The best active monopoles ever made are no longer in production. These are the Stoddart/Singer/Ailtech 95010-1, and the Honeywell model 2825 (I think) . Both these antennas were developed for TEMPEST use originally, and are quite sensitive. The main drawback of an active antenna is reduced dynamic range to broadband signals, and these two antennas dealt with this in two different ways. The Stoddart unit had a special, now obsolete FET that had tremendous dynamic range. Perhaps not coincidentally, I never had a problem with this antenna and ESD damage. The Honeywell unit had a capacitive and therefore frequency independent attenuator between the rod antenna and the FET gate, so that the attenuator, unlike in the EMCO 3301, actually protected the dynamic range of the input FET, instead of just adjusting the output level seen by the spectrum analyzer or EMI receiver.
The Stoddart unit’s amplifier had absolutely flat frequency response, so that the antenna factor is constant at 8 dB from 10 kHz to 40 MHz. I don’t recall the Honeywell antenna factor. The Stoddart antenna calibrated like all Stoddart rods, using a very clever and Stoddart-unique calibration fixture. The EMCO calibration device was one of the problems with the 3301B antenna. You can still find these antennas around, but if you are looking for a new antenna today I would look at the Electro-Metrics EM-6892. I believe this is substantially the same antenna as the old RVA-25. My understanding, you can check with ETS/Lindgren, is that a replacement for the 3301B is either underway or being considered. Ken Javor Phone: (256) 650-5261 ________________________________ From: Julian Jones <[email protected]> List-Post: [email protected] List-Post: [email protected] List-Post: [email protected] Date: Mon, 11 Aug 2008 11:35:52 +0100 To: <[email protected]> Conversation: monopole recommendations Subject: monopole recommendations we need to get a back up for our EMCO 3301, 41 inch rod antenna. looking for recommendations for what other labs are using. I've noted the changes MIL 461F brings with grounding the connector especially. I've almost finalised on the A H systems SAS-550-1B has anyone got / used this one ? any problems to report. Rgds Julian Jones Hursley EMC Services Tel: 023 8027 1111 Mob: 07787 523 607 [email protected] <mailto:[email protected]> <mailto:[email protected]> Unit 16, Brickfield Lane Chandlers Ford EASTLEIGH, Hampshire, SO53 4DP Company Registration 3301279 <mailto:[email protected]> <mailto:[email protected]> __________ Information from ESET NOD32 Antivirus, version of virus signature database 3345 (20080811) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
