9th Apr 2010, 12:57 pm | #141 |
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Re: Tv62
Ok Jeffrey will do,
just found one other which is 12v 1.25A would it suit better or does it really not matter as you say. Last edited by oldticktock; 9th Apr 2010 at 1:03 pm. |
9th Apr 2010, 1:45 pm | #142 |
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Re: Tv62
Really doesn't matter. Whatever's more convenient. Just try to measure the voltage on load to check it isn't above 14V DC.
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9th Apr 2010, 2:03 pm | #143 |
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Re: Tv62
I decided to put the new electrolytics in place to see how they would fit and how I would arrange them. Lucky for me the 100+100uF slotted into the old can position nicely. The 220uf was clipped to chassis just behind, whilst it was all there I thought might as well solder it in place.
So now the fun begins, just going to reinstall back in the case and fire up I will report back with results. Chris |
9th Apr 2010, 4:01 pm | #144 |
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Re: Tv62
Ok Set switched on The big bad hum is gone.
Now with volume on max I just get the usual volume hum. nothing on screen no life from EY86 Chris |
9th Apr 2010, 4:12 pm | #145 |
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Re: Tv62
Any buzz from the frame timebase? Any whistle from the line timebase? Adjust the frame and line holds up and down to make them more audible. If something's audible that's a very good start.
Any visible distress? Especially in the LOP valve. If there is, need to switch off and track it down. If no audible evidence of timebases, since you've had the set apart it's worth poking around with a meter to see that HT is getting to where it ought. At this point, if HT is present, since I'm really a design engineer rather than a TV service guy I tend to dig out the 'scope and see what I can find. John W, Trevor and others with far more experience will have simpler methods. The worry now is that you could be dealing with extra problems, caused by dismantling and reassembly. |
9th Apr 2010, 4:21 pm | #146 |
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Re: Tv62
I now have a whistle, variac was only set at 200 now at 240
A pale purple glow in the EY86 and I mean very pale, it started brighter and I saw a little spark going round then it stopped now the glow has settled and is only best seen with the lights off. Crt now has a pale glow at base where connector is assume the heater. When I adjust the line hold the whistle increases in intensity when rotated clockwise and decreases when turned anti clockwise. all valves nicely glowing Chris Last edited by oldticktock; 9th Apr 2010 at 4:35 pm. |
9th Apr 2010, 4:49 pm | #147 |
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Re: Tv62
This is sounding better. The line whistle should actually change pitch as you adjust the line hold. A change in loudness is incidental. Using a well insulated screwdriver you should be able to draw sparks from the LOP anode and bigger sparks from the EY86 anode. DO NOT EARTH THE SCREWDRIVER. You should also be able to draw thin yellowish sparks from the EHT, either at the CRT or EY86 cathode.
EHT present? Good. If not, we need to sort that before anything else. Can you see anything on the screen as you adjust the brightness control? No? Time for further tests. Measure the voltages on the CRT base. They should be on either the Bush or trader bumph. The cathode should have video on it, DC level probably a few 10s of volts. The grid voltage shoudl vary with the brightness control. The first anode should have a few 100 volts on it. |
9th Apr 2010, 4:58 pm | #148 | |
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Re: Tv62
Quote:
EY86 anode i touched the lead wire where it hits the solder point, got a little blue spark. nothing on screen when brightness adjusted Is it alright to measure with my bench meter all pins on the CRT base? and what is the pin order? Ok looking at the connector working clockwise from the connector notch pin1 63v pin2 12.5v pin3 154v pin4 12.6v pin5 2.8v pin6 154v pin7 4.1v pin8 98v pin9 98v pin10 121v pin11 97v pin12 4.7v Last edited by oldticktock; 9th Apr 2010 at 5:21 pm. |
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9th Apr 2010, 5:27 pm | #149 |
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Re: Tv62
Chris, I'd play on the safe side and use a stabilised PSU. I have seen warnings on the Aurora site that the device could be damaged if the input is too high and some of these cheap PSUs can go way up. Personally I use a switched 1A output device on 9V.
Dave |
9th Apr 2010, 5:38 pm | #150 |
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Re: Tv62
Most of the CRT pins are irrelevant here. It's just like an octal base but with 12 pins so pin 1 next to the locator notch, clockwise round to pin 12.
Cathode: pin 11, 72V Grid: pin 2, 0-200ish, varies with brightness control 1st anode: pin 10, 380V Heater 1&12, should be 6.3VAC across these Pin 3: No pin. Used as connection point only. pin 6: Says A2+A4 but seems to be unconnected on Bush circuit. i'm a bit confused here. EDIT: It's the focus anode. COnnected to pin 1, 3 or 10 for 0V, about 200V or about 380V. Not critical at this stage. You won't see anything on screen unless the grid voltage is fairly close to the cathode. You can short them together with a clip lead to force the CRT to conduct. Make sure the brightness control is about midway first. PS: David I agree a stabilised supply is the way to go but provided it's under 16V on load you won't hurt the Aurora. For continuous running then 7 to 12V on load is ideal. The off load voltage of an unregulated supply may be quite a bit higher than the on load voltage. If you're nervous use a 47R 5W resistor as a dummy load to check the on load voltage. I use an anonymous 9V 1A wall wart which happened to be in my box. Don't even know if it's stabilised but it's fine. Last edited by ppppenguin; 9th Apr 2010 at 5:52 pm. |
9th Apr 2010, 5:56 pm | #151 |
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Re: Tv62
Couple more things. Is this bent gun tube? Bush bumph says no ion trap but Mullard data says it needs one. If the gun structure is obviously wonky looking then there should be an ion trap magnet which adds another complication.
Also sounds like the EHT is a bit weedy. Should be a good zap from the EY86 anode. Then a rather weak looking spark from the DC at the EHT connector or EY86 cathode. |
9th Apr 2010, 6:05 pm | #152 |
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Re: Tv62
Looks straight to me unless we are talking a subtle bend, I cannot see one.
Have a look at pic Shall I change the EY86? I'm new to TV's but i was expecting a much more vigorous glow from the EY86 Last edited by oldticktock; 9th Apr 2010 at 6:22 pm. |
9th Apr 2010, 6:08 pm | #153 | |
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Re: Tv62
Quote:
If you can get hold of a BY8424, you might be able to use that as a temporary substitute.
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9th Apr 2010, 6:11 pm | #154 |
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Re: Tv62
I have many spare EY86's/87's
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9th Apr 2010, 6:47 pm | #155 |
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Re: Tv62
Ok changed the EY86 and now I have I believe what you TV guys call a raster, its off-set and the width pot does not bring it right across. I'm wondering if I need to adjust that picture centering device but I guess I've got more going on with it being a single squashed line.
John W I believe the screen is talking to me but I don't yet speak its language The raster has shrunk a bit Chris Last edited by oldticktock; 9th Apr 2010 at 7:01 pm. |
9th Apr 2010, 7:00 pm | #156 |
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Re: Tv62
Great! You haven't got a raster yet because the frame timebase isn't dong its job yet. Keep the brightness down so you don't burn a line across the CRT.
Check the voltages around V2b and V3, the frame timebase valves. Don't worry about fine adjustments of width etc until you've got a picture on the screen. Doesn't matter if it's distorted and offset, just get a picture of some kind. |
9th Apr 2010, 7:02 pm | #157 |
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Re: Tv62
see I told you I don't know what i'm talking about
I have kept the brightness down the camera makes it look high. Ok i'm confused v2b is that the ecc82? on the main deck? Last edited by oldticktock; 9th Apr 2010 at 7:09 pm. |
9th Apr 2010, 7:12 pm | #158 |
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Re: Tv62
Hi Chris, your TV62 appears to have frame collapse so you need to look into the frame oscillator/output stages. The set also appears to have an Ion Trap magnet fitted, it is the clip located around the crt neck close to the base and it carries a small magnet.
Be careful about adjusting this as miss adjustment can cause you to lose the picture, panic and wonder what the hell is wrong. I have known engineers to spend hours trying to find a fault only to discover the Ion trap magnet was out of adjustment. Best wait until you have a full screen raster at least! Les
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9th Apr 2010, 7:25 pm | #159 |
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Re: Tv62
OK checked ecc82 voltages.
Bench meter to read ac/dc pin1 98 pin2 2.6 pin3 5.7 pin 4&5 strapped together (heaters) this cannot be right 79v pin6 110 pin7 cannot get a stable reading meter goes hay wire pin8 2.5 pin9 84 Sean Williams had a similar fault on his and it was the PCL83 frame oscillator although he did not have whistle which i do. He replaced the pcl83 and it worked Last edited by oldticktock; 9th Apr 2010 at 7:31 pm. |
9th Apr 2010, 7:34 pm | #160 |
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Re: Tv62
I think it's a centring magnet. OTT reckons it's a straight gun CRT.
BTW, forget about measuring heater voltages at this stage. You know they're OK. (Pins 4, 5, 9 on the ECC82, 4 and 5 on most B9A valves. PS: Set the meter to read DC. You'll confuse us all if you try to read AC. If you have an analogue meter then better still, it won't be confused by pulse signals. |