Path: utzoo!utgpu!water!watmath!clyde!rutgers!ukma!gatech!bloom-beacon!husc6!bbn!uwmcsd1!ig!agate!pasteur!trinity!max
From: max@trinity.uucp (Max Hauser)
Newsgroups: sci.electronics
Subject: Re: Extremely small transmitter - help!
Summary: Hearing-aid batteries
Message-ID: <552@pasteur.Berkeley.Edu>
Date: 5 Feb 88 05:07:45 GMT
References: <1434@obelix.liu.se> <2388@kitty.UUCP>
Sender: news@pasteur.Berkeley.Edu
Reply-To: max@trinity.UUCP (Max Hauser)
Organization: UC Berkeley
Lines: 13

In article <2388@kitty.UUCP> larry@kitty.UUCP (Larry Lippman) writes:
>  ...
>an FM transmitter operating in the 88-108 MHz region which is built around
>a tunnel diode (like a GE 1N3712 or equivalent).  The power supply need be
>only a single 1.3 volt mercury hearing aid battery.  

I agree; I've built these, they're not difficult. The battery is the
largest part. Use eighth-watt or smaller resistors if you use a
voltage divider to bias the diode into its neg-R region.

The neatest thing about the project, of course, if it's a snake
of moderate size, will be tracking the transmitter visually from
the outside ...