Return-Path: Received: (qmail 15435 invoked from network); 12 Nov 2002 18:56:34 -0000 Received: from murphys.services.quay.plus.net (212.159.14.225) by mailstore with SMTP; 12 Nov 2002 18:56:34 -0000 Received: (qmail 13985 invoked from network); 12 Nov 2002 18:58:47 -0000 Received: from post.thorcom.com (193.82.116.70) by murphys.services.quay.plus.net with SMTP; 12 Nov 2002 18:58:47 -0000 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.10) id 18BgEW-0001sc-00 for rsgb_lf_group-outgoing@blacksheep.org; Tue, 12 Nov 2002 18:57:56 +0000 Received: from [194.73.73.93] (helo=rhenium) by post.thorcom.com with esmtp (Exim 4.10) id 18BgEW-0001sT-00 for rsgb_lf_group@blacksheep.org; Tue, 12 Nov 2002 18:57:56 +0000 Received: from host213-122-188-143.in-addr.btopenworld.com ([213.122.188.143] helo=presario-1920) by rhenium with smtp (Exim 3.22 #15) id 18BgET-0003Uy-00 for rsgb_lf_group@blacksheep.org; Tue, 12 Nov 2002 18:57:53 +0000 From: "John W Gould" To: rsgb_lf_group@blacksheep.org Date: Tue, 12 Nov 2002 19:02:07 -0000 Message-ID: MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0) X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Importance: Normal In-reply-to: <000f01c28a7a$436f3540$045bfea9@RSGB613192> Subject: LF: Puzzles Content-Type: text/html; charset=windows-1252 X-Spam-Status: No, hits=0.7 required=5.0tests=HTML_FONT_COLOR_BLUE,IN_REP_TO,MAILTO_LINK, SPAM_PHRASE_03_05,USER_AGENT_OUTLOOKversion=2.42 Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Content-transfer-encoding: 8bit
Fine!  I personally don't mind as I find them interesting - the question is do the majority of the reflector users mind the scope of the reflector to broaden to include such technical intrigues?  I must admit that it is better than spam and helps to keep the brain going between M-Class flares and other discussions more relevant to LF.... I'm happy to change the unwritten scope for the reflector if we don't otherwise have any serious dissenters, so (brief) comments please either way ...
 
73 John, G3WKL 
-----Original Message-----
From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org]On Behalf Of Andy talbot
Sent: Tuesday, November 12, 2002 18:34
To: rsgb_lf_group@blacksheep.org
Cc: ME Work
Subject: LF: Re: Tuesday's riddle

Right, done it.   Now that's very interesting !!!!!!
 
Exactly as you specified, even down to the same 2N2222 device. The B-E junction breaks down at 7.56V,   ie. Vbe = (minus) -7.56V  With a DVM, 10M input resistance, Vcb = (plus) +0.35V   almost as if it is acting as a voltage inverter, no wonder you ripped the can apart.  That shouldn't be, BUT...
 
The tunnelling (or whatever the current carriers do in a zener) are probably wizzing across the B-E junction and hitting the C-B junction, then overshooting and slowing down or something, so generating a voltage.  Just inspired guessing.  Any solid state physicists out there ?....   
 
How can anyone want puzles like this removed from the reflector John ?
 
Andy  G4JNT
 
 
 
----- Original Message -----
Sent: Monday, November 11, 2002 7:58 PM
Subject: LF: Tuesday's riddle

Hi group,

this little experiment was pointed out to me by Ralph, DL2NDO a few years ago:

You need an ordinary NPN transistor (eg. 2N2222), a 9V battery, a 1k resistor and a voltmeter. Connect the negative battery terminal to the base and the positive to the emitter, via the resistor. Now predict the voltage drop between collector and base. Can't be too hard...

Then measure it - you'll be surprised. Any explanations? We finally ended up opening the poor transistor's case.

Have fun
Markus, DF6NM