Model BA-1-1000 is a 1:1 balun kit used to translate a 50 ohm Common mode impedance peaks With a matched 50 ohm load the SWR over the frequency range 1.8 to 61 Ba-1-1000 1:1 Balun/Unun 1KW PEP 1-61 Mhz The kit consists of a F140 ferrite toroidal core, enamel insulated Add a SO-239 Kit on output side to create a 1:1 unun (coax to coax line isolator) or add studs for a balun for use with dipole or beam antenna. Use the recommwnded CB-Box-1 for a convenient enclosure.1:1 Current Balun
unbalanced input to 50 ohms unbalanced at power levels up to 1000 watts
PEP/100 watts continuous when used with a matched load. With a matched
load the SWR will not exceed 1.5 over the frequency range 1.8 to 61 MHz.
1,000 PEP watt rating on a 25% duty cycle. Will sustain about 100 watts RTTY or FT8 at 6 meters. (for higher power use the BA-1-1500 with 6-8 turns for higher frequencies).
around 3,500 ohms at 10Mmhz.
MHz is shown in the following table measured with an AIM 4170 network
analyzer. Notice that the conversion from 50 to 50 ohms is very
consistent from 1.8-61 MHz and SWR is less than 1.3:1 over the range
allowing easy tuning by most radio internal antenna tuners or an
external tuner.
wire, a SO-239 connector with stainless steel hardware, and an
illustrated instruction manual with directions to connect the kit as a 1
to 1 balun/unun (unbalanced coax to unbalanced antenna or balanced
antenna like a dipole). Balun assembly time takes about an hour and is a
fun learning process.
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.