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. |
| NORTH
COUNTRY RADIO |
| PO
Box 200, Hartford NY 12838-0200 |
| EMAIL:
support@northcountryradio.com Tel
518-854-9280 Internet
http://www.northcountryradio.com |