The Tube CAD Journal,Ultra-Linear Output Stages

From: "Saved by Internet Explorer 11" Subject: The Tube CAD Journal,Ultra-Linear Output Stages Date: Wed, 8 Apr 2015 11:45:58 -0700 MIME-Version: 1.0 Content-Type: multipart/related; type="text/html"; boundary="----=_NextPart_000_0065_01D071F1.94984AD0" X-MimeOLE: Produced By Microsoft MimeOLE V6.1.7601.17609 This is a multi-part message in MIME format. ------=_NextPart_000_0065_01D071F1.94984AD0 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Content-Location: http://www.tubecad.com/february2000/page2.html =20 =20 =20 =20 =20 The Tube CAD Journal,Ultra-Linear Output Stages =20 =20

= =20 =20


	Circulation: =20


	Since=20 3/23/99

22057 =20

Solid-State and High Voltage =
=20

This=20 Issue

There is a bumper sticker that = reads:

Audio Rule=20 #1:

Use a = Transistor=20
Go To Jail

It's The=20 Law*

=20 I own this bumper sticker, but not necessarily the = viewpoint.=20 An apostate to most one-and-only true paths, my viewpoint is = closer=20 to "whatever works, works." Yes, transistors and tubes can = go=20 together, if care is taken in the design. Thus, this month = issue=20 covers hybrid designs. Usually, the word "hybrid" evokes = memories of=20 tube front ends driving MOSFET output stages. But those = designs past=20 observed a sharp dividing point where the tubes left off and = the=20 solid-state began. In this issue we will erase that dividing = line,=20 mixing the two technologies in the same stage.
= Remember,=20 if you have a request or suggestion of your own for either = an=20 article topic or circuit, please e-mail: = =20
= =20 =20 Editor=20

*=20 Copyright: Vacuum = Tube=20 Valley
=20


	=20 In general, like oil and water, transistors and high = voltage=20 do not go together well. High voltage is were tubes shine, = as a tube=20 will easily absorb an ultra high voltage pulse and keep on = working,=20 whereas in the presence of high voltage, solid-state devices = seem=20 delicate and fragile in comparison. Although recent advances = in=20 applying safety circuitry internal to solid-state = devices have=20 made them more robust, as little as a shuffle of leather = shoes on a=20 nylon carpet is enough to blow out many ICs and MOSFETs. So = maybe=20 the better clich=E9 is, like a fool and his money, = transistors and=20 high voltages will be parted. Unless, that is, we take many=20 precautions. I have built many solid-state = high=20 voltage regulators, current sources, and DC servos that have = worked=20 perfectly up to the very minute one of the devices blew and = took=20 most of the circuit with it. (DC coupling has its advantages = and its=20 disadvantages and cascading catastrophes is one of them.) = One result=20 that was borne out of the electrical autopsy was that = generic, low=20 performance circuits were much more robust than the more = expensive,=20 tweaky, high performance versions. Do not fool yourself into = thinking that this is somehow analogous to a race car versus = a=20 family station wagon, wherein the race car is actually much = more=20 reliable than the family car, but as it is required to work = at the=20 increased limit of reliability, it breaks down more often. = The tweak=20 circuit is not asked to do any more work (energy over time) = than the=20 stodgy circuit, both only needed to power a preamp or power=20 amplifier, yet the tweaky, high performance version fails = more=20 readily.

In This=20 Issue


	1 7 14 =


	Solid-State and High Voltage Solid-State=20 as AC Circuit Support E-mail Publishing=20 Information Glossary=20 of Audio Terms Glass-Ware.com=20 Articles Classic=20 Magazine articles


	www.tubecad.com Copyright =A9 2000 = GlassWare. All=20 Rights Reserved


	NEXT = >

= ------=_NextPart_000_0065_01D071F1.94984AD0 Content-Type: image/gif Content-Transfer-Encoding: base64 Content-Location: http://www.tubecad.com/february2000/_blnk.gif R0lGODlhAQABAID/AMDAwAAAACH5BAEAAAAALAAAAAABAAEAAAICRAA7Ymxua2ltZyNnaWYNAAA= ------=_NextPart_000_0065_01D071F1.94984AD0 Content-Type: image/gif Content-Transfer-Encoding: base64 Content-Location: http://www.tubecad.com/february2000/img5.gif R0lGODlhjQIZAPf/AAAAAAAAgP///wAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAHtzBCH5BAEBAP8ALAAAAACNAhkA QAj/AAEIHEiwoMGDCBMqXMiwocOHECNKnEixosWLGDNq3Mixo8ePIEOKHHkxgMmTKE8KWMkyZcqV LmPKnElTZUuTLAXYhInzZs2fQIMKlZkzZwCeQ20mXYoS6U+fRX26dDpU6lOdR7EGLdqTqVKgXJdS 9Uq2LFGtXc+arWmUJtKxVdEybbt2q9ysaVvyfKvz5l6sTq3ibQq4b+HBcOsqnov2b165jhEf9qs1 suW7l9UqpWz48UvInSlnPSw5Jt/SnmGKHqz5NGrVkzMvnm06MGnHq2VTTTy1cuzbwDu/xnzXtPGY JJMrX868ufPn0KNLn069unWEtLNr3869u/fv4MOL/x9Pvrz58+jBj70s3PXer5FZE04dO2162rbb k67tefhOxPAR119v80mmn33zufdbf+sVFx9uwCFIIIMRQliYcPddFSCFjxl2oHwFzqSaf6OV+NeH 8U3o1m68ZSiiYC7GKOOMNNaIHl025qjjjjz26OOPQAYp5JBEFmnkkUgmqeSSTDbpJFkthmgebF1B KGGStkFZ3HZRfqXii4yBuKJYWy7WomtPxuUlf9+dmSKZivHmoJa9tSUbang9iGGIVua535JZGggj hyTiSaWYd35WoG5h8RkhiW+KaShohGomKF+MDsjjoZA+yh6MXZ5IaKajrfbli6CVuWmXabbq6quz sVoK66y01mrrrbjmquuuvPbq66/ABivssMQWa+yxyCar7LLMNuvss9BGK+20x8oqa6z1+Vnln0oG GmZ41m4ZqqorkquopJZy+u1RY6LbLqCUWppdpIRxm9S1bOL/axZcdHFqlJ6YQiXugX3q22OW+aka 8IalaruTb7Wd6GBjFVKcmL/7HbrwqR1e6KmHZaKJo50Q93kwxD0pSN+eOHJcL4oLnpbww/J+lipj JI+K8sysqftfaQWbK2SgiZ5Lqso0I/rol0fbi3TTV/KbcbxFn9spxTr/iHHWnV5Z4pg5dy32xeG6 DKbVDD+9tM/yBY0nvIvam/bH9kFttNxt0+1uqbnpHanUdVO9NJtv2zy20C5ufXilhLfbN9d/T3zV zXDWWTLK2z78p2BRpezbxk0S/fnEPGfe89SmvrymlA6r2zKIJms8OqqJ9vuhu416rvrphZ6cKuay D/h652fzJg516Q2+PqvB1DafLObORy/99NRXb/1S12Wv/fbcd+/998pdT2NAADs= ------=_NextPart_000_0065_01D071F1.94984AD0 Content-Type: image/gif Content-Transfer-Encoding: base64 Content-Location: http://www.tubecad.com/february2000/img6.gif R0lGODlhNQBZAPf/AAAAAAABAAEBAQEAAgICAhQWExQUFBUVFRUXFBYWFhcXFxcVGBgWGRgYGBkZ GSkpKSsrKywsLC0tLS4uLi8vLzAwMDIyMjs7Oz09PT8/P3tzBEBAQEFBQUJCQkNDQ0hISEpKSk1N TVNTU1NRVFRWU1VVVVVXVFZWVldXV1hWWVlXWlhYWFlZWVpaWlpcWV1dXV1fXF5eXl9fX19hXmBi X2BgYGFhYWJgY2JiYmNjY2NhZGRkZGVlZWZmZmlnamhoaGtra2xsbG1tbW5ubnFxcXJycnR0dHV1 dXd3d3h4eHl5eXp6ent7e3l+eHt9enx8fH19fX1/fH5+fn9/f399gH6AfYB+gYF/goCAgIGBgYKC goODg4mJiY+Pj5SUlJWVlZaWlpeXl5iYmJqamp6enp+fn6SkpKWlpaenp6imqampqaqqqqurq6ys rK2tra6urq+vr6+tsLCyr7CwsLGxsbOzs7S0tLW1tbi4uLm5ubq6uru7u7y8vL29vb6+vr+/v77A vcG/wsK9w8DAwMHBwcLAw8LCwsPDw8LEwcTExMXFxcbGxsfHx8jIyMnJycrKysvLy83LzszMzM3N zc7Ozs/Pz9HP0tDQ0NHR0dLS0tPT09TW09TU1NXV1dbW1tfX19jY2NnZ2dra2tvb29zc3N3d3d7e 3t/f3+Dg4OHh4eLi4uPj4+Tk5OXl5ebm5ufn5+jo6Onp6erq6uvr6+zs7O3t7e7u7u/v7/Dw8PHx 8fLy8vPz8/P18vT09PX19fb29vf39/f1+Pj4+Pn5+fr6+vv7+/v5/Pz++/z8/P39/f3//P/9//7/ /f7+/v/+/////wAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAHtzBCH5BAEBAP8ALAAAAAA1AFkA QAj/AP8JHEiwoMGDCBMmfMaQYbNiulSRMSSjR48dO3ho3Nhjo8ccPLi8YWLmDR9KunQVa8iSocCG zZ5NMXSoEaRMn0aNQqUKVq1cvoStHAYM16xXrFKV8tTpUqVGgwzB+PNnlK5kz5y1fMlSyqBEjiZh 6kSKFCpWsGjh6iX0WTFhuGjBYoWKFKhOmCY5GjSoBl+ryFq6/NfSK1ixZM2iVct25du4c+vezbu3 719dgQVzbWg47NiyZ9OubftYLl27ePXytUGI0KhcyJrFZPkSa7JkXhV5Tnz2FWNggUvPVXr3kuq+ evSAsnVbM+FnzQAASJAgQgQOHE4E2Z4lCxgwbdrw/w0Ppvv2EyewW6cuHcCaQaQwb30efXr169m3 B+n+Pfz4NuVlcV56HKyXQHvvxZdZQ1xFJ4ABCUggQQccoAAEEPtlIcYXbrBByB8dlqcFEEKUkF4G EUCQgAIACCBAKrcUg9V8gj0jRTNSCPNLQ1OsYooAAHzQBSE14OCeHlPIZgQsskzxzBLADFPjfApV aeWVB9UYk2zD7LJLLyl5GeYuKZVZ5i659NLLL8UsOOVgs8WUTBeJLDJJJqCkkkorsdzSiy++ACOM MMCoCWYtsKgyiiaTSMJIIn+M8MgjrADXDDM0dvXVbqAtNppjcJkmWWqV+TUIYDVuxlBniHUqWmNu hf8aGWqU8WUqqs4Vtmmrir1KmqynTXbcrfLlqulhn/XK2K+QBUuqrZe5ySBhcu5yxFeNiOWJKabs 6RsuQWH1Vi6ywLJKXaRwUusfNaCBRh6XwDLMjNM6JB111mGnHXfegSfeIOSZFwR66kXAnnQJFlsv dPfep69+/Pn7X4ADFnwwAG4cUsous00rG0vNPPEMFphQ0hATeNQhAAEV8PWCDQKYMQcWzyjjgh+N 0OyDJZsAAxxDy2hF23OC+cHjFFMMwhCQMuAwiCA3AMBIKHI0QTNDyRBC75uDObSlQy1t3ZDYLX0M nZaZht3lK6E00kgifMUdN1V0U2XIH4YowgglorT/ksttsnU89DP0JpPLGIR49klOpzTeuCmNoyL5 KaaUMkoonFwCySKEyLBEHGXdkkxgyqQNHSk13eQJKausIostuvSyS1DDCDPML3/2cossrZyCOSSP KGKIDYkk8prZgx/LqbKfxtrsqLVadqrCyXO2a7KhLQvq87QOG22qRK96PW+ewiqcs9ETK23XyvOa ffPnQ+/99Os/o6qN47uqvfOidl/q98ayHrLI56vt9U9Y/6Mf+HQ1QP3BD1jySyCuTIe/BjLPfBD0 H19kcBmy2Y9ozUBGEmjyCElkghM6SQUrYkGLNA1jJcgYRi5mYa66hKIpw6pDHSDRil6sJFP1wRd+ //aVof78K2ACGhiBDIQg+FDvg/ayT77ywy8jTkxgBCuQwQ6EMCdKq0ENmyIRI+YfgAEIi0vcIpDc UxWVADGMQ4RYv8qIxIpp8WJr+IMoYDOfLblIAQeAgAQysAEUCEEIQdBCFr4ghvD8YRBuOKMUhhAE FJxgA3c8QHsG4YlWIOOL/8DKbJJBDJFhIRGEcAgW3vAG6VhgEH+QQQ4EUAY20MwZKrjDIJxEA0RE wha2EAZWlIGp6rHESVgYhScc4hU9AIBlfhiELAFwBjs46Rk7WEQlaBYEUJxiGMPomOCgKJgkJQkm WRhUi2KQg0EQAgcEoIMhsBATLLQJC8nIQjIEN/9O9gmmY59kCQcAgAO/GKIGRLBFMMIJNg++6X5c i6hEJ9qgfzZjdIHB6Cc/2aaNbjQZHd1n/RZYI5AWpXWW04lKR0GKlapUFJYzhSpeUQsfShSipNwF KjKRCDrQoQ1sYMMa1hDUoRr1qEJVgxvgkIdDZGIVxCDGlvp5v2YMwxVfyBskKlGJTpyQE2DVBCc8 AdaygvUSjggeIUqgVD284hW+cOj9kLGKQSyihKLg1ilU4YpZ1AKYwLwFME1zilKAghPAWwS70oAJ TMACGNAp3eBmg4xi/EERkKCEJzyhJ1fQQhe+UFOUXlgoX+zCFrFghSlu+IjN/WEFilAEKnpRv/v/ SeGyYbmEJhqnwrT4iTRFMU0qRiEKrzrqQzNojSgw0wyhLUyAy3sfBrmHQGgpMIDis6B0mXXAZ0lv gsasYHTLx91ZVfe7T/RndsdbQP6Z17vqIyl03UdeA743fQCkIKuwV1/3om9+4H3ueunb3vhpEL21 DZ94Cbw/A583vthdMH8LnMEH5ze8+yVggysM3wsLWMIafiB1O3xd/ebvguX9rwTTS875TnjDI8Zv iTF84u3aV8XWDbB6QezA6XZXxjom55aeYFdHSCJZp3DFq4AhI2QI4xa0QArlQPGJS1CiEYSQZh/6 IIoYnW1otrnoEgZxCCMna0+xsAW4mPwMYsBl/xaxWEUqSIG5vDxig3vYQyViAdlxCuRjyRAGEr7S 2hOmcBVMwsUuXvgMZABjhrBohVKKa2VHZLkG/gnFLYghtpfEpEUJOMADIIBJFGxnCFjAAhg41AZD EEINbPhCFrAQhBKdgEIputgbDHGKq7xRinGsosTMSDElWoyL7vHir4X4MGHT8YxJzCITu6igZTuM ikUcdh2NfUdkJwyUUWQ2tsl4RGjbcdrJrnbygnjtMc6x3MWW9hYR1EZwMwzYzc72s+OdRjzCZxed pg8c803uK0a738j2UHwCjjXpGOAAEoBABzpgSCEAIQtaCAMY2NBqELUhDIpEZApSUDAEFGAALv+q wyNWwQvJPlc6DTAABCDAAQ+UYAhDAAIWtLDqNbThkWtwgxe2gIWck8AEG+hAihiwgABIhxKuyIUx lpG2LCBtCRfAAgZk8AIoQAELHBCBCKTjgBrYoAIUEEAIRMCBKWABAixoQQegMIGXFaEIuhDmlz+8 qmdoARKO+JgU7gAHIFXgD4ewQQwAUBKRJeMFeTDEjXbgiEwAqk1TgugzruAMK3hCE8oIPRb+gAfp tOwPN9CBAM5Ahyoc4xkyMAQkpPCMH2SiFOCME8MFQ3soxAVrU/DEJaQzAVjWoAYCUIMerjYEUaQi C89Iwixw0ZyHKpghNJvC6DjjC1i4qAYgqEF2IG5AADUQwgnMaIYSdEGMG2nfoeFlyDGiEAXoBCIQ znjCbaSTgxoYAhA0AAB5MAlU4Ax8sAfQYXVYAzLyJRhYIS3JACQ5YAODUAgyAACgEAu/cAwxkRly QlHX11DQ8TXQQQhS8ARQ8ARP4AvFQAxj84ITZT8BAQA7 ------=_NextPart_000_0065_01D071F1.94984AD0 Content-Type: image/gif Content-Transfer-Encoding: base64 Content-Location: http://www.tubecad.com/february2000/img7.gif R0lGODlhPwJRAPf/AHtzBAAAqgAA/0hIqm1tqkhI/21t/22Rqm2R/5FtqpFt/5GRqraRqra2qpGR /7a2/7baqrba/9q2qtq2/9raqtra/9r////a/wAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAHtzBCH5BAEBAP8ALAAAAAA/AlEA QAj/AP8JHEiwoMGDCBMqXMiwocOHECNKnEixosWLGDNq3Mixo8ePIEOKHEmypMmTKFOqXMmypcuX GAPIdFCB4YMAAnAGaFjBgMwANWEKPTlhwM8CDyJWIPAz58WbMnMGvVjBaNMBDytA/SlzwdSSBHJy /Tq0rNmzI6GKRcsWpVGxBsxOkDlQbQCsMcUGSJpx60+yHJvubUu4sGGIdndqrMAVqEPGMvkuhCwW 8D/GOXPGZYhZp+WBCiJndKBTc9m5jg9aFV1RJ+uNpWd+FCz58WqaCf0GcJC18WeDkAdzjioTcIUF roUvRK53wIXeryGSFlsb+s/qIhvoFRB47EPtihsm/7d84a1yhrEtM+bN0a7Ul6h3L3Awvz79+4JT R0yO/WJyARLMRlx/Bd2UmX6IEXfeQb5955RD4yWk4G8E4dTAQOUJ9htUETE1VXC77eedSbp199dD pG0mnl4U/tPYAgtpiFAFLVa0wHZ4cXRBADAihFoCE/kkVo4Q6kWgRGH9RKSAOh05EIghStRZcTGO 2FCKD0WIIXEC9JjlggYx5ZpX/4DHE5UI+UUAhFaKVFVykVnA0XRKPkAjjQ34FEABSpkXVQI0PvmA mDPVSCh1xh0X1ZIePWDVkHZO5h6CdU1Y0ZQ6EUDhVmLptVsDd9JogQQPOLBaTmSuJKNSYuY0QKSC Pv+aqkR0yvRqqHnKxCdEbzZHYa0BaHoQZQGoiKJOMzLwk7ANHZCcA88Bh1xjNEUrKKFOHqbtttx2 q5F5NXor7rjklmvuuec6ihMBuKHr7rvwxivvvPTWa++9+Oar77789tsRZLCCdJOX/qKFJ32NDXBf Aw/YWYEF1mJUVcEUV7wtY8YyBF5mEOFkMUq9ookRVOEiZNSNXGWbpZEXJRAbpbOx/PHMbRmILM1D 0ZmTym5F+aSlFvE3Z34g0Ybz0WWVCFubC3FY5IlpJreiZzxlBCd7MBmVsUGkKdmazBsBG56JOzvE nMgOPUoXekwr5PTUaBfU9c1VmtoYz293DJTaEbPICXVJSmvUoEN5xwi2QFrpKRYBfSPE350W4Ilq oy+X/NFbEFkQG88FCQ2bp5aL2CR6B469n6dV/m3T2nA3xpUAA4QuUHQ/60WwQIW77TNBSb7nd9wi uccRsTAfdCOjCmmZEKG7M0hcuOt1ZLOrsh9k4O0V4sS59UC3XrxtpU1gktFnpgwRyr5P1r1Cx3fM 4rDJbe24ABeW76npqhXbUO/fZ696QsipHtIGSMCNcAprBUygAhfIQJI8YAEB+4eBttfAClrwghjM oAb/N8jBDnrwgyAMoQhHqEEBkvCEKExhzRR0oBbGxoUwfCHtVJib1eyJJqGiUalsSBzsKWVazZOI 6xoTw/txxQCgOslx9DTEIyKQhhS7CfKidqCH5A6KVTmQCQcipP4NR0FTlBL5JOIX6pWEeD6E4gUT w6vGpbBWYaTITShIENKsCUQC2GKFDleRJHlNJGNUowYbEBtBRsQ8DxoKZr4ygAPRkUF8tEgZvRg0 4tTPkBkkZBUtoqgmysQAxkGZ6wwwK4EQkogyfN0MuSbDIr6QAhkhViKFQhrk+SWOrXukQmQJJqsN qCLqUqWCmMUZIDYRlNIyYrFKOTtUutB10FrI3F6X/0aCHGeaXGEXLB9ygQPADiK58mSx9NgQ8PzE RMADYPoM9z+C+Kmae6TaLnlktdLBEyU76iXiBjcRz4UNTkzKySW/uEr4NeWeA+EnQ1BWMuUVhHg8 yw89HdK16kEpj/1sW0jKiE5KEuSK82vnQBDgmnClJ01r4ggTOQYTbHpyOwEYqPuu05GrBVSfBeGf Lv/DNpFGDX8Seh9CzvZN0l0oQxoliCYlYpSaTAmXzvPpRwLnS6kaBKSQFGdmnjg1ZR70X1zCaUny ydWE6AyqWS2oHJOzK48IRqYH6eIsIbKj7aQunT9dmUhRI9CVyZR4zjmImY5VHbuI70tWlV5jOmq5 wf+27jfBMU3q1lmhsmIEWGj9SEWVctKZqhVJCq3pL6UZWr125a4eHYhjSQe1CijLfCI6km4IhtWH atU1mXVRUqcqGI4Y07KQ3J5DjbfY5D1vJZHF60Qg85nOCDC5FEwOQr9YGZK8tSFl3CZEmEKdhXIF uAbRnmlhhj7lhlesAkHqoqwiHvTaJaK79QgTcUJO27rGSW+SX/KEOtQj9pSyB0FNfeFXOvDqTidy Oogf/QO6M8FUdkshjoHdOlrCESd21EWvfbubkPyeTqpALNs8g6iQCxwKqLyba0I055qemlcg0+Ls Mh1wn/rYR0wDRlwDHMDdmUTwSjOxT30KUBqFQTCSUCN2XelieFyTaKXHCnJmsH78D6MUYD41vk9T y0dKGgvZy2hy6cvg1Cl2OcBhQkmuxErVO4VRmZM7hvKZZXcTUn4ZP/1bok4QUBPtfLk+JK4hWZCT 5fncJSEHuPKfSXMAGHu1U6k8LSYnTS9O5ZjSmM70pDGTW017+tNQFIxeCnBpUJv61KhOtapXzepW u/rVsI7/taxnTeta2/rWuM61rnfN6177+tfy0nBfUgrsYhtbYuJMtrKHqMsTVsBuooaTtAMtY3JW gGEP2LF9lL2wN5MEMl1e9AJ8Mt1jo8SPxWJYDiNHI+YBJVTsPtipUptCvyDFjQ/Vma2ecmGqlCrS DlD3w0JVKmAhCmRdayGGzX0WzBB7Iac8Z9o8hukQT9isXLkIlIXt4J9c/KFylY2TBaNfhr/EQ1Ys bvkmrV56L8QqW7RZk2Ny34p0836lllBTmm3ykFQldFT1LiZP9fEiwfUx9N3Yoava14uQdFUhURDP ez4Uc1J81cnN+c8pwppG0pTmo0N2bIrez0hSvVtBP7Vu/6buEaYg4Gfx9ZuIM+J1uETd7GffVtpB DaWSr6RwtwR702MZZbJ7luN5R8veeRXkQvMYZowR94K0Yh8efnc+SWyI5ZedWMR2XonAUxvbA4kR q7+Y63jPygOZaGQkI10+jke5bSWPnWvXuIlG9rZt2SVktDLGyI5H/EAIQEHSiNtuOb+qyqlSd5ws fJfoC+yMtOL163yoJwnDtzXd3R8arYbtuHOdWVbZGQDrLexL+27Mvh4Rv6AZccE0o20UXqPjZEb6 M3KUp2qjFTipDPvbYTnPphP4lxWrYVHNN3dp0VsaoTladCyplXU/xX7GlViNVG7LQS1l4U0PVyBF Vkk6cf90FhFirBMYqWdQCjgjsVFuDihPQJZaLOaCBeEnKLZhP+F3BsFQE6E2NagQLWh+AsMlJiiD TVOCk9U/nNKDCRV3VcYdYKcThrdR5rU5rVFhGkGCTlhTJ2hN5oGDHriFs/OAFqaE/gOEVUYcHRhS VFhOKgZkpZOGXeVypVc6Q2iGBrFaR/gbEdcl7fV5gqMgGOgmn/UPZ0NfXGeFGTEtmQGHeUGBHcYV nRZ+TSGC8WSHBYGHFWiGomSEjrMX5VE6NVJbUcMb7idEYgg4ClKHLieKZfg9IPJxpSUQAxCJC3U/ QhFWrsRWhxiColVzbgWGUCJAhUhJnYVdnKhzREgQ8wWnX3xhAc3nRaxoWypCVLJTjA6Uip+TjLlx jJ0og3jicaFTWm8SiGwYiyjhTQGgfdZ0NxmFfoS3Ptk4iIS4fIzXQ+xkiR/FjVEFhJzCOdHxiUqC b9H4M20li3rxYfi4EZpEN/WkjQiBicjIZI1BfJ6Xi1HIEDxEi+1xenDnh60IfgRBgiCZVhomfru4 FvvlkILVht2ogDQCRMj0JbVHctxDhtkDHNk0Uwn/qRHTY5N6tZMSpI/n5ZDJ5VHwaEp8CFakB3rU hhAu80fnN3gYwVc4QY6HpzKqZEKCUZBZBZQDqVut5BpeCEkimIQZA5EmsxvxNnDMI1ynSBILyZKo p5LK55NgaYcyFwCHFVQ+xRQfUZQj+VBVIgAJZh3y2DmIeCljB0hgqHT0s1xL2TlvWYR2CXX/QFJD YoqUSIiloyID6UcwpUoYFYfJt40tthHNtz3IgYGWeRD6xk4c6RE0eJG6cyTcJUCnVF2IlYJrNXNF A4YuQodk1BSM6E6O9BCruZuUsnbus5kGeWEXEAFCORBYohDVl4X3KIcXYXobmZnlYzmtyUr3B5v0 /0YAGmmaTGg2eAUVVjkQ1bd0cqc/FtFygZmShxky8mmYYylzmcVcymkcp5Jb90lmV2eaBBUspHkm 5DSMHbFSxQl30eWbODmZ4cVfCuFN7UmZ6fmIMrGX9qWd6yhhyil8+agkpamGiJeXJVOKDuGgXxSh DpkYCAUZRRcyKMmh4eIXE2aNKjiaFAGYHYFNBPImBUhQOVGc01OkE+qIOBmbUqKItkJHvzWBtDl8 CnJxSWh9DTEBrRIsJ2qf2pkYTjJN1SOkM2IUSppkvKmMjaEAB2aX1JlxpummDhEaUQFP5deU/zAd 5HhNQ1Q6QTZgSwGorrM9gxJlXiUYDhABbjNuY7aWbMApMV1qKw5AATkEAYc6TLWBMEoWqDzhqMJ0 RF6iZ1EmUYkKhZbaEphiQp2UbO1yKfzTRNsTYf8hqmkym0l0HJNKqRiYO3bzTMB1qKF5F3xxHIg0 bX9aoInHEw2zAFAmAPSRbV/6baLCLU+1rNiarRqxkAGgXdr6reBqNmKRoeFarmfnceaaruo6ENMy rev6rqimGwoDc/Barz2HKVHhnPa6r/zar/76rwAbsAI7sARbsCAUEAA7 ------=_NextPart_000_0065_01D071F1.94984AD0 Content-Type: image/gif Content-Transfer-Encoding: base64 Content-Location: http://www.tubecad.com/february2000/img8.gif R0lGODlhjQIDAPf/AHtzBAAAgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAHtzBCH5BAEBAP8ALAAAAACNAgMA QAhmAAMIHEiwoMGDCBMqXMiwocOHECNKnEixosWLGDNq3Mixo8ePIEOKHHnxn8mTKFOqXMmypcuX MGPKnEmzps2bOHPq3Mmzp8+fQIMKHUq0qNGjO0kqXcq0qdOnUKNKnUq1qtWrCAMCADs= ------=_NextPart_000_0065_01D071F1.94984AD0 Content-Type: image/gif Content-Transfer-Encoding: base64 Content-Location: http://www.tubecad.com/february2000/img9.gif R0lGODlhjQICAPf/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAHtzBCH5BAEBAP8ALAAAAACNAgIA QAg8AAEIHEiwoMGDCBMqXMiwocOHECNKnEixosWLGDNq3Mixo8ePIEOKHEmypMmTKFOqXMmypcuX MGPK/BgQADs= ------=_NextPart_000_0065_01D071F1.94984AD0 Content-Type: image/gif Content-Transfer-Encoding: base64 Content-Location: http://www.tubecad.com/february2000/img10.gif R0lGODlhaQAcAPf/AHtzBP///wAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAHtzBCH5BAEBAP8ALAAAAABpABwA QAiKAAMIHEiwoMGDCBMqXMiw4cJ/EB1KnEixosWBEP9d3Mix48SMHkOKHAlypMmTFEuiXMnyoMqW MFm+jEmTZMSaOEXOzMmz4s6eQBv+DEoU4dCiSDHeTMq04NGmRJ9CBSp1Ks+qVnFizUpzK1eYXr/K XCo2aNiyJ8+italxLVWybrXCjdt1Ll2wEAMCADs= ------=_NextPart_000_0065_01D071F1.94984AD0--