Model SLO-1/2 family of chokes are for use with ½” coax cable like RG-8, RG-213, 9913, LMR-400 and similar cables up to ½” diameter – works on all cable impedences (50, 62, 75, 90 ohms etc). 80-6 meters.Choose SLO-1/2 (5 beads) or for extended choking, choose SLO-1/2E (10 beads) or for super extended choking choose SLO-1/2SE (15 beads). Select chokes with minimum of 500 ohms at your frequency of interest for best results or upgrade to our CUBE(TM), Super Choker(TM) or Maxi-Choker(TM) chokes up to 10,000 ohms choking. Select 5 bead version for 80-2 meters use; 10 bead version for 160-6 meter use, 15 bead version for even higher choking power on 160-20 meter frequencies. Power rating is same as coax cable used power rating. Protective heat shrink included with beads and instruction manual. Snap On and Slip on Feed line chokes available in sizes to fix cables with outside diameters of 1/4", 3/8", 1/2", 3/4", 1" - check website for other size options. The 5 bead, 1/2" model was previously part # BA-8 The SLO31-1/2-5 is the new name for the old product name BA-8-5, the SLO31-1/2-10 for BA-8-10, etc. Testimonial: KI7AY
1/2″/12.7mm max Cable Size Chokes
Wanted to let you know that I was having a problem with RFI on 40m, but immediately after installing your Slip On Coax Feed Line Choke -1/2"/12.7mm cable, 1.8-300 MHz on a new RG-213 jumper between the IC-9100 and tuner, IT WENT COMPLETELY AWAY!
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.