Xref: utzoo rec.ham-radio:4046 sci.electronics:2277
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From: sfaber@ihlpg.ATT.COM (Faber)
Newsgroups: rec.ham-radio,sci.electronics
Subject: Re: build-it-yourself EPROM erasers
Message-ID: <4878@ihlpg.ATT.COM>
Date: 20 Feb 88 00:02:17 GMT
References: <8802091255.AA23298@ucbvax.Berkeley.EDU> <12@ucsd.EDU> <3709@ihlpf.ATT.COM>
Organization: AT&T Bell Laboratories - Naperville, Illinois
Lines: 21
Summary: sunlamps as EPROM erasers

> Not really true.  253.7 nanometers just happens to be the primary wavelength
> of the short-wave UV emitted by the typical lamps used for this application.
> 
> What this spec really means is that you can't use long-wave UV lamps (like
> black lights, or mercury-vapor sun lamps) to do the job.  It also means that
> you can't put ordinary glass or plastic in the light path either.  Only
> special materials, such as fused quartz or some boro-silicate glasses have
> the necessary transmissivity at that particular wavelength.

I bought an old sunlamp at a garage sale that had a quartz tube with
a drop of Hg and no electrodes.  It was excited by rf from a tube
oscillator in the base of the lamp.  These work great as EPROM
erasers.  Mine erases a row of EPROMS the length of the tube (~7")
in about 10 minutes.  These lamps were made in Chicago and sold in
the 1940s or 50s I think. 
	The inner quartz tubes from broken mercury vapor street lights
or newer sunlamps will also work (these contain electrodes) and may
be excited with a fluorescent light ballast.  In general if you can 
smell ozone from your lamp, you probably have a good source of short
wavelength UV.
			Steve N9FYX