front  panel  starting  at  the  left  edge  and ex-
tending from top to bottom. The dial has five 
frequency  bands,  A  through  D and a LOG 
scale marked 0 to 100. Band A goes from 550 
to  1500  KHz,  Band  B  from  1.5  to  4.0  MHz, 
Band C from 4.0 to 10 MHz and Band D from 
10 to 30 MHz. Below the actual dial marking 
area four  of the  controls  and  the  phone jack 
pass  through  holes  in  the  plate.  They  are 
(left-to-right)  BFO,  VOLUME,  BAND,  MODE 
and  PHONES.  To  the  right  of  the  dial  plate 
and  vertically  spaced  are  the  larger  MAIN 
TUNING (top) and BANDSPREAD  knobs.  To 
the right and slightly above the MAIN TUNING 
knob  is  the  small  SIGNAL meter. and to the 
right  and  slightly  above  the  BANDSPREAD 
knob is the small band spread slide rule dial. 
marked 5–0–5. The BFO is turned off by turn-
ing its control fully counterclockwise. 
The  rear  panel  (Figure  2)  is  rather  barren. 
Everything is located along the bottom edge. 
From left to right (as viewed from behind) is 
the  ferrite  rod  antenna  for  the  broadcast 
band, the 3-wire AC power cord, a two screw-
type  terminal  strip  marked  ANT and GND 
and a two-position slide switch  marked OFF 
ANL ON (automatic noise limiter). 
The SW-717 has a built-in speaker located on 
its right side-panel;  an external  speaker  may 
be plugged into the PHONES jack since it is 
low  impedance,  taken  directly  off  the  inter-
nal speaker. 
The SW-717 operates on 120/240 VAC 60/50 
Hz.  depending  on  how  the  transformer  pri-
mary  is  wired.  The  instruction  manual  in-
cludes  the  necessary  information  should  it 
need  to  be  changed.  The  receiver  draws  8-
watts. 
The SW-717 Circuit: 
Superheterodyne  receivers  have  been  dis-
cussed in prior reviews so only the highlights 
will be covered. Figure 3 is a simple block di-
agram of the SW-717, showing its simplicity. 
Only the more unusual aspects of the circuits 
will be covered in some detail. A schematic of 
the SW-717 is available online
4
 and a small-
er copy (Figure 9) is reproduced at the end of 
this article.