The WiMo QRM Eliminator is a simple signal phasing device that can effectively reduce or remove noise interference for dramatically improved HF reception.

The QRM Eliminator is based on a totally innovative concept and cannot be compared to the performance of noise blanker or DSP circuits. Removing the noise before it gets to the receiver is the superior method of interference reduction. You may not believe the power of interference phase nulling until you have experienced it for yourself. Order the WiMo QRM Eliminator exclusively in North America from DX Engineering.

WiMo QRM Eliminator

Some fortunate radio enthusiasts live in rural areas where reception without any noise is possible. Even in those locations, where they know how clear and noise-free the MW and SW radio frequencies can be, sometimes a high-tension power line with bad connections or broken insulators will make noise that causes interference (QRM). Most Amateurs and SWLs (Shortwave Listeners) experience some receive interference that is caused by local electrical system hardware and by electronic sources. The list of offending devices seems to be endless, such as TV and monitor screens, computers, dimmers, low-voltage lighting and all types of electronics. Especially poorly made power modules and electronics can generate RFI. Most of us live in locations where local QRM causes problems for proper reception.

With the WiMo QRM Eliminator you can get rid of local interference almost entirely, up to an S9 level, with the likely result of completely clear reception! You don't have to understand the cause or type of interference nor do you need to know the location of its source. It doesn't matter if the interference originates from your own station or from a welding unit hundreds of feet away. The QRM Eliminator simply connects to the antenna port of transceiver and to the antenna (or amplifier input), without any radio modifications required. An additional user supplied auxiliary receiving antenna is required, such as a properly positioned 8 ft. outdoor dipole antenna or a simple 20 ft. wire in the shack, for example. This “noise sense” antenna receives mostly unwanted signal, while the transmitting antenna receives the same interference in a different phase along with the desired signal. The QRM Eliminator allows the adjustment of the amplification and phase to cancel out the unwanted signal before it reaches the receiver front end! Noise or interference nulling can provide over 45 dB of unwanted signal suppression, in many cases resulting in clear reception of the desired signal.

WiMo QRM Eliminator - Rear Panel

The QRM Eliminator is built into a shielded metal enclosure, functions over the frequency range of 3.5 through 60 MHz, and has a status LED to indicate when the unit is turned on for phasing. The unit has a built-in T/R relay with PTT control via a rear panel RCA phono connector for the transceiver amplifier keying line. The QRM Eliminator automatically switches the Main antenna connection to the transceiver during transmit. Also, simply turn the unit off to bypass the phasing unit for normal reception on the Main transmit antenna.

Additional data:Frequency Range: 3.5 to 60 MHzRF Power Handling: 125 watts CW or SSBRF Ports: Three (3) SO-239 (UHF female), 1 each for Radio, Main Antenna, Auxiliary AntennaPTT Keying: RCA phono femaleDC Power Input: 11-14 Vdc @ 150 mA via 2.1 mm DC connectorDimensions (WxHxD): 4.33 x 1.81 x 2.72 in. (110 x 46 x 69 mm)