Off Center Fed (OCF) Dipole Baluns

25-AMP (Peak) IN-LINE ELECTRONIC FILTER for 12 VOLTS DC, AUTOMOTIVE, RV RFI, ALTERNATOR, PULSE NOISE SUPPRESSION

RFI-N700
$49.95
In stock
1
Product Details
MPN: RFI-N25
Country/Region of Manufacture: USA

PURPOSE:The N-700 is an active electronic noise suppressor that employs a high density, low loss toroid 0.25 mH choke coupled with two power 2N3055 NPN power transistors in a capacitor multiplier configuration. The N-700 is designed to eliminate in-noise for Auto-sound Systems including: Alternator Whine, Fan Humming, ignition pops, etc.N-700 applications include Power Equalizers, Amplifiers, Cellular Phones, CB Radios, Two Way Communication Equipment, Amateur Radio Components, CD Players, and AM/FM Cassette Decks, etc.

FEATURES:The air cooled design of the N-700 filter permits maximum efficiency and effectiveness.The ferrite toroid core of the choke component of the L configuration is responsible for a very high rate of attenuation with very low line losses.The Beta of the power transistors multiples the capacitance to maximize the attenuation of the active filter. There are only three wires needed for the installation of the filter =Filter Input, Filter Output, and the Chassis Ground.The Chassis Ground is required to complete the circuit’s operation.

INSTALLATION:Make sure the noise is in-line before installing any in-line filter.A good confirmation would be to temporarily substitute a 120 VAC to a 12 VDC power supply, or a small 12 Volt motorcycle battery, for the vehicle's electrical system.If the noise goes away when the alternate power supply is connected, then you have a case of in-line noise.

To get optimum results with the N-700, the following directions should be followed:

1.Cut the component's main power lead between the fuse and the component.

2. Connect the GREEN wire to the fuse side of the cut (Source). If no fuse is present, be sure to add a fuse to this connection. Be sure to add a fuse rated at 10 Amps or less to protect the vehicle.

3.Connect the RED wire to the component side (Load). This output lead is also fused to protect the N-700.

4.Connect the BLACK wire to a good chassis ground.The N-700 will not function without a connection to chassis ground.

Practical and easy to install, the N-700 is one of the most versatile and effective filters on the market.

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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