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.
Also make sure you connect a good RF ground to the transceiver ground post.
Note to Flex Radio users: Use snap on ferrites for firewire cable, speaker cable and mic cable, Ring ferrites for Antenna output and DC power.
For additional RFI suppression, use a feed line choke at the antenna to suppress common current on the coax feed line – see our store for feed line choke alternatives for use at the antenna.
If you use a linear amplifier we have RFI kits for linear amplifiers that help suppress RFI in your shack or in your neighbor’s house.