Previous Index Next
Page 274
(previous) (Page 000274) (next)
 
 

 

   
 
     
 

 

WIRELESS TELEGRAPHY 249

seven-eighths inches in diameter outside. It should be

' given two or three coats of shellac both inside and out so

that it is thoroughly impregnated, and then laid away
until dry. This treatment will prevent the wire from be-
coming loose after the tube is wound, due to shrinkage of
the cardboard.

After having become dry, the tube is wound with a single
layer of No. 2 5 B. & S. gauge green silk-covered wire. The

 

 

r 71‘

u

 

Slider Rod.
3/u'sauaat

5hr cuf in Tuner
Head to receive

evacuean a '

ron run’uszc-r sh“, Rod’

‘0 70 c0
ucao

SQUARE Tue: \—
10 hr noo s \-
onto

 

 

 

ISCR‘W 3°!-
70 runs
4£L£CTR38£
5" no cont. RN 0
"’;7an; oococaeo
7° 70.:

Coil #Hoad. and“
FIG. 20L — Details of the Tuning Coil.

wire must be wound on very smoothly and tightly, stop-
ping and starting one-quarter of an inch back from each
end. The ends of the wire are fastened by weaving back
and forth through two small holes punched in the card-
board tube with a pin. '

The Winding should be given a single coat of clear var-
nish or white shellac and allowed to dry.

The coil heads or end pieces are cut from one-half-inch
wood according to the plan and dimensions shown in the
accompanying illustration.

Previous Index Next