Note
The HM-2102 was released in time for Christmas in 1973. It was a big hit because low-cost VHF wattmeters were essentially unknown at the time. It was designed to match the popular HM-102 HF wattmeter and has a frequency range of 50 to 160 MHz, a maximum power rating of 250 watts, and a built-in SWR bridge. There are two switch-selectable ranges—1 to 25 watts and 10-250 watts. Accuracy is 10 percent of full scale. SWR sensitivity is less than 10 watts.
Other features include a removable sender unit that permits the meter to be placed up to six feet away. The 2102 may be placed in the line permanently with “little or no loss.” The unit is fitted with SO-239 connectors and has a light green cabinet with green wrinkle front panel. The HM-2102 is designed specifically for 50Ω systems, and will not function well with other impedances.
Calibration controls and a NORM/CAL jumper are located inside the sender unit.
At a distance the HM-2102 is indistinguishable from HM-102 making it easy to overlook.
References:
Brief description. Popular Electronics, Oct 1973, p. 117.
Better balancing. Ham Radio. Jan 1975, p. 56.
Modifications. Ham Radio. Sep 1975, p. 64
High power calibration. Ham Radio. Feb 1976, p. 70.
Frequency range: 50 to 160 MHz
Wattmeter accuracy: ±10% of full-scale reading (with 50Ω resistive load)
Power handling capability: 250 watts
SWR sensitivity: less than 10 watts
Impedance: 50Ω nominal
SWR bridge: continuous to 250 watts
Photos, general information and specifications from "Heathkit: A Guide to the Amateur Radio Products," by Chuck Penson, WA7ZZE. Used with permission.