Heathkit AM-1 Antena Impedance Meter

The AM-1 Antena Impedance Meter is basically a resistance type SWR bridge.
However, one arm of the bridge has been made variable, thus greatly increasing
the versatility of the original bridge circuit. By means of this modification,
it is possible to measure radiation resistance and resonant frequency of an antenna,
transmission line impedance, approximate standing wave ratio and optimum receiver input.
It also can be used as a phone monitor and by connecting a tuned circuit and small
antenna to the output terminals, it may be used as a field strength meter where high
sensitivity is not required. The AM-1 may be operated from any low power RF source
not exceeding 1/2 watt. The wide frequency range and portability of a grid dip meter
such as the Heathkit GD-1B, make it ideal for use with the Antena Impedance Meter.
The AM-1 uses a specially tested potentiometer in the variable bridge arm to maintain
calibration accuracy and to cover a range which will include the popular 600 ohm
transmission feed lines.

Frequency range: 0 - 150 mc

Impedance range: 0 - 600 ohms

Null indicator: 100 ua meter

Dimensions: 2 1/2" x 3" x 7"

Weight: 1 lb