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<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt'>Guys,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt'>I am
restoring an Ampex VR2000A quad VTR. I now have E-E signal through the
machine.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt'>In
the Play mode I only have noise coming out of the demod.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt'>I
checked the head assembly modules in back of the machine and found no RF going
into the head amps.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt'>I
know this machine has nuvistors and 6761 tubes so 6.2vac filament voltage is
required. I measured the output of the filament transformer and I only
have 1.3vac in E-E mode and play mode. Measuring the input of the
transformer I have approx 118vac. (see attached pictures)<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt'>I
replaced the filament transformer and have only 1.3vac. I also replaced
K1 located just above the filament transformer, no difference still got 1.3vac.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt'>I do
not have a schematic diagram of the transformer or what is controlling
K1. I do not know if any what role K1 plays in triggering 6.2vac filament
voltage. There is a large cap (C1) located next to K1. (see picture
below) I have no idea what role that plays either.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt'>There
are 4 wires on the primary side of the filament transformer and two wiring on
the secondary that should output the 6.2vac.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt'>Since
I do not have a diagram, I do not understand the operation of generating the
6.2vac filament voltage. What control if any turns on the 6.2vac?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt'>Any
ideas what my problem may be?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt'>Pat <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt'><o:p> </o:p></span></font></p>
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