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Safe to powerup without Speaker?
morzh
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#16

12-28-2014, 05:14 PM
Keith

I am not sure what you've done so far, but recap, recarb AND checking your tubes for 1) being what they should be and 2) being functional are the steps you should not skip.
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keith49vj3
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#17

12-28-2014, 05:24 PM
The first thing I did was test my tubes but my bi-focals didn't catch the 7G7 swapped for a 7B7. All of the out of spec resistors have been replaced along with all the paper and electrolytic caps. From now on I will double check all tubes to make sure they are what they should be.
Keith
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Ron Ramirez
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#18

12-28-2014, 05:37 PM
7G7 is a sharp-cutoff pentode; 7B7 is a remote-cutoff pentode. You need a 7B7 for proper AVC action.

7AH7 is the preferred substitute but 7A7, 7H7 and 7T7 will also sub.
http://www.nj7p.info/Tube/SQL/Tube_query.php?Type=7B7
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Ron Ramirez
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keith49vj3
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#19

12-28-2014, 06:16 PM
Thanks Ron,
I'll order a new tube but it sounds like the7G7 tube probably isn't what's causing the loud ticking sound.
Keith
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