Homepage Crypto Spy sets Burst encoders Intercept Index Gürtelpeiler GPO USSR Quante Telefunken RZ-301 HRO AR-88 SX-28 Mason Microtel Scanlock REI Minilock R&S RFT Kolibrie PAN-1000 Covert Radio PC Telex Agencies Manufacturers Donate Kits Shop News Events Wanted Contact Links HE-100 Portable active directional antenna The EH-100 was a set of portable active antennas, developed by Rohde & Schwarz in München (Germany) in the 1980s. The antenna set was used for locating interferences and radio bugs, and was initially developed for use in combination with the EB-100 portable surveillance receiver.   The HE-100 is suitable for all frequencies from 20 MHz to 1 GHZ and consists of a handheld pre-amplifier in the shape of a pistol grip, and three plug-on antenna's. Each of the antennas covers a different frequency range. The pre-amplifier is powered by internal batteries and is activated by pressing a trigger switch in the grip. The three antenna's use the terminated loop principle developed in 1938 by Harold Beverage in the USA [1] [2]. Due to the nature of these antennas they are far less sensitive to signal reflections, especially when used indoors.    For storage and transport, the three antennas are usually packed inside a purpose built executive style briefcase, together with the pistol-grip pre-amplifier, the instruction booklet [3], spare batteries and any other accessories. The antennas cover the following frequency ranges:   20 - 200 MHz 200 - 500 MHz 500 - 1000 MHz The antennas were designed to match the frequency coverage of the EB-100 from 20 MHz to 1 GHz. For most bugs of the 1980s, the largest antenna (20-200 MHz) was used. In practice, the middle antenna (200-500 MHz) could also be used when in close proximity of the transmitter. It made the antenna slightly less sensitive but that was often considered a bonus.    When using the HE-100 in combination with the EB-100 reciver, the field strength meter at the rear of the HE-100 would show the signal strength of the signal, duplicated from the signal strength indicator of the EB-100. The meter could also be used to test the HE-100's batteries.   When the HE-100 antenna and the EB-100 receiver were used in the dark, the meter could be illuminated by pressing a second switch in the pistol grip of the HE-100 (i.e. the lower one). Although the HE-100 antenna was initially designed for use in combination with the EB-100 receiver, it could very well be used with other TSCM devices, such as the Rohde & Schwarz FSH-3 portable spectrum analyser shown here.  More about the FSH-3    The HE-100 antenna was later superceeded by the HE-300 active directional antenna, which has an extended frequency range from 20 MHz to 7.5 GHz. At the lower end, the frequency range can be further extended down to 9 kHz by adding the optional HE-300-HF module.   References US Patent 2247743, Broadband Uni-directional Shortwave Antenna Harold H. Beverage. Filed 10 December 1938. DARC Verlag, Rothammels Antennenbuch ISBN: 3-88692-033-X. 2nd print 2002. p. 269-270. Rohde & Schwarz, Active Directional Antenna HE-100 652.1803.02 (German/English). March 1986. Further information EB-100 portable surveillance receiver PR-100 portable digital receiver FSH-3 portable spectrum analyzer Other Rohde & Schwarz devices on this website Other TSCM equipment Any links shown in red are currently unavailable. If you like this website, why not make a donation? © Copyright 2009-2013, Paul Reuvers & Marc Simons. Last changed: Tuesday, 15 April 2014 - 13:00 CET