Description
While primarily designed for use with a "Loop on Ground" antenna, this is an excellent 9:1 isolation balun for any receive application. Separate input and output windings provide a high level of isolation and noise reduction plus, to maximize performance, two mix 77 ferrite beads are permanently joined together to form a binocular ferrite to better accommodate the windings for the unit.
We use 77 material because it's the optimum material for the build. This ferrite material is lower loss than the more common 73 mix, has a permeability that places the "sweet spot" of performance in the low bands and is perfect for use with a LoG for receive on 160 & 80m. The number of turns results in lowest loss in the frequency range of the 160M and 80M bands.
Loss is 0.2 to 0.3 dB from the AM Broadcast band through the 20M ham band. With a 450 ohm resistor across the secondary, the primary will have a VSWR of 1.2 maximum from below the AM Broadcast band to 30 MHz. This transformer can also be used as-is with 75-ohm line, the extra loss due to mismatch is so low that you will never measure the difference except on the test bench. Note that this type of antenna typically requires a transceiver with a separate receive preamp or an external receive amp to bring signal strength up to typical levels.
**CAUTION**
The enclosure for our low power units is small, lightweight and portable but is not weatherproof and not intended for long term or permanent outdoor use. If used in a permanent outdoor installation, additional attention must be given to weatherproofing and strain relief. Damage caused by such use is not covered under our warranty.
Dipole mount and alternate RF connectors are available in "Accessories & Connectors" section of our website
Specifications
Core Material | Special mix 77 sleeves custom configured as a single binocular ferrite. |
Winding Type | Separate windings for input and output, 3:1 ratio |
Winding Material | Enameled magnet wire |
Power Rating | This is a receive only unit |
Useable Frequency | 1-31 MHz |
Insertion Loss | Less than 0.2 - 0.3 db frequency dependent |
Connectors | SO-239 connector is nickel plated with Teflon insulation. Alternate connectors and Mounting Options are available in the Accessories section. |
Hardware | All Stainless Steel |
Enclosure Type | Polycarbonate (ABS) box with bottom plate that fits flush with the case Plate is an exceptional fit that can be easily weatherproofed if desired. |
Dimensions | Very compact and lightweight 3x2x1.5 inch - Link to dimensional drawing |
Additional Info | Excellent and efficient low band operation |