Description
Stoddart Electro Systems 91870-2 Dipole Antenna 88-400 MHz EMI RFI NM-30A
The Stoddart Electro Systems 91870-2 is a telescopic half-wave dipole antenna designed for EMI and RFI field measurements across a frequency range of 88 to 400 MHz (labeled on the unit as 88 to 400 MC, using the older megacycle designation). It was manufactured specifically for use with the Stoddart NM-30A Radio Test Set, a classic broadband EMI receiver used in military and commercial electromagnetic compatibility (EMC) testing. The antenna features fully adjustable telescopic elements that allow the operator to tune the antenna's resonant frequency across the coverage band.
Specifications & What's Included
- Manufacturer: Stoddart Electro Systems, Gardena, California
- Part Number: 91870-2
- Type: Telescopic half-wave dipole antenna
- Frequency Range: 88 to 400 MHz (88 to 400 MC)
- Element height over connector: 97 cm
- Telescopic element adjustment range: 18.5 to 94 cm per element
- Tunable coverage via element adjustment: approximately 75 to 385 MHz
- Designed for use with: Stoddart NM-30A Radio Test Set
- Connector: Coaxial connector at base of central mast
- Mounting: Articulating mount with tilt/rotation hardware visible at connector block
- Includes: Antenna only — no cables or accessories
Applications
The Stoddart NM-30A Radio Test Set and its associated antennas were widely used in military and industrial EMC/EMI compliance testing from the 1950s through the 1970s, covering the VHF band that includes FM broadcast frequencies, aviation communications, and early television bands. The 91870-2 dipole serves as the radiating/receiving element for broadband field-strength measurements, allowing engineers to characterize conducted and radiated emissions from electronic equipment under test. Telescopic dipole antennas of this type remain useful today for open-area test site (OATS) measurements, EMC pre-compliance screening, and spectrum survey work in the VHF range, as well as for calibration lab setups where a broadband VHF dipole reference antenna is needed. This particular unit came from an electrical engineer's calibration and product development lab, making it a well-regarded piece of test infrastructure with a known history of professional use.
This Stoddart Electro Systems 91870-2 Dipole Antenna was acquired from a retiring electrical engineer who used it in his calibration and product development lab. It has been visually inspected and appears to be in good used condition. The telescopic elements extend and retract, and the coaxial connector and mounting hardware appear intact as shown in our photos. Normal wear consistent with lab use is present. Please view our photo set and contact us if you have any questions.
Warranty Information
Additional Information
Brand: |
Stoddart Electro Systems |
Model: |
91870-2 |
MPN: |
91870-2 |
Type: |
Telescopic Dipole Antenna |
SKU: |
24700 |
Frequency Range: |
88 to 400 MHz (88 to 400 MC) |
Element Height Over Connector: |
97 cm |
Element Adjustment Range: |
18.5 to 94 cm per element |
Tunable Frequency Coverage: |
Approx. 75 to 385 MHz (via element adjustment) |
Compatible With: |
Stoddart NM-30A Radio Test Set |
Application: |
EMI / RFI Measurement and Analysis |
Connector Type: |
Coaxial (BNC-style, visible in photos) |
Country/Region of Manufacture: |
United States |
Manufacturer Location: |
Gardena, California |
Seller Notes: |
Antenna only — no cables or accessories included. |
Condition Notes: |
This Stoddart 91870-2 Dipole Antenna came from a retiring engineer's calibration lab. Visually inspected and in good used condition. Telescopic elements and connector appear intact. Normal lab wear. Contact us with questions. |
California Prop 65 Warning: |
WARNING: This product can expose you to chemicals including lead and lead compounds, and DEHP (a phthalate), which are known to the State of California to cause cancer and birth defects or other reproductive harm. Go to P65Warnings.ca.gov |