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<DIV>I've changed the subject title since this no longer relates specifically to
RCA headwheels.</DIV>
<DIV> </DIV>
<DIV>After posting the Spin Physics pictures, I noticed the patent number on the
label and looked it up. This particular patent concerns the method of
manufacturing the ferrite heads, but a cross index shows that Spin Physics
received 29 patents, mostly related to magnetic heads, but also including
drop-out compensation, use of field stores for synchronizing non-synchoronus
signals, a capstanless transport, and among other things, an apparatus for
controlling exposure of a solid state image sensor array.</DIV>
<DIV> </DIV>
<DIV>But most interesting is patent # 4040110 which applies specifically to quad
headwheels and involves the addition of ceramic surfaces to both the
headwheel and the vacuum guide in order to extend their life and take advantage
of an anticipated 1500 hour head life. The patent was granted in Aug of
'77. Does anyone know if such a product with the ceramic material was ever
offered?</DIV>
<DIV> </DIV>
<DIV>Don Norwood<BR>Digitrak Communications, Inc.<BR><A
href="http://www.digitrakcom.com">www.digitrakcom.com</A></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="FONT: 10pt arial; BACKGROUND: #e4e4e4; font-color: black"><B>From:</B>
<A title=dwnorwood@embarqmail.com href="mailto:dwnorwood@embarqmail.com">Don
Norwood</A> <BR></DIV><BR>
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<DIV>Hi Dale:</DIV>
<DIV> </DIV>
<DIV>I have a Spin refurbished MK-10 in use at the moment. The
association with Kodak is shown on the label. They did use ferrite
heads, and they supplied a special set of instructions regarding how to safely
measure tip projection. Here are a couple of pics of the
head.......</DIV>
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