existing unit.
This unit is fed by 12v AC only and then rectifies to 8v dc internally for the speech.
It has two pots. for adjusting the speech volume at both the panel and handset.
70mm x 80mmx 25mm