<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div><span class="Apple-tab-span" style="white-space:pre"> </span>On Oct 27, 2013, at 1:28 PM, Steve Burgess wrote:</div><div><br></div><div>> Would anyone care to offer a short explanation of the rotary transformer arrangements in Ampex Quad head assemblies?</div></div><div><br></div><div><span class="Apple-tab-span" style="white-space:pre"> </span>I offer:</div><div><br></div><div><span class="Apple-tab-span" style="white-space:pre"> </span>Pretty simple, really. It's a coil inside of a coil. The inside coil is attached to the armature of the head wheel and spins with it. Each 'armature' coil is connected to one of the moving video heads. Each outer coil is a ring that surrounds an 'armature' coil and is fixed in place as part of the unit. You can see the wires at the center of the photo coming from the outer coils. The wires connected to the posts on blue insulator connect the 4 heads to the 'armature' or inner coils. The coil sets are arranged side by side along the length of the armature. Though they are operationally simple, what makes them so difficult to make is that the mechanical tolerances are very tight. The inner and outer coils must be very close together yet not touch in order for there to be adequate induction from each head. This is really hard to do even at lower frequencies and even harder to do with RF.</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>I am not a quad head expert. This is only what I have observed from years of reading Broadcast Engineering. ;)</div><br><div>
<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-variant: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-variant: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-tab-span" style="white-space: pre; "> </span>Dennis Degan, Video Editor-Consultant-Knowledge Bank<br><span class="Apple-tab-span" style="white-space: pre; "> </span> NBC Today Show, New York<br><br></div></span></span>
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