HF Impedance Transformer Kits

Magnetic Long Wire Antenna Matcher (9:1) for SWL, 100 KHz-30 MHz

MLB-2
$79.95
In stock
1
Product Details
MPN: MLB-2

Palomar Engineers Magnetic long wire antenna matche has been redesigned for shortwave listeners who listen to a broad frequency range from VLF to HF and others needing to match a long wire antenna to 50/75 ohm coax feed line cable.

Specifications: Frequency: 100 KHz – 30 MHz. Input: 50/75 ohms for coaxial cable. Output: High impedance. Connector: SO-239 (for cable), wingnut/solder lug wire lead (for antenna). Mounting: Stainless steel eyebolt. Size: 2.5” diameter. Case: White PVC sealed weatherproof. External ground bolt with wing nut for external counterpoise or separate ground.

The long wire antenna often has a high impedance in the 500-1000 ohm range and the MLB-2 transforms this high impedance close to efficiently couple the received signal to the receiver. A long wire antenna with a matching balun such as the MLB-2 often has a 12 db (2 “S” units) better signal than a long wire without a matching balun.

Typical Installation Diagram

MLB 2 Installation Diagram - HF Impedance Transformer Kits

MLB-1/MLB-2 Typical installation diagram

For best results we recommend that the coax feed line be at least 1/4 wavelength on the lowest operating frequency since the coax braid is used as a counterpoise if you don’t use the external counterpoise terminal on the matching unit. We also recommend a feed line choke at the end of the coax feed line near the radio to prevent RFI common mode current (from neighbor noise sources) from interfering with the radio – check out the info below on feed line chokes.

Also available as a complete ready to hang SWL antenna. (see related products).

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These impedance transformer kits have been designed for the Do-It-Yourself (DIY) enthusiast and Instructor workshops on baluns and ununs for antenna matching and RFI use.

The impedance transformers are classified in ratios of 2:1 (100:50 ohm) to 16:1 (800:50 ohm).  The outputs can be configured as balanced (Balun) or as unbalanced (unun) with respect to the inputs which are considered all unbalanced coax at 50 ohms.  All impedance transformers are designed for 1.8-31 MHz unless otherwise specified.