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  #31  
Old 04-15-2015, 07:13 AM
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yes the 361084 is the magnavox number and i have a fly 305 new in box for the maggie combo i have. if you need the fly why dont you take this combo i have here with the fly for 250.00, it has been for sale but i need the fly with the set but if i didnt have this combo then i wouldnt need the fly. need to downsize here alittle, not much room and besides your chassis is and looks exactly the same as mine, a spare chassis helps and this combo works fine, even the flyback.
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  #32  
Old 04-15-2015, 11:17 AM
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Quote:
Originally Posted by timmy View Post
yes the 361084 is the magnavox number and i have a fly 305 new in box for the maggie combo i have. if you need the fly why dont you take this combo i have here with the fly for 250.00, it has been for sale but i need the fly with the set but if i didnt have this combo then i wouldnt need the fly. need to downsize here alittle, not much room and besides your chassis is and looks exactly the same as mine, a spare chassis helps and this combo works fine, even the flyback.
Last combo he had almost got parted for space reasons (but another member saved it), and earlier in this thread I seem to recall his mom telling him "this is not going in my house" about that little table/legged console...So I doubt he will take you up on this.

If the HV on your set is good, and the fly in it don't look too cooked then I don't see why you would need a spare flyback. Sure it is nice to have a spare fly, but if you dip the horizontal current, add a 125mA (or other appropriate value for the given design) HO tube cathode fuse, and maybe open the HV cage some (or add a fan) to increase air flow the fly should last for a very long time.
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  #33  
Old 04-15-2015, 01:17 PM
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Tom is right.. Thanks..

I did a little more poking around and I'm not sure if the flyback in mine is dead.. It sure doesn't hurt to have a spare.. I measured cathode current and it's suppose to be at 200ma, It doesn't stabilize and is way up past that, even turned the slug in the osc coil, gives me wacky readings between 220ma to well over 300ma, and meter just keeps climbing, flyback was getting warm while doing all this.. I tested the Horz osc tube and it's weak, looks like there has been caps replaced on the sweep board before...
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  #34  
Old 04-15-2015, 01:46 PM
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What is the HO tube grid voltage relative to specification? If it is not as negative as it should be by a decent margin then your H osc. is dead or not functioning correctly. I'd order a new osc. tube if the old one is weak. Sometimes a weak tube will work as an osc., but it is at high risk of sudden random failure and when the osc. fails if let run too long damage to the HO tube and or fly usually result.
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  #35  
Old 04-15-2015, 06:00 PM
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I'm getting -72 DC volts at pin 7.. Sams calls for -120.. Someone must have replaced or removed the Horz osc, one or two of the solder pads have been burnt off and jumpered from the horz osc..
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  #36  
Old 04-15-2015, 06:32 PM
Paul Knaack Paul Knaack is offline
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Good luck, I hope the fly is good. The tuner gears are in the mail.
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  #37  
Old 04-15-2015, 06:42 PM
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Thanks Paul..

I've just tested of the resistors on the sweep board.. There are alot of them that are way out of spec.. Not sure if it's because they are still in the circuit... Flyback area still has that burnt wood smell, smells like wood that was burnt and wet afterwords, sorta like a wet burnt smell I wanna say.. I wonder if that's a combination of the wax paper on the fly and the nicotine that was burnt..
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  #38  
Old 04-15-2015, 08:33 PM
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Quote:
Originally Posted by tvcollector View Post
I'm getting -72 DC volts at pin 7.. Sams calls for -120.. Someone must have replaced or removed the Horz osc, one or two of the solder pads have been burnt off and jumpered from the horz osc.. Sams and the printed boards are incorrect from each other...
The osc. signal is definitely not properly reaching the HO grid. Test and or replace all suspect parts in the osc, and all parts from it leading to the grid of the HO Tube.

A near 50% positive increase in the HO grid voltage is the main cause of the problem. The HO tube is going to conduct way too much current until it's grid drive signal is made right....I recommend removing the top lead and disconnecting the screen grid (not the control grid) lead from the socket of the H output tube. until you can get the grid voltage back in the ballpark.
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  #39  
Old 04-15-2015, 10:10 PM
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Are you still suspecting the horz osc coil is still the suspect? or should I test and replace all caps and resistors in between? I'm going to order up all the caps on that board and replace them anyways seeing how there's a problem, and there are a few resistors in between that are giving wacky results.. I'm still waiting for the tubes as well..
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  #40  
Old 04-15-2015, 10:49 PM
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a few things..

what are you using to check the voltages, a VTVM is best.

have you tried a known good osc tube 6FQ7

Note the grid circuit includes a voltage divider as part of the horz hold. Since the grid is too positive a good start would be to check the parts in that circuit,mainly the 22k resistor to ground from one side of the horz hold pot.

I would be scoping the cathode and check the free running freq (no signal) to see if its in the ball park.
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  #41  
Old 04-15-2015, 11:47 PM
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Using a regular ohm meter.. Klein tools to be exact..

I'm waiting for a few spares as for tubes.. I checked that 22k resistor and it's within spec..

I'm going to order up the caps and the resistors that are out of spec and just start replacing.. Only a couple of resistors that check way off, but those are probably the ones that give a proper readings out of circuit..
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  #42  
Old 04-16-2015, 07:27 AM
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interesting so the you lifted the 22k for testing? its in circuit as well.
did you use the sams to check the pin resistance readings?
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  #43  
Old 04-16-2015, 08:14 AM
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Be careful of the 6CG7/6FQ7 you use. The RCA side getter (clear top) types are controlled warmup time just for horizontal circuits. RCA made it to get drive to the HOT as fast as possible and to make sure the oscillator was stable and gave a locked in picture when the HV came up.
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  #44  
Old 04-16-2015, 11:31 AM
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That voltage you posted was the H output grid voltage right? Normally I use 'HO tube' to refer to the output and 'H osc.' to refer to the oscilator.

If the H out tube grid is not as negative as it should be by more than ~15% the osc. and the parts coupling it to the output tube are automatically suspect.

My approach would be to replace any resistors that are out of tolerance, change the caps, make sure the osc. coil ohms out similarly to the values in the sam's and that it don't look damaged, and perhaps most importantly get a strong osc tube in there.
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  #45  
Old 04-16-2015, 12:32 PM
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It's the grid off the 6FQ7 that I did the voltage check which is a tube that needs to be replaced.. I tested the 6JE6 horz output tube and it tests very strong... The horz osc coil also appears to look fine...
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Last edited by tvcollector; 04-16-2015 at 12:42 PM.
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