RF FIELD STRENGTH METER
Among the newer RF devices on the consumer market are a wide variety of low power transmitters. These include cellphones, remote control transmitters for garage door openers, carrier current devices, wireless computer peripherals such as mice and keyboards, and PCS devices. Also, many small devices are sold for surveillance use, such as small FM transmitters and other "bugs". 900 MHz wireless video cameras, video transmitters, low power FM stereo transmitters, are also widely used. In addition, ham, CB, and family radio transceivers small enough to fit in a shirtpocket are commonly used. These devices can be used in one form or another as spy devices ("bugs").
This field strength meter can locate "bugs", or other hidden transmitters, can be used to set up and adjust ham and CB antennas, and for testing the operation of remote control and other low power transmitters. The LED Bar graph indicator functions as a meter with 20 steps and can be used for a relative indication or as a comparison device. It will detect the signal produced by very low power remote control transmitters a few feet away, to see if they are "putting out" signal. It is also useful for checking low power Part 15 transmitters, in the FM and AM bands. It will also spot sources of RF and RF interference from devices such as light dimmers, flourescents, and switching supplies. It even checks the electronic car "keys", used by many new cars, for RF output. All of these devices produce RF fields. It is also useful for checking small transmitters such as cell phones, amateur radio handie talkies, family radio (UHF handie talkies), and even CB transmitters. It even checks microwave ovens for excessive leakage and will detect an operating microwave oven 10 to 12 feet away. It can be used to reveal the possible RF hazards from these devices as well.
This meter uses separate low and high frequency preamps and a chopper stabilized amplifier to eliminate drift and the need for zeroing the meter as is necessary with diode detector-op amp designs. The readout is a 20 segment bar graph LED and the sensitivity is -47 dBm, or about 1 millivolt into 50 ohms at 100 MHz. A 2 foot collapsible whip (NC1498 suggested) can be used and the circuit has built in preamps for insuring adequate pickup, even at low frequencies down to 100 kHz, making the meter useful for low power work in the AM broadcast band, the 80 and 160 meter Amateur bands, and the 1750 meter (FCC Part 15) experimenter band, where ordinary diode type meters are very low in sensitivity. Batteries required are 2 ea. 9V transistor radio batteries or 8 ea AA cells
Kit  Price $74.25 USD
Shipping and handling charges are not included in price. (See ORDER FORM).

The kit includes a drilled and etched circuit board, all parts that mount on the PC board, plastic case with hardware and connectors, 9V battery snap connectors, and complete documentation for assembly and test.

Batteries, AA battery holders, and NC1498 antenna are not included as these are optional at the discretion of the builder.

Batteries (AA cells or 9V) should be purchased locally.

A collapsible whip antenna similar to that shown in the photo is available and is sold separately for $14.95 USD.
 
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NORTH COUNTRY RADIO
PO Box 200, Hartford NY 12838-0200
EMAIL: support@northcountryradio.com       Tel 518-854-9280       Internet http://www.northcountryradio.com