Note
QST, Jul 1967, p. 129.
CQ, Dec 1967, p. 73.
Ham Radio, Jul 1968, p. 79.
The Comdel DW-1550 is a two-piece in-line directional wattmeter and VSWR bridge designed for HF and low-VHF RF power measurements, originally manufactured by Comdel Inc. of Beverly, Massachusetts.
Features
– Two-Piece Architecture: The system consists of a remote RF coupler inserted into the transmission line and a desktop display/control unit connected via a 3-conductor interconnect cable. The two units can also be bolted together to form a single combined unit if preferred.
– True Power Measurement: Measures forward and reflected power independently to determine absolute power output (forward minus reflected power).
– Built-in SWR Bridge: Eliminates the need for external lookup tables or charts by providing direct VSWR readings using dedicated `SET` and `READ` modes on the selector switch alongside a calibrated VSWR scale on the meter.
– Unique "ANT. TUNE" Mode: Features a specialized antenna tuning mode on the function switch that displays a combined forward and reflected power indication. This allows operators to tune antenna couplers for maximum meter deflection without accidentally creating a zero-reflection/zero-output fault state that could damage equipment.
Specifications
– Frequency Range: 1.5 to 60 MHz
– Power Measurement Range: 0.2 to 1500 Watts full-scale
– Power Ranges (Full Scale): 15 W, 150 W, and 1500 W
– Power Accuracy: ±1 dB
– Nominal Impedance: 51 ohms nominal
– VSWR Range: 1.0:1 to 4.0:1
– Residual VSWR Error 1.1:1 (1.5–60 MHz); 1.05:1 (2.5–30 MHz); negligible (3.5–25 MHz)
– Insertion Loss |Negligible
