The AKAI 1720 model reel to reel tape recorder described in this Manual is quite an old unit - circa late 1960's. As a consequence, the description of the mechanical details - and adjustments thereof - is quite critical. The manual does this quite well. The schematics are also well presented and have detailed PCB overlays. Probably the only negative is that some half-tone detail has been lost from the original manual as it has been scanned in simple B&W.
Text excerpt from page 1 (click to view)
ANT
RECEIVING FREQUENCY 39.925~40.225MHz 1st IF Filter
2nd IF Filter
DATA Filter
IC801 PREAMP EXPANDER LINE AMP Q102 TR RLY Q105 SIDE TONE CIRCUIT POWER DOWN /RESET 5.5V REGULATOR ALC Q101 BELLDETECT D101
1 2
RX Filter
1st Mixer
2nd Mixer
TX Signal TEL JACK
3 4
IF AMP
DET
29.225 ~29.525MHz 1st Local X201 11.15MHz PLL 2nd Local 11.150MHz DATA AMP
+~ ~
1 2
TIP RING
RX Signal
COMPRESSOR
LIMITTER
MIC AMP
IC351 RX DATA TX Filter TX AMP TX VCO X202 Q351 TX DATA Q353 CHARGE DETECT IC201 8V REGULATOR
