Electrical Research Lab 5721 Schematic

Get a print!
Price: $8.00
In stock
Product Information:
Manufacturer:Electrical Research Lab (Sentinal)(ERLA)

Schematics Content:

Please note: this content is a computer-generated interpretation of the above schematic and is provided only to help assist you in locating this schematic. For the actual text, please consult the schematic above. Thank you.

Page 1:

MODEL 5700,5721

Schematic ,Voltage
Parts List


.udmudno 3 gum Baku #som i

nd." u and


.Emacs-.So omgnnuuooau huh .an N

.SuSE-ov Z; aou .au Him
ucunuuaeo :ob com .FHS ._..

unmnscou museum

. >> Bi( '3 iii 1 i255

"023:00 mama

own m

roar V


? Him

Page 2:


MODEL 5700.5721

m7172-l It may be found that stations on the short wave band are received at a slightly different dial setting

' than formerly received after changing the aerial dimensions. Using one of the antenna transmission systems

designed for man-made static elimination may prove beneficial for very difficult locations. Gare must be

taken in usixg this type aerial system as an improperly designed transmission system will decrease the range

of the receiver, particularly on short wave reception. Simply using a transmission system will not eliminate

the noise unless the flat top of the aerial can be erected outside of the field of disturbance. A shielded

lead-in is not recommended as the signal loss on short waves will be excessive. The antenna should be con-

nected to the red lead coming out at the rear of the chassis and for best results it is recomended that a
good ground be connected to the `block lead coming out at the rear of the chassis.

BAND SELECTOR SWITCH: Two different frequency bands are available, the frequency range being;

Selection of the desired frequency bend is made with the band selector switch blob, which is located on the 'y
lower right front of the cabinet. 'hen the bam selector switch is placed in the maximum left hand position

the receiver is operating on the 5.2 to 16 mepcycle land. For operation on the 17l5 to 535 kilocycle band V
place the bond selector switch lmob in the mazdmum right hand position. Both, bends are calibrated on a single

dial, one section of which is calibrated in kilocycles, 1715 to 535 kilocyclcs, and the other section ie cal-

.ALIGHIIEHT PROCEIIIRE: Only when an IF transformer, antenna or oscillator coil is' replaced should it ever be
necessary to realign the receiver. For`a1igning either the intermediate transformer or the variable conden-
ser it is absolutely necessary that a good accurate calibrated oscillator be used with some type of output

measuring device.

l. connect the hide side of the oscillator output to the control grid of the 2A? tube leaving the grid cap
disconnected. 'l'he ground side of the oscillator should be connected to the receiver chassis.

2. Set the oscillator at 465 kilocycles (this must be accurate) and udJust the output of the oscillator so
that a convenient reading is obtained on the output meter.

5. Align the first intermediate transformer by turning the intermediate transformer brass hext adjusting
nut located on top of the intermediate transformer can up 'and down until maximum reading is obtained on the
output meter. Then adJust the trimmer screw located inside the brass hex nut for maximum output.

4. Adjust the second I. F. transformer in the same manner as the first Il. F. transformer.

VARIABLE CONDENSEB ALIGKIIENT; It is essential that the -folloving instructions be carefully adhered to in
the order given otherwise the receiver will be insensitive ond the dial calibration will be inaccurate.

1. Connect the high side of the oscillator output to the set antenna lead and the oscillator ground to
the receiver chassis.

2. Place the band selector switch for operation on the 16 to 5.2 mcgacycle band.

5. Set the oscillator frequency to exactly 15 megacycles and adJust the receiver dial to exactly 15 mega-
oscillator gang condenser section. 'me oscillator trimmer condenser is mounted on top of the rear section of A4(
the variable condenser. The front section of the variable condenser tunes the antenna stage. `

4. Place the band selector switch for operation on the 1715 to 535 kilocycle band, set the oscillator s

exactly 1400 kilocycles and tune the receiver dial to 1400 kilocyeles. mm Il 'mls 1400 nwcycm slsmu,
B! ADJUSan TEE SHALL IRIIIER COSER which is located underneath near the center and towards the front
of the chassis.

5. laxt udJust the antenna variable @ng condenser section trimmer condenser for mximum output (front
section .

6. Leave the receiver operating on the same band and set the oscillator frequency to approximately 600
kilocycles and adJuot the dial to approximately 600 kilocycles. Then while rocking the variable condenser
sligitly to the right and left, adJust the 600 kilocycle padding condenser which is located below the speaker
and accessible through the front cf the chassis for maximum output.

7. Recheck the 1400 kilocycle adjustment.

8. Place the band selector switch for operation on the 16 to 5.2 megacycle band and tune the dial to ex- Q
actiy 15 megacyoles and set the oscillator frequency to 15 megacycles. Then adjust the trinuuer condenser
which is located underneath and toward the center of the right hand side of the chassis for maximum output.

me completes the alignment procedure and it is suggested that all the adjustments be rechecked. *I

Please note: we carry a wide range of products which will fulfill the specifications above. Please use our search function or browse our products to find what you need!