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<DIV>Hi Sandy</DIV>
<DIV> </DIV>
<DIV>I have the same problem on my SB610 which I suspect is due to out of
tolerance resistors around the tube voltage divider circuits. Heath never
provided any form of astigmatism control on those scopes so that meant that some
of the control voltage divider resistors had to be 'averaged' for best focus.
The resistors have probably aged upwards over the years so a good idea to check
them all with a meter.</DIV>
<DIV> </DIV>
<DIV>The later scopes like the SB614 had an astigmatism control so you could use
that information to add one to your SB610 with a new preset on the rear
panel.</DIV>
<DIV> </DIV>
<DIV><FONT lang=0 size=2 face=Arial FAMILY="SANSSERIF"
PTSIZE="10">73<BR></FONT><FONT lang=0 color=#0000ff size=4 face=Arial
FAMILY="SANSSERIF" PTSIZE="14"><I><BR>Bob</FONT><FONT lang=0 color=#000000
size=2 face=Arial FAMILY="SANSSERIF" PTSIZE="10"></I><BR>Bob F Burns G3OOU<BR>C
Eng, FIET, MSE<BR>G-QRP 6907<BR>Secretary of Crystal Palace Radio &
Electronics Club: www.g3oou.co.uk<BR>Technical web site:
www.qsl.net/g3oou<BR>@BobFBurns on Twitter: http://twitter.com/BobFBurns
<DIV> </DIV>
<DIV>
<DIV>In a message dated 28/10/2013 15:18:31 GMT Standard Time, ac1wye@gmail.com
writes:</DIV>
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<DIV class=gmail_default style="FONT-SIZE: large; COLOR: rgb(0,0,255)"><I>Hi,
folks,<BR><BR></I></DIV>
<DIV class=gmail_default style="FONT-SIZE: large; COLOR: rgb(0,0,255)"><I>I've
been using my '610 for a long time and it's always been reliable, especially
after I recapped it.<BR><BR></I></DIV>
<DIV class=gmail_default style="FONT-SIZE: large; COLOR: rgb(0,0,255)"><I>I'm
wondering about something. For those who run these, have you ever noticed how
the trace line can be focused real sharp in the center and it gets out of
focus at the edges? Not by a whole lot, but it's noticeable.<BR><BR></I></DIV>
<DIV class=gmail_default style="FONT-SIZE: large; COLOR: rgb(0,0,255)"><I>I
also have a HO-10 I've rebuilt and I use that on my bench with my dummy load
for testing. The horizontal trace on that is clean all the way across once the
focus is set.<BR><BR></I></DIV>
<DIV class=gmail_default style="FONT-SIZE: large; COLOR: rgb(0,0,255)"><I>Is
there something I need to get into and check on the '610, maybe an out-of-spec
resistor(s) or something else in the Focus circuit? Anybody have a thought on
this?<BR><BR></I></DIV>
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<DIV><SPAN style="FONT-FAMILY: arial,helvetica,sans-serif"><FONT size=4><SPAN
style="COLOR: rgb(0,0,255)">
<DIV class=gmail_default
style="FONT-SIZE: large; COLOR: rgb(0,0,255); DISPLAY: inline">Thanks es
73, Sandy AC1Y</DIV><BR><BR></SPAN></FONT></SPAN></DIV><SPAN
style="FONT-FAMILY: arial,helvetica,sans-serif"><FONT size=4><SPAN
style="COLOR: rgb(0,0,255)">Alexander N. Gerli,
Sr.<BR></SPAN></FONT></SPAN></DIV><SPAN
style="FONT-FAMILY: arial,helvetica,sans-serif"><FONT size=4><SPAN
style="COLOR: rgb(0,0,255)">548 Allred Mill
Road<BR></SPAN></FONT></SPAN></DIV><SPAN
style="FONT-FAMILY: arial,helvetica,sans-serif"><FONT size=4><SPAN
style="COLOR: rgb(0,0,255)">Mount Airy, NC
27030-2202<BR><BR></SPAN></FONT></SPAN></DIV><SPAN
style="FONT-FAMILY: arial,helvetica,sans-serif"><FONT size=4><SPAN
style="COLOR: rgb(0,0,255)">Scotsmen walk about 900 miles each
year.<BR></SPAN></FONT></SPAN></DIV><SPAN
style="FONT-FAMILY: arial,helvetica,sans-serif"><FONT size=4><SPAN
style="COLOR: rgb(0,0,255)">A Scotsman drinks around 45 gallons of Whisky a
year.<BR></SPAN></FONT></SPAN></DIV><FONT size=4><FONT size=4><FONT
size=4><FONT size=4><FONT size=4><FONT size=4><FONT size=4><FONT size=4><FONT
size=4><FONT size=4><FONT size=4><FONT size=4><SPAN
style="FONT-FAMILY: arial,helvetica,sans-serif"><SPAN
style="COLOR: rgb(0,0,255)">Scotsmen get about 20 Miles Per
Gallon.</SPAN></SPAN><BR></FONT></FONT></FONT></FONT></FONT></FONT></FONT></FONT></FONT></FONT></FONT></FONT></DIV></DIV></DIV><BR><BR>_______________________________________________<BR>Heath
mailing
list<BR>Heath@puck.nether.net<BR>https://puck.nether.net/mailman/listinfo/heath<BR></FONT></BLOCKQUOTE></DIV></FONT></DIV></FONT></BODY></HTML>