Off Center Fed (OCF) Dipole Baluns

3182280066 - Off Center Fed (OCF) Dipole Baluns
+3

50:200 (4:1) CUBE™ Current Balun, 1.8-61 MHz, 1.5KW - Loop, OCF, Folded Dipole useful to 200 MHz

CB-4-1500EB
$124.95
In stock
1
Product Details
MPN: CB-4-1500
Country/Region of Manufacture: USA
Type: Balun
Input ohms/Output ohms: 50 in, 200 out
Frequency Range < 2:1 SWR (MHz): 1-31
PEP Power Rating (watts): 1500
Enclosure Size: 4" x4" x 2"
Weight (pounds): 2
Antenna Compatability: Dipoles: Extended double zepp, folded 2 wire, off center fed (OCF); Loops: Horizontal, vertical - coax fed

The CB-4-1500 balun is a multi-core current balun with an enclosure box. Input is via SO-239 coax connector and output can be top studs (for ladder line) or side eye hooks (2) and top eye hook used as a halyard hoist for supporting your wire antenna. Rated 1500 Watts PEP Watts from 1.8-61 MHz (see SWR graph).

This transformer requires a feed line choke to isolate the coax feed line from the antenna. A coax noise filter at the radio end of the coax is also recommended to reduce coax cable common mode noise.is also recommended.

Useful on these type of antennas:

Dipole, double extended
Dipole, linear load, ladder line fed
Dipole, long, non-resonant
Dipole, off-center fed (OCF)
Dipole, snake type, ladder line fed
Long wire with ground system
Multi-band, remote balun


Useful out to 200 MHZ under 2:1 SWR (see swr graph)

Need a 4:1 and 1:1 HYBRID balun? Check out our CB-4-1-1500/5000 with feedline choke built into same box as impedance transformer for ease of installation!


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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