2x Ferrite Toroid Core Mix 31, DIY RF Choke, FT240-31, 2.4 inch OD Free Ship
2x Ferrite Toroid Core Mix 31, DIY RF Choke, FT240-31, 2.4 inch OD Free Ship

2x Ferrite Toroid Core Mix 31, DIY RF Choke, FT240-31, 2.4 inch OD Free Ship

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Sale price

FT-240-31 Ferrite Cable Cores 

2.4 inch OD, 1.4 inch ID

Group of 2 Ferrite Cable Toroidal Core, RFI Suppression, Mix 31, 1.4" in ID, 2.4" in OD.

Note: Make your own high choking value, RF Choke

Shipping included in purchase price.

Smarter, stronger and more elegant all-band ham radio antenna option. Your friends, family, and DX totals will agree.


Product Attribute Attribute Value
Ferrite Cable Cores
Ferrite Bead Cores
119 Ohms
35.55 mm (1.4 inches)
61 mm (2.4 inches)
12.7 mm
Brand: Fair-Rite
Frequency: 1 MHz to 300 MHz
Product Type: Ferrite Cable Cores
Shape: Round
Subcategory: Ferrites
Test Frequency: 100 MHz
Type: Round Cable Core
Unit Weight: 4.162328 oz
  • HOA Approved + XYL and neighborhood approved too!
  • No Radials! needed for high-performance
  • Coax Adapter included The feed system uses ladder line at the antenna for the lowest possible loss. Connect your coax and turn on the radio. 
  • Strong, Smart, Elegant design. "Pretty" premium aluminum, No messy stubs, coils, etc.
  • Premium-only, Made in the USA. Double-dipped, double-walled tubing & stainless steel parts.
  • All frequencies 160-6M including WARC, MARS, FEMA, etc.
  • 160M bonus: Try the 20'-24'-28' many report success! 
  • Smart Clean Design, Rugged Materials & Engineering: 80-100 MPH wind rating
  • Best in Class 'as good or better' than any legacy brands 
  • ARRL Antenna Competition Award Winner
  • Featured on Ham Talk Live Ep. 188 "Stealth Antennas & HOA's"
  • >90% and better efficiency across all bands
  • Very Low Losses owing to the feed system
  • Lower Angles than ground-mounted verticals requiring 100+ radials
  • Lower Noise too reported widely 
  • Easy Install: Dig a 3-4' post hole, build antenna (1-hour), dirt or Quik Crete, drop-in (15-20-lbs), plug-in, play radio!
  • Free Shipping in the USA + Deep discounts Worldwide
  • Shipping time: See our Order-Status Page for transparent updates
  • Industry-leading 4-year warranty   
  • New! 5-15 minute build times on the new versions (same Strong, Smart Elegance)

XYL & fussy neighbors approve too. 

That's right, Elegance! Clean lines, smooth premium finish. No ugly stubs, traps, coils, or unsightly elements or 100's of radials to mess with. "They" see an aesthetically pleasing Flagpole, you see 160-6M Real DX.

"So pretty she let me install it in the garden!"

What customers are saying:

  • "Highly Recommended for HOA and CC&R Restricted Ham Radio QTHs." 

  • “So pretty my DX Flagpole Antenna is allowed in my wife’s garden! In the GARDEN!”

  • "4 Band DXCC this summer with my 20' DX Flagpole from my HOA!"

  • "Clean Sweep in November Sweepstakes with my DX Flagpole!"

  • "Got Indonesia (YB) this morning on 40m SSB with 100 watts. Just over 9,000 miles!"

  • "Since I added the Greyline DX Flagpole vertical antenna, I have added over 200 additions to my DXCC Challenge account. I am now right at 900 and hope to complete it in the next few months."

  • "Holds its own vs. taller competitors with no radials & is also stealth!"

  • "The other night I was on 60M and it felt just like the old days, running JA’s from Chicago in the CQWW CW with a 4-1000 Amplifier to a Quad at 80-feet!"

  • "Got Mauritania, Dodecanese, Israel, and Cypress on 80 meters and 4 bands and 3 modes for VP6R on Pitcairn. First Pitcairn since 10 Meter AM contact in the 1960s."

  • "Designed Smarter, Stronger, and more Elegant Aesthetically."

  • "So so many FT8 stations worldwide."

  • "If I can hear it, I can work it and this antenna hears well."

More Customer highlights and Pictures can be found in our Customer Reviews section within the FAQ and the RF Blog.


Q. How does the DXV OCF Antenna compare to other well-known antennas such as the Hy-gain AV-680 and Cushcraft R9:

*The Red inner rings are 80M, blue 40M, green 20M, and orange 10M. 

Q. What's the difference between the Greyline Performance DX vertical-dipoles & DX Flagpoles, 12-16-20-28 to the famed 43'er?

* For 24-foot performance, consider between the 20' and 28' angles and potency projections.

Grounding: As always, when considering your grounding plans, follow the ARRL RF Guidelines.


USA: Free Shipping
DX: Lowest possible cost (USPS, UPS, DHL) ~$25 USD

Learn more about shipping rates in our FAQ's.

Greyline Statement:

We are a small group of "seasoned" radio ops, maybe just like you. This is our passion and we often ask "how can we make this better." We partner with small ham radio owned businesses to bring you something more.

Presenting an HF radio antenna that is an efficient transmit and receive antenna experience across all short wave frequencies, 1.8 MHz to 50 MHz. A Smarter, Stronger and a more Elegant vertical antenna designed for elegance, robust engineering, and higher-performance. More efficient systems offer less loss, more dB's, less noise, more signals, lower angles, deeper DX, and a potent Regional (NVIS) radiation pattern too.

Popular with digital modes requiring rapid frequency hopping (ALE) such as FT8 mode and other Winlink and SDR applications. 

We enjoy talking radio!

Write in or call us to discuss any questions you have. It’s an honor to serve you in this manner. Thank you for the opportunity.

Ham Radio is fun again!

73 Greyline Performance

Customer Reviews

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