ASSEMBLED COAX FEED LINE CHOKES
Many customers have requested an assembled sleeve unun or balun 1/4" size cable and we have one all completed with shrink tubing and PL-259 end connectors or open ended on one end for a balanced connection such as a beam, dipole, etc.
All you need to add are 2 barrel connectors (Part # DFBC-1) to insert into your coax cable. For best results add one feed line choke at the antenna to keep the RF on the antenna and another feed line choke at the station entrance to reduce the common mode noise picked up by the antenna braid and fed into the station. Rated 500 watts from 50-450 MHz into 1:1 SWR load. Common Mode Rejection Ratio up to 20 dB (over 3 "S" units) - see graph for specifics..
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