Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site joevax.UUCP Path: utzoo!decvax!bellcore!petrus!magic!joevax!mcg From: mcg@joevax.UUCP (Mark Germain) Newsgroups: net.ham-radio Subject: The Efficacy of ICOM HF Transceivers for Mobile Operation Message-ID: <102@joevax.UUCP> Date: Mon, 28-Oct-85 15:50:36 EST Article-I.D.: joevax.102 Posted: Mon Oct 28 15:50:36 1985 Date-Received: Mon, 28-Oct-85 23:25:42 EST Distribution: na Organization: Bell Communications Research Inc., Morristown, NJ Lines: 16 For the past four years I have used a dedicated IC-720A in a mobile environment and while it's reliability has been excellent, severe design problems with the noise blanker significantly degrades the receiver performance under conditions of crowded bands, presence of moderately strong carriers. The problem is apparently due to back-biasing if the noise detection diode, related to time constants which are too long in the presence of strong signals in the wide passband of first IF. For example, in the presence of strong broadcast carriers on forty meters, even 500 KHz away, ignition pulses to pass through the noise blanker almost completely intact. I am currently looking for another transceiver more suitible for mobile applications, one with a significantly better-designed noise blanker. Does anyone have experience with the more recent ICOM's or the Kenwood line, eg. IC-751, IC-735, 430S ? Mark, KB2IF