* Help keep RF out of the shack. * Provides maximum transfer of RF to the antenna. * Suppress radiation from the feeder cable * Makes the antenna radiation pattern predictable. * Outperforms the competition by 24 dB common mode rejection! (see graphs) * Reduces QRN and TVI to the neighbors. The CB-1-1500 balun is useful as common mode feed line chokes or unbalanced coax to balanced antenna interface. SO-239 input to side terminal/eyebolt output. . Rated 1500 Watts PEP from 1-61 MHz. Common mode rejection up to -38dB over the frequency range. The CB-1-1500 is the balun version and the CU-1-1500 is the unun version (coax in and coax out). Use as line isolator, antenna interface, or as a common mode choke to keep RF on the antenna and off the outside of the coax braid. Much more effective then our snap on ferrite beads as this balun which provides a higher choking impedance over a broad frequency range. For most effective results, use another feed line choke (coax noise filter) at the radio. Helps reduce noise floor too by choking off common mode neighborhood noise picked up on outside of coax braid acting as secondary receive antenna
1500 Watt PEP Rated 1:1 CUBE™ Balun for dipoles
Iron powder cores are more stable than ferrites and do not saturate as easily so they are best for tuned circuits, filters, and high power inductors. They come in different “Mixes” for use at different frequencies. For best “Q” use the Mix specified for your frequency.To find the number of turns to give the desired inductance for your coil use the formula below:
Turns = 100 x 
Toroid Dimensions
To order specify core size and mix (e.g. T200A-2). Available in sizes that have µH per 100 turns shown in table.
All iron powder cores are special orders. Please allow one week for shipment after order received.
The iron powder cores shown in the above tables are primarily used for either high power feed line chokes for common mode current reduction or for 4:1 and 9;1 very high power transmission line transformers.
For high power feed line chokes, choose the inside diameter of the iron powder core closest to the transmission line outside diameter and use 6-20 cores at the junction with the antenna feed.
For 4:1 (50/200 or 75/300 ohm) transmission line transformers in the range of 1.8-30 Mhz, select the size appropriate for the power level as follows:
T200A x 2 = 1.5KW
T300A x 2 = 2.5KW
T400A x 2 = 5KW
Use Mix 2 for all the above transmission line transformers. Fully assembled and enclosed units are available for each of the power levels. Click HERE for information.
4:1 transmission line transformers using iron powder cores are typically used for ladder line to 50 ohm coax connections
For .1 – 2 Mhz wide band transformers use Mix 26 which has a higher permeability and requires less turns to achieve a given inductance. Mix 2 has almost constant permeability from 1-30 Mhz. Mix 26 has an initial permeability of 75 at .1 Mhz and gradually decreases to about 10 at 30 Mhz. For high power AM broadcast range (.5-1.7 Mhz) transformer, use Mix 26 to reduce the turn count.
Minimum order for iron powder cores is $50
Shipping on larger cores in quantity may be more than $10 – email/call for quote.