GD-1B Grid Dip Meter
Radio amateurs and servicemen have proven the value of this grid dip meter many times over, indispensable in the service shop, the laboratory, or the ham shack, for locating parasitics, spurious oscillations, neutralizing, determining RF circuit resonant frequencies, aligning IF stages, traps and filters, and correcting TVI. Can also be used to roughly determine capacitor and inductance values, and to provide a relative indication of power in transmitter stages. Originally the grid dip meter found its greatest application in the amateur radio field, but now it is used extensively in radio and TV servicing and in experimental laboratories.
With the oscillator not energized, the instrument acts as a absorption wave meter on high signal level circuits. Plugging headphones into the phonejack further extends the instrument's usefulness through operation as an oscillator-detector for determining the frequency of other oscillator circuits through zero beating.
Many factors were considered in the design of this outstanding instrument, resulting in a grid dip meter that is packaged with desirable features. Notice that one hand operation is possible. The grid dipper may be held in one hand and tuned, leaving the other hand entirely free for making circuit adjustments. A variable sensitivity control assures adequate range of sensitivity throughout the entire frequency range. Plug-in coils can be quickly changed, and cover the frequency range from 2 mc to 250 mc continuously. Spare, blank dial scales are supplied for the builder who wishes to hand-calibrate this particular instrument, or desires maximum accuracy at specific frequencies.
The GD-1B incorporates its own power supply and is transformer operated from the power line.
Additional Plug-in Coils
A set of two additional plug-in coils is available for the GD-1B. This set is the 3-prong mounting type and provides continuous extension of low-frequency coverage down to 350 kc. Dial correlation curves are included.
Specifications: Frequency Range... .2-250mc using 5 plug-in coils supplied with kit (350 kc-2000 kc with additional coil set). Meter Movement... 500 microamperes. Circuit... 6AF4 or 6T4 high frequency triode in a Colpitts oscillator circuit. Power Supply... Transformer operated with selenium rectifier. Physical Specifications... Length 7", Width 2½", Depth 3¼". Power Requirements... 117 volts, 50/60 cycles at 5 watts.