MINI-BALUN Features:
- Uses proprietary Multi-Turn ferrite technology for maximum choking (up to -38 dB common mode noise rejection) and maximum bandwidth
- 500 Watts PEP, 50 ohm SO-239 connectors In, Dual Side Stud Output, 1.8-61 MHz (usable to 100 MHz) - AKA 1:1 BALUN
- Works for all coax fed antennas from 1.8-61 MHz (160-6 meters) - excellent for multi-band beam interface, G5RV/ZS6BKW or Flag Pole OCF antennas fed with ladder line.
- 2-5 times more common mode noise rejection, wider bandwidth and higher power then competing isolators
MINI-CHOKER feed line chokes are used to suppress common mode current carried on the outside of the coax braid which is often responsible for receiver noise and RFI in the receiver/transmitter. These chokes are very useful for suppressing RFI common mode current at the antenna feed point, at 1/2 wavelength intervals along the coax feed line and also at the entrance to the radio station.
This choke has a SO-239 input and 1/4" top studs output.
For Higher Power needs use our MAXI-CHOKER with dual stud outputs in 1.5KW or 3KW version part# MC-1-1500LL, MC-1-3000LL
If you need a unbalanced output (SO239 output) instead of a balanced stud output, see MC-1-500 with SO239 output and input..
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:
- No more RFI displayed on the monitors.
- Radio not acting up or turning off.
- The SWR at 160/80 meter is 1.2:1
- No antenna tuner required. (radio goes to Bypass automatically.)
- Worst SWR is on 10 meter with a 2:1 but still usable, with antenna tuner 1.5.
- One happy OCFD user!
Thanks to Palomar Engineers design and engineering for solving this issue.
73, Ernest – W4EG