NRM-2 Resonance Dip Meter
Thumbnail Picture - Click to enlarge
National RF’s Resonance Dip Meter is a test instrument used to determine the
resonant frequency of a tuned circuit or resonant network, such as an antenna
system. In addition, the unit may function as an RF detector, or a secondary
frequency source. The instrument is analogous to the older vacuum tube “grid
dip meter,” once popular in every electronic laboratory or radio station.
Unique to this updated version is a buffered output that may drive a digital
frequency counter for exact measurement of resonant frequency, or connected to
an oscilloscope to be used as an RF detector and waveform/modulation monitor.
The unit is hand-held and powered by a single replaceable 9-volt battery.
Battery lifetime is estimated to be over one year with average usage. Plug-in
coil sets are provided to provide a useful frequency range from under 1 Mhz to
over 70 Mhz. Each plug-in unit has its own separate analog scale which gives
approximate RF frequency. Exact frequency is determined by the use of an
external frequency counter, not provided with this system.
The instrument is
offered in two configurations in order to meet your technical requirements as
well as pocketbook considerations. Type NRM-2D is the deluxe instrument
set, including a ruggedized carrying and storage case (manufactured by Pelican
Products) and the standard three coil sets, covering the 3.5 MHz to above 40
MHz frequency range. Otherwise, the basic Type NRM-2 instument with one
customer specified coil set is sold to the user. The other coil sets may
be purchased separately, as desired. Additional coil sets are available
to cover frequencies between 1 MHz and 3.5 MHz, as well as from 40 MHz to 70
MHz. These sets are not provided with the deluxe instrument configuration,
and sold separately upon request.
NRM-2 and NRM-2D
Size: NRM-2 Mainframe Body 4 in. X 2.125 in. X 1.75 in. (coil
With coil assembly installed 6.75 inches, overall
Frequency Range: Coil
Set A: 1 MHz to approximately 1.9 MHz
Set B: 1.8
MHz to 3.5 MHz
Coil Set C: 3.5
MHz to 9 MHz
Set D: 7.1
KHz to 19 MHz
Coil Set E: 17
MHz to 43 MHz
Coil Set F: 40
MHz to 70 MHz
(Note: Coil Sets C, D, and E are standard with the deluxe model)
Power Requirements: Single 9-volt Alkaline battery
Controls: Main Tuning RF output/power
Interface: Buffered output via BNC female chassis jack to Frequency Counter or
Oscilloscope, approximately 1/2 Vpp into 1000 ohms
Type NRM-2 (Main-frame plus one customer specified coil set) $219.95
(includes carrying case plus C,D,E coil sets)
Individual coil sets $39.95
must add 7 3/4% sales tax.
Shipping and Handling
extra, dependent on order.
Overseas Customers: Please note that an additional overseas shipping
charge will be applied to your order. National RF will notify you of the exact
amount of shipping to your country via e-mail, after your e-order is placed. The
customer is responsible for all and any customs or tarrif charges applied to your
Form - Contact Us