Heathkit SG-6 User Manual

24. Observe . that the phone plug (V41) cap unscrews from the plug tip assembly. Assemble the
test lead as shown in Fig. 13 checking closely to see that the connection of the inner conductor
goes to the proper solder lug of the phone plug. Screw the cap over the plug before attaching
the alligator clips (V44).
Plug the 6C4 tubes into their sockets and the generator is ready for test.
Fig. 13
CALIBRATION
DROP OF SOLDER
METALLIC
COATING
MAY.IM UM MIN IM UM
CAPACITANCE CAPA C ITANCE
!D£NT/t=Y/N6 TRIMMER FOR MAX/MUNI
AND MINIMUM CAPACITANCE 5ETTIN65
Fig . 14
On a receiver, tune in a strong station of known frequency between 1,200 and 1,600 Kc.
Place the test lead from the generator close to the antenna of the receiver and tune the generator
to approximately the same frequency. This will cause a whistle in th~ 1 receiver. The lowest
pitch whistle (zero beat) indicates that the signal generator and station are on the same fre-
quency. Now set the generator's plastic indicator to read the same frequency as the station, and
adjust the trimmer to again give zero beat. The trimmer should be nearly in the minimum ca-
pacity position. (Fig. 14). The calibration will now hold quite accurately on all bands.
The calibration on the higher frequency bands may be upset by excessively long leads on . the
tuning assembly. Such variations in inductance cannot be compensated for by trimmer adjust-
ment.
If the trimmer is in the minimum capacity position before zero beat can be obtained, there is an
excessive amount of distributed capacity due to wiring in the tuning circuits. Make sure all the
"hot" leads (from the top lug on the coils to the switch, and from the switch to the tuning conden-
ser and trimmer) are at least a quarter inch away from the metal chassis and all other wiring.
After calibration is completed, place the rubber feet on the
cabinet ( T32 ) (Fig. 15) and fasten on the carrying handle
(079) using two 10-24 x t handle screws (030). Slio the chas-
sis into the cabinet and using #6 xt sheet metal screws {0102)
fasten the panel to the cabinet. In the back of the cabinet,
fasten the chassis to the cabinet using sheet metal screws.
ACCURACY
Fig. 15
Any signal generator is designed as a convenient and controllable source of modulated or un-
modulated signals. No signal generator is designed as a frequency standard ·. Expensive stand-
ard signal generators have fairly accurate (3-20%) attenuators which control the output voltage,
and the calibration accuracy is rarely closer than 1%. The Heathkit generator may be expected
to fall within 2-3% of the frequency calibration, which is quite satisfactory for service work and
alignment. In receiver alignment, the frequency at which the particular adjustment is made is
rarely critical, but the adjustment itself for maximum signal output from the receiver is . fre -
quently
quite critical.
Page 8

Heathkit SG-6 Specifications

General

Brand	Heathkit
Model	SG-6
Category	Measuring Instruments
Language	English