ELK Products ELK-SWR Surge Protector Module
Overview
The ELK-SWR is an RF directional coupler and power meter assembly designed to measure forward power, reverse power, and VSWR in RF transmission systems. The unit sits inline between a transmitter and antenna, using a true directional coupler architecture to deliver cross-needle analog readings at the same time—so you can see impedance mismatch and reflected power instantly without toggling between displays. Two models cover different frequency and power ranges: SWR-7 handles 26–30 MHz (CB), 140–160 MHz (2-meter VHF), and up to 2 kW forward; SWR-8 covers 420–460 MHz (70 cm UHF) and maxes out at 200 W. The insertion loss is less than 0.1 dB, so the meter does not attenuate your transmitted signal. Weight is 770–790 g depending on model.
Compatibility
The ELK-SWR works with any 50-ohm RF transmission chain: ham radio transceivers, amateur repeater systems, and commercial radio transmitters equipped with standard M-type (or optional N-type) RF connectors. Frequency and power selection determine which model fits your application—check your transmitter's center frequency and maximum RF output before selecting SWR-7 or SWR-8. The 50-ohm input/output impedance matches industry-standard coaxial cable and antenna systems.
Installation Notes
Install the meter in-line between the transmitter's RF output and the antenna system using coaxial jumpers rated for your power level. Set the RANGE switch to the correct multiplier (×1, ×10, ×100) before transmitting—this scales the meter face to your expected power level and prevents meter pegging. For SWR-7: ×1 reads 0–20 W forward (0–5 W reverse), ×10 reads 0–200 W forward (0–50 W reverse), ×100 reads 0–2 kW forward (0–500 W reverse). For SWR-8: ×1 reads 0–2 W forward (0–0.5 W reverse), ×10 reads 0–20 W forward (0–5 W reverse), ×100 reads 0–200 W forward (0–50 W reverse). Accuracy is ±10–15% on the ×1 range and ±5–10% on ×10/×100 ranges. The speckled black metal cabinet with grey molded front panel mounts on a bench or wall near your transceiver.
