Off Center Fed (OCF) Dipole Baluns

50:600 ohm, (12:1) CUBE™ Balun/Unun, 1.8-31 MHz Balun/Unun, RX Only/1KW/2KW/3KW PEP, T2FD, Rhombic, End Fed, Flagpole

CB-12-1000TS
$119.95
In stock
1
Product Details
Country/Region of Manufacture: United States
Type: New
Input ohms/Output ohms: 50 in/600 out balanced (balun) or unbalunced (unun)
Frequency Range < 2:1 SWR (MHz): 1.8-31
PEP Power Rating (watts): RX only/1000/2000/3000
Insertion Loss (dB): < .1 dB
Input Connector: SO-239
Hardware Type: Stainless Steel
Enclosure Size: 4 x 4 x 2, 3KW = 4 X 4 x 4
Weight (pounds): 2


HF 12:1 Impedance Transformers

12:1 Baluns are useful transformers for 600 ohm balanced loads the impedance at the end of the feed line is 600 ohms (1/2 wavelength feed line), or high impedance feeds for rhombic, T2FD and traveling wave antennas.

12:1 Ununs are useful between coax and long wires with a load impedance near 600 ohms like a beverage antenna. Shortwave listener antennas also can benefit with the 12:1 unun and it may provide a better match than 9:1 ununs – this means quieter noise levels and stronger signals so you can hear distance stations easier.

For end fed antennas, use a 9:1 unun or 12:1 unun - also available in the "Bullet" antenna end fed style (Bullet-12U-500)

Receive only baluns/ununs are rated for 100 watts PEP

All enclosure boxes have 2 side flanges with 1/4" holes.

All of these products are made to order and typical production time is 10 days depending on quantity.

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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