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Old 01-04-2018, 10:53 AM
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DavGoodlin DavGoodlin is offline
Motorola Minion
 
Join Date: Aug 2011
Location: near Strasburg PA
Posts: 3,400
Sencore SS105 - sweep troubleshooter question

Has anyone used one of these before? A very portable Horiz and vert sweep signal substitution like part of a B&K analyst. It sounds ridiculously simple to use from the SS105's manual, "just touch it to suspected components until sweep appears" probably because it makes a 100-200 v p-p v-drive sawtooth.

I have a 1958 Sylvania-made RCA-branded metal 17" portable that lost vertical sweep. The vertical osc-out tube is a 10DE7 in a standard multi-vibrator circuit. Osc plate voltage is 2 volts, should be 120vdc. So osc section must be conducting because the whole stage has stopped oscillating. I need to clear the output transformer and yoke as well as try a tube before looking for more component trouble.

Height and boost dropping resistors are good. Boost is 400v because horizontal sweep is working.

Background - I recapped this 100% a year ago and I was using it daily until spring, then I moved it to the shop for a long-hours test before I call it done. The burn-in must have been too long, and it lost vert sweep.
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