Why no love for this GE roundie ?

[Electronic M]

Originally Posted by tvcollector

I'm reading the Sams under misc Adjustment - Horz Sweep circuits.. It's telling me to connect a 0-500ma meter to in series with cathode lead of Horz Output Tube and .47 mfd cap across the meter.. Then it says to connect a 0-1500 meter in series with the cathode lead of HV regulator tube.. Then tells me to adjust some controls and one being the horz osc control and some measurements.. At this point I'm already thrown completely off.. It does say to adjust the horz adjustment on the TV set control to the middle.. So that I'm aware of.. When I looked under the set where the 6j56 horz output tube is, i saw metal jumpers under the tube socket that connects to different pins.. looks like that would need to be unsoldered to connect amp meter in series.

I could either let Dave take over from here and restore the set, or attempt myself.. I've gotten this far.. Looking at the old coil, the slug is adjusted way down into the coil verses this new one, so I could either adjust the slug on the new coil to around where the old one is, then turn the set on, and slightly adjust right/left until I lock horz in.. Or I could be walked through on where to connect the meter.. Which I'm not expecting anyone on here too..

The exact procedure may help me to dissect it into it's constituent parts, but I'll try to give you a general breakdown. Usually sam's rolls adjustments of the various sections in and effected by the horizontal into a single procedure when they could be done one at a time. Usually it starts by adjusting the oscillator (which is what you most need to do), then it goes into horizontal linearity/efficiency adjustment* followed by HV adjustment*#.

*The .47 cap and meter thing is this part. While it is not ESSENTIAL that you do this part, you should because it checks the current through the HO Tube into the fly and minimizes it to prolong the life of those parts. What you need to do is trace the HO Tube base pin out from the schematic, and find the cathode lead (which should go to ground) break that ground (make sure you do NOT break heater ground too as it will mess up the adjustment) and insert the cap and meter (I prefer to use an analog meter[mine is from Rat Shack] with about a 250mA DC scale) then adjust the H linearity/efficiency coil slug for minimum current (usually between 185 and 210mA). On some sets there is a 250mA fuse in series with the ground you want to break if there is not one in your set you may want to add one to protect the flyback...If you do mount it above chassis where it is easy to check, change, and remove to re-do the linearity procedure/current check.

*#If you don't have an HV probe then don't try the HV section of the procedure....There may be ways of checking and adjusting the HV without a probe, but the sam's HV procedure should be considered invalid if you lack the proper measuring equipment for it.

To be honest with you I always do the first two pieces of the horizontal procedure (osc and lin, though not always at the same time or together), but have NEVER done the sam's HV proceedure....I usually just put a probe on the HV turn the brightness to min, adjust HV to speck turn the brightness up and watch that the HV don't slump significantly before hitting the ragged high end of watchable brightness...That basically does the same thing only with less metering, and prep work.

If you are still confused feel free to ask me, and include readable pictures/scans of the horizontal section and procedure so I can be more speciffic.

EDIT: BTW there are often two slugs in an H. osc. coil (you will see 2 sets of ferrite core lines next to the ocs coil on the schematic if that is the case), and it can be necessary to use the diddle stick in your set that is narrower up the shaft from the hex part...That stick should be able to turn the top slug, but also to drop through it, turning the bottom slug independently when dropped through the top slug.