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#16
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Had a sit-down with the scanner today, worked through the radio and TV schematic info and service docs.
Scans can be found here for those interested, they're at 600DPI so they shouldn't look terrible. http://vintagepc.co.nr/site/fleetwoodtv/service/ Radio_006 is for the radio chassis, TV_SCHEMA is a stitched full schematic of the TV chassis (it spanned two pages) I know there's some projects out there that collect these sorts of info on sets, which one would be appropriate to submit this? |
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#17
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Okay, here's where I'm going to need some info from the more experienced folks.
I had a look at the TV chassis and schematic to double check that it matches before I go ordering parts and find out there's a major discrepancy ![]() There's one thing I found that is off - in the schematic, V8 is marked as a 6W6 and has the first audio stage coming in on pin 5. However, in the chassis, this is wired to pin 6 of the socket, and I found not a 6W6, but a 6V6 instead. A quick search says they're pin-compatible but not exactly interchangeable, any thoughts on this? Last edited by VintagePC; 05-20-2013 at 09:42 AM. |
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#18
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Nobody?
Would this thread be better off in the "rectangular tube" section vs the "early B&W" section? Not sure how much crossover there is from one to the other forum
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#19
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Quote:
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#20
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6W6's seem to attract less audiophools than 6V6's do. This helps you buy 'em for less on ePay...
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| Audiokarma |
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#21
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Thanks for the info.
Further update: I've gently removed the picture tube so it's easier to manipulate the chassis for the first round of recaps and cleaning. The entire yoke assembly slid right off. Getter looks good so the tube hasn't gone to air, but I don't have a multimeter right now (need to locate it first) so I can do some basic all-around tests on the important bits before I buy $50 worth of caps to recap the set. (of which about $30 or so is just the electrolytics) |
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#22
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I can't get your schematic links to come up for a look-see, but they would be correct in showing signal coming in on pin 5 (control grid, G1). You indicate the signal is actually going to pin 6, which is a blank pin. Is there evidence of somebody messing with it and miswiring it?
Last edited by old_coot88; 05-25-2013 at 05:07 PM. Reason: Major brain fart. Was confusing 6W6 with 6K6 . Doh. |
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#23
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here's the direct link to the schematic, does it work for you?
http://vintagepc.site50.net/site/fle.../TV_SCHEMA.png I'm refraining from embedding them because they're quite high-res files. I took a closer look at the socket and I saw it is indeed wired to pin 5 with a resistor. They used pin 6 as a tiedown point and the resistor was hidden in the mess of stuff coming off it. |
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#24
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The 6V6 heater current is 450 ma, and the 6W6 draws 1.2 amps. That might be a consideration. In an audio output stage, they probably will work in place of each other, as long as the 6W6 heater can be supported without overloading the transformer winding. In a vertical output circuit the sub might not work all the time.
__________________
stromberg6 |
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#25
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Ah, so in this case it'll help the set transformer run cooler as it's specced for a 6W6. Good to know.
![]() I have some investigating to do, as I noticed there is a loose piece of wire (both ends detached) floating around inside the HV cage. I don't immediately see where it is supposed to be attached, and I'm not sure whether that's a good or a bad sign... |
| Audiokarma |
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#26
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I moved this thread to the Rectangular Tube Forum as you suggested.
It would make it easier to follow what you are doing if you uploaded the pictures directly here instead of linking them. There is a size limit for uploaded pictures so you would have to shrink them down but that's pretty easy to do. 600 pixels wide is usually large enough to be easily legible. I think something like 150k is the maximum file size, not sure about the dimensions, there may be no limit as long as the file size is OK. If something needs to be really high res you could link those images, schematics for instance. You could also host them on your own Site and use the [IMG] [/IMG]tags to embed them here, however if there's a lot of embedded images and they are all huge it will take a long time to load the page. |
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#27
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Thanks for the move, this forum is probably better suited to it.
I've gone and updated all but one of the posts to now embed smaller versions of the images - the last remaining one I'll have to pull the images from dropbox first as the USB on my phone went south. Further update on the stray piece of wire I found - it doesn't seem to be missing from anything; all the required connections to the various components inside the HV cage are correct. When I removed the CRT, there was a cushion between the chassis and CRT support which I suspect was once rubber, but is now rock-hard. Has anyone sourced a replacement for such things before? Looks to be about the size of a standard toilet gasket, might be able to pick up a rubber or neoprene one at the hardware store that would work in a pinch.
Last edited by VintagePC; 05-25-2013 at 06:40 PM. |
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#28
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Had a poke around with a DMM today, looks promising. CRT has good filament and no measurable shorts to any of the elements, and power transformer/flyback seem to ohm out okay as far as I can tell without unsoldering them.
One question - is it normal for a line choke and VBO transformer to have high resistances (>200 ohms)? |
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#29
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Hello again VintagePC. You surely remember me, as I do remember your earlier
Fleetwood project. I'm glad you found that nice Canadian built TV, with a radio and phono to boot! I will be away for a few days, but be sure to contact me with your tube needs, I will be more than happy to help again. Bye for now. P.S. : note that this TV uses a stacked power supply, meaning that the cathode of the audio output tube is used as a supply point for lower voltage stages. It is quite important that the output stage be correctly operating in order for all the plate supplies to be at the correct voltage. Better have a good working tube of the correct type in that position. Regards. Last edited by electroking; 06-03-2013 at 10:59 AM. Reason: added note |
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#30
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Quote:
Interesting supply setup for the TV, and indeed something to keep in mind when working on it; more troubleshooting complexity when things go wrong! The radio side uses 6V6s for the output stage (and while specced for a 6W6, audio output is also a 6V6) so of three total, at least one is hopefully good ![]() Current project status is on hold as I'm going to be too busy for a few weeks, but after that I should be ready to order up some caps and get restoring. (There's about $50 worth in the radio and TV combined, $25 of which is the 12 or so electrolytic can sections by themselves. Now that I know the power transformer and flyback aren't open circuit or dead short, I am ready to take the plunge and do the order. There's some bodgework around the VBO transformer, which appears to have been replaced along with the vertical height control; I don't know whether the picture tube is original but it looks as though at some point the vertical failed. Fortunately no signs of burn-in or damage on the phosphors, so either the tube was replaced or it was caught before any damage occurred. I'll clean up the macgyvering of the transformer (the blue wires I incorrectly attributed to the yoke earlier) but leave the control in place for now unless there are problems. I haven't found any major problems during my initial inspections apart from a blown dial lamp and some mouse-nibbled capacitors, and all indications seem to be that it should be in working order when recapped. I'd originally thought to do some restuffing but that may be hard with the plastic molded caps, and some of the paper nibbled ones are too far gone (though I did save the ones from my 4068 and could use them instead). Last edited by VintagePC; 06-03-2013 at 11:38 AM. |
| Audiokarma |
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