Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!husc6!hao!oddjob!gargoyle!ihnp4!ihuxz!parnass From: parnass@ihuxz.ATT.COM (Bob Parnass, AJ9S) Newsgroups: sci.electronics Subject: Re: if transformer? (carrier current intercoms) Message-ID: <2315@ihuxz.ATT.COM> Date: Tue, 22-Sep-87 20:18:54 EDT Article-I.D.: ihuxz.2315 Posted: Tue Sep 22 20:18:54 1987 Date-Received: Fri, 25-Sep-87 01:53:20 EDT References: Organization: AT&T Bell Laboratories - Naperville, Illinois Lines: 39 Summary: carrier current xmsn ok In article , sr16+@andrew.cmu.edu (Seth Benjamin Rothenberg) writes: > I am trying to build a circuit ..., but > I am not sure it is legal now. It uses 'i-f transformers' to transmit > an audio signal over an AC line at 400KHz. The Radio Shack > salesman near me said that the FCC now allows only 46-49Mega Hz > for this type of stuff. Is this true? Carrier current transmission, if done in compliance with FCC regulations is still legal. Here is a partial list of wireless intercoms and their transmission frequencies (in MHz). Several of these models are in production now: intercom, wireless, Allied Knight-Kit [KG-225]____________ 0.1360____- " " 0.2150____- intercom, wireless, Heathkit, fm [GD-1114]___________ 0.2820____- intercom, wireless, Lafayette, fm [FM-50]_____________ 0.1600____ch C " " 0.2000____ch B " " 0.2400____ch A intercom, wireless, Radio Shack, power 50 mw, fm [43-212A]___________ 0.1600____ch B " " 0.2000____ch A " " 0.2300____ch C " [43-214]____________ 0.1600____ch B " " 0.2000____ch A " [43-218]____________ 0.1600____ch B " " 0.2000____ch A " " 0.2300____ch C intercom, wireless, Tele-Tender, power 50 mw, fm [Comm-Call 300]_____ 0.2000____ch A " " 0.2300____ch B " " 0.2600____ch C -- ===-===-===-===-===-===-===-===-===-===-===-===-===-===-===-===-===-===-===-=== Bob Parnass, Bell Telephone Laboratories - ihnp4!ihuxz!parnass - (312)979-5414