Fisher AMBASSADOR 4 A 60 X Service Manual

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THE FISHER

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MODEL A-6ox

PRICE: $1.00

FISHER RADIO CORPORATION ' NEW YORK

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ALIGNMENT INSTRUCTIONS

Read These Instructions Witll Extreme Cue Before Attempting Alignment.

CHASSIS: Turn the station selectors completely counterclockwise, without forcing. Dial pointers FM RF modulated 30% (i 225 KC deviation] at 400 cps; AM RF modulated 30% at 400 cps;
should be at zero index mark on logging scale. It not, reset the dial pointers Disconnect the

external antennas and the antenna link. Set Volume Control to minimum lccw.) INDICATOR: DC VTVM, AC VTVM, and scope for olignment filteradjustmentl

When using an oscilloscope for alignment, set the output level controls for no overload, as shown ALIGNMENT: Allow the chassis and lest instruments to warm up for at least fifteen minutes.

by the proper waveform shape. Adiust the llne voltage for H7 volts AC, 50-60 cyclesl Use fully insulated tools: a small screw-

driver lor all trimming capacitors; a K-lran tool for ll, 22, ZS, 26 and Z7,- a hex tool for 23,

SIGNAL GENERATORS: The signal generator equipment must be able to supply the following: 24, L2, L5, L6 and L R For AM alignment, short iunction of C55 and N24 to ground.
cuAssts SIGNAl GENERATOR INDICATOR AlloNMmt
steps - -- , _,_.,, - , » e .-
SELEClOIt 555%?ng COUPLING FREQ. MOD, TYPE CONNECTION ADJUST INDICATION
zo 27
AM ALIG N M E N T Point oi no signal AM Gen. connected lhrv A 307. AM at AC VTVM to Ch. I: ' ,
' AM and no inteiteience tOIruI cop. to VA, Pin 7 55 KC 400 cps RCRDR Output $5,112? M°x""" W?!
AM Gent connected thru 0 T h 25
220.qu cap. a 7. AM at AC v VM to c t 3 L9, .
2 AM 600 K to antenna terminal 4 60° KC 400 cps RCRDR Output LI M°""'" ha

Disconned link between 4 8t 5

AM Gen. connected Ihru

220suuf cap. 30% AM at AC vrvm to Cit. a :53, Ge r
3 AM 1400 KC to antenna terminal 4 "m KC 400 cps RCRDR Output CSA M"" '°"9°
Disconnect link between 4 t. 5
4 Repeat steps 2 and 3 tar proper drol calibration and maximum output.
Polnt at no signal FM Gen. :onnected thru DC VTVM to 1'. 12. 13 Maximum possum
5 FM and no interictence 2.2.uut cop. to test point I '07 MC N°" test point 2 and 24, low who,

a bottom

Connect two 47K ohm
tcsistats in scncs
Point at no signal FM Gen. connected linu um C Conn! Zero reodtn on zero
6 FM and no interferanze 2.2»uul cop. to test point t '7 MC N°"" .V'VM WW!" the 2 '° center fcole
lunctton ol the two
47K ohm tesistols
and last point 3

FM Gen, connected lth 307. FM DC VTVM to test point 2 L6 L5 cncck tor sins wavelorm
7 FM 90 MC two IZO-ohm carbon resistors 90 MC |?7.5 KC Dev.) and scope to Ch, A i2 ' and adiust for maximum
to antenna terminals 2 and 3 at 400 cps RCRDR Output positive voltage
FM Gen. connected thru 30% FM Dc VTVM to test point 2 C96 and Check lot sine waveform
3 FM I06 MC two l20~ohm carbon resislors 106 MC [22.5 KC DevJ and scope to Ch. A cn and adiusl for maximum
to antenna terminals 2 and :l at 400 cps RCRDR Output politiva voltage
9 chcaI steps 7 and B at least once for proper dial calibration and maximum output.

NOTE: For collbroting both the AM and FM, use as low on output voltage as potsilslc tram you! signol generatol.