Off Center Fed (OCF) Dipole Baluns

442283787 - Off Center Fed (OCF) Dipole Baluns
+3

FB102-31 - 1/2" ID, RFI Range 1-300 MHz

FB102-31-1
$3.30
In stock
1
Product Details
MPN: FB102-31
Initial Permeability (@ 10KHz): 1500
Material: MnZn
Max cable size - in/mm: .5/12.6
OD (A) - in/mm: 1.02/25.9
ID (B) - in/mm: .505/12.8
Length (C) - in/mm: 1.125/28.6
Z (ohms per bead - single turn 1 MHz): 31
Z (ohms per bead - single turn 5 MHz): 98
Z (ohms per bead - single turn 10 MHz): 120
Z (ohms per bead - single turn 25 MHz): 205
Z (ohms per bead - single turn 100 MHz): 340
Z ohms (per bead - single turn 250 MHz): 315
Case/Box lot size: 212

Ferrite Slip On Bead, ID = .505in/12.8mm, Mix 31, 1 piece - very useful for making feed line chokes for RG-213 (1/2") coax line.

These beads fit well on 1/2" coax cable and make excellent sleeve chokes (See BA-8-5 for sample graphs pf effectiveness)

212 pieces/case

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Testimonial

Hi Bob,

Radio: Flex-6700 running barefoot -10 to 100 Watts max.
Antenna: MFJ-1216 – 160/80 meter OCFD wire antenna with matching network.
Elevation: Over 60 feet AGL – fully extended.
Installed: Mid November 2013

I operate mainly on the digital modes running less than 50 Watts.  All of the sudden after a few days operating with this antenna, I start to have RFI and my radio was acting up; such as changing bands, SWR changing values, radio failures and turning off. However, when I used my Hy-Gain 18 HT vertical on the same band none of the abnormality occurred.
I contacted MFJ and confirm that what I was noticing was a failure of their “matching network” AKA balun.  They offered no solutions. Then I contacted Palomar Engineers and bought the 1:1 new toroid RF beads.  I called Palomar Engineers and I happened to talked to you directly; regarding the on going issue with the MFJ antenna. I found out that the 1:1 balun was not what I needed (I was miss-informed by MFJ that it was 1:1 matching network.)
You offered to make the required balun 4:1 and the rest is history.

Here are my findings:

  1. No more RFI displayed on the monitors.
  2. Radio not acting up or turning off.
  3. The SWR at 160/80 meter is 1.2:1
  4. No antenna tuner required.  (radio goes to Bypass automatically.)
  5. Worst SWR is on 10 meter with a 2:1 but still usable, with antenna tuner 1.5.
  6. One happy OCFD user!

Thanks to Palomar Engineers design and engineering for solving this issue.

73, Ernest – W4EG