---- July 23rd 2024 ----

CAGE Code: 5DME2
ITAR Registration Code: M28889
Call: 1 (800) 377-3244
Monday to Friday 8 A.M. - 5 P.M. (Pacific Time)
E-mail questions and requirements to: sales@coilws.com

Pricing is subject to change depending on product availability and backorders.
*Please Note: Items without price are listed for CWS' capability purposes.


Antenna windings on ferrite rod and phenolic.

Antenna Windings on Ferrite Rod
Antenna Winding on Phenolic

Rods, bars and slugs are commonly used in antenna application where narrow band is required. Rods, bars and slugs can be mde from ferrite, iron powder or phenolic ( free air). Ferrite rods and bars are the most popular type. Ferrite rods are available in standardized diameter and lengths. The diameters are from 1/8" ( 3 mm) to 3/4" ( 19 mm). CWS stocks one of the most extensive range of rods in the industries, in the following diameters and length:

Diameters: 0.25", 0.37", 0.5". Length: 2", 3", 4" 7.5"

Other sizes and length are also available on request. We can cut any of the above rods to any required length. We can also machine rods down to any required diameter. The standard rods are available in NiZn material with a permeability of 125 or MnZn materials with a permeability of 800. Other permeabilities are also available. Please call us for more details. CWS also sells raw rods without any windings. To purchase rods, please call us directly, or purchased through the internet by visiting www.cwsbytemark.com. The 125 materials rods (Material 61) are widely used for commercial AM ( 550 Khz to 1600 Khz) radio antenna and by amateur radio operators ( 3 Mhz to 30 Mhz). The 800 materials (Material 33) is more suitable for lower freqeuncy operations ( 100 Khz to 1 Mhz).

Rods are also widely used in choke application.

The 800 permeability ( #33) rods are used in the following:

1) To filter out the emi noise in the 3.75 Mhz to 7.5 Mhz range ( 40 to 80 meters band)

2) As chokes in speaker cross over networks.

The 125 permeability ( #61) rods are most suitable for filtering emi noise in the 7.5 Mhz to 30 Mhz range ( 10 to 40 meters band). Due to the open magnetic structure of the rods, significant current can be tolerated before the rods saturates.

Application of Rods as Antenna

As antennas, the 800 permeability rods are suitable in 100 to 1000 Khz ( 1 Mhz) range. The 125 permeability rods are suitable in 550 Khz to 1600 Khz ( 1.6 Mhz). The 40 permeability rods are suitable in 30 Mhz range. The 20 permeability rods are suitable in 150 Mhz range. As the core's permeability reduces, the suitable operating frequency increases. Coils wound on phenolic which is essentially an air coil will provide the highest operating frequency. In an antenna application, the Q is an important factor to achieve a narrow band. To achieve high Q, the interwinding capacitance at high frequencies must be minimized. Experimentations show that the best Q is obtained when the coils are wound with one wire diameter spacing between the turns, rather than being closely wound and when the coil is lumped at the center of the rod. Experiments also show that spacing the coils over the entire length of the rod ( with the same number of turns) will also produce a good Q. In this case, when the entire rod lengths are used, the spacing will be greater than one wire diameter apart, and so the inter-winding capactance is the lowest. Use of Litz wire will produce higher Q over the solid wire with the same gauge.

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Disclaimer: Coil Winding Specialist, Inc., its affiliates, agents, and employees acting on behalf of Coil Winding Specialist, Inc. (collectively, CWS) disclaim any and all liability for any errors, inaccuracies or incompleteness contained herein or in any other disclosure relating to any product. CWS reserves the right at any time and from time to time to make changes to design, technical specification, or construction of any product listed on this website without notice. CWS also reserves the right to discontinue or limit sale of any product or service available throughout this website on temporary or permanently basis without notice. CWS highly recommends customers not to use its products offered on this website for inappropriate use and applications. Products should be tested for its suitability by prospective customers in all possible applications and conditions. Customers using or selling CWS products for use in other than recommended applications do so entirely at their own risk and agree to fully indemnify CWS from any damages arising or resulting from such use or sale.

WARNING: This product can expose you to chemicals which is [are] known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go towww.P65Warnings.ca.gov.

Any Comments, Suggestions or Questions? Contact us!
Email: sales@coilws.com
CWS 353 West Grove Ave. Orange, California 92865
Call us Toll Free: 1-800-679-3184 or 1 (800) 377-3244

Tel: (714) 279-9010, Fax: (714) 279-9482

Copyright 2008, Coil Winding Specialist, Inc
Updated July, 2013

CAGE Code: 5DME2(Registered with www.ccr.gov)