15th Sep 2011, 3:24 pm | #141 |
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Re: Restorers dream part 2 the chassis.
Hi Colin.
We are all human you know! That is what I call the learning curve, something we all do to the day we die! Go on plug in the aurora!
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15th Sep 2011, 3:25 pm | #142 |
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Re: Restorers dream part 2 the chassis.
All stand up and sing 'Rule Britannia'. It had to be something daft Colin. Don't blame yourself honest. We all make these types of mistakes and will continue to do so.
WELL DONE! More of a lighthouse than first light. Good tube as expected and even a reasonable raster. Loads more to do [cap in tuner, video output anode load resistor. More of this little beast later] and plenty of solutions but don't want to bog you down with component lists at this time. I thought I was going to have to get the huskies and sledge out for an expedition up north around Christmas time but it appears this may no longer be required. The best of luck with the finale. Regards, John. |
15th Sep 2011, 3:39 pm | #143 |
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Re: Restorers dream part 2 the chassis.
Having come in on this thread toward the end, I am, once again struck by the thought that Col is truly an inspiration to us all. He never gives up - and on his way to ultimate success he entertains and guides everyone who reads his progress reports. Well done, Col. You never cease to amaze me.
Tony |
15th Sep 2011, 3:43 pm | #144 |
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Re: Restorers dream part 2 the chassis.
Hello Colin,
Rubber glove on. No voltages present here but will take away the fear factor and make a simple job a lot easier. I have named the various adjustments for set up. The scan coil lever will revolve the coils around the neck of the tube to square the picture within the tube area. The picture position shuffle plate can be unlocked with the locking screw. It will then be found that by sliding it from side to side and pulling the lever up and pushing it down you will be able to centre the picture within the screen area. The ion trap is adjusted for maximum brightness at all times. Use the adjustments mentioned for centering and squaring up the picture, never the ion trap. The large rotary knob on the rear of the assembly is for FOCUS adjustment. Hope this helps. John. |
15th Sep 2011, 3:44 pm | #145 |
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Re: Restorers dream part 2 the chassis.
Well done Col, the info I gave you was for the T200 series sets and may well not be the same for the T300 series. If you now have control of the brightness it means there is a resistor from the cathode of the tube to earth not used in the earlier sets and I gave you wrong advice. The important thing is you now have the set working, well almost. Can't wait to see the pictures.
Victor. |
15th Sep 2011, 4:18 pm | #146 | |
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Re: Restorers dream part 2 the chassis.
To quote Charlie Duke, the capcom when Apollo 11 landed, rather out of context:
Quote:
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15th Sep 2011, 4:43 pm | #147 |
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Re: Restorers dream part 2 the chassis.
Hello Col quite simply WELL DONE, I have been joining the thread at every opportunity to see what was happening, I hope that you were not knocked off your chair with the volume of cheering and hand clapping, you are an inspiration to me too keep going no matter what.
Cheers and all the best. Geoff. |
15th Sep 2011, 5:15 pm | #148 |
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Re: Restorers dream part 2 the chassis.
Col. Have you tried shorting the tubes cathode to grid? This will switch it hard on and will narrow down the fault(s) you are looking for.
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15th Sep 2011, 6:03 pm | #149 |
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Re: Restorers dream part 2 the chassis.
Sorry Col. Just catching up and I seem to be behind with the thread.
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15th Sep 2011, 7:06 pm | #150 | |
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Re: Restorers dream part 2 the chassis.
Quote:
Class. I love it.
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15th Sep 2011, 7:31 pm | #151 |
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Re: Restorers dream part 2 the chassis.
WELL DONE from me two. First light is a wonderful thing but your first first light is such a good feeling. cant wait for more progress. your work is inspiring me to get on with a basket case restoration that has stalled.
Jay
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15th Sep 2011, 8:10 pm | #152 |
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Re: Restorers dream part 2 the chassis.
Hi,
What a day I’ve had. A gorgeous day weather wise; a lovely three mile walk in warm sunshine and now success with “first light” days seldom come better than this. Yes Dom & Keith; next job is to connect the Aurora and get the test card on the screen; I can’t wait and already I’ve had the Aurora fired up and flashing powered by a 9V battery but drat it; I thought I had some coaxial cable and spent an hour searching for it without success; I don’t like doing bodge jobs so will get hold of some if Mike hasn’t any to bring along when he visits tomorrow. Thanks Trevor and John; during my lifetime I’ve had many steep learning curves but this one was akin to jumping off a cliff and learning to fly; not so much a curve more a vertical line and ballistic at that. Huskies were not needed after all John but it was definitely cold in the workshop very early this morning; I almost dashed out to fit the winter tyres!! Thank you so much Tony I am deeply moved by your most kind sentiments and continued encouragement both on forum and as a friend via email; such compliments from a renowned expert is praise indeed; thank you. John you really are a scream at times but I’ve cried enough for one day; I’ve never found my way around a chassis as quickly as I’ve done with this one and for other novices I think the areas to be wary of regarding EHT are the upper LOPT area including the two valve top caps; keep away especially with a meter and also the CRT coating which remains live even with power turned off; I did as Dom suggested and installed a good thick lead giving a direct short between the metal band around the screen and chassis; the metal band on this CRT has a set of metal fingers pressing against the coating. Not EHT but I took a lot of care to ensure mains neutral was by-passed through the on/off switch by adding a short between both tags connected directly to chassis as Joe kindly advised. I’m certainly not over confident John but the rubber glove isn’t needed or at least I hope it isn’t. I also enjoyed following your advice on how to draw lightning from the U25 John and was most impressed by this; it even looks better done in very poor light. No harm done whatsoever Victor and thanks for posting. Thanks Jeffrey; I think I was more amazed than anyone when I saw first light after spending so much time; as I’ve stated many times I’m colour blind and Trevor states that there might have only been a slight change in the display so I was worried about totally missing it; this drove me mad as the screen kept changing with the outside conditions throwing me way off scent; as it turned out though when first light did appear I needed sunglasses. We can all take a deep breath now. Thanks Geoff; I’m pleased this story has been so well received; what a great bunch of guys you all are; all through this chassis restoration all I’ve ever received is help and understanding; it would have been easy for me to feel well out of it but everything has been explained in a straightforward simple manner that even I could understand; at no point have I been put down or felt intimidated; yes I’ve caused the odd laugh but even this was kind hearted and I could join in; if I can get such a wreck working in such short time due to your expert help and guidance then any novice has nothing to fear from doing similar restorations; it’s been a wonderful experience for me and to be honest I feel rather sad that I got first light so quickly as it was very interesting for me and I love a challenge. No problem Dave and thanks for posting as the advice is worth repeating. I was just about to post this when I saw your message Jay; many thanks; yes it was a delightful experience in seeing my very first light and good luck with your basket case; these to me are the best to play with. Had it not been for a buried mains cap which took a great deal of finding and my mistake in removing the EHT lead again wasting a lot of time this chassis would have seen first light much sooner; I’m amazed I’ve seen first light at all. Thank you all once again for your patience and for reading my rambles. Kind regards, Col. |
15th Sep 2011, 8:16 pm | #153 |
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Re: Restorers dream part 2 the chassis.
Excellent result so far Col. Like many, I've been quietly watching this thread with great interest from the back. Easy mistake re the metrolsil!
He who makes no mistakes has never made anything at all! Greg
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15th Sep 2011, 9:32 pm | #154 |
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Re: Restorers dream part 2 the chassis.
Hi Col I suspect that you already know this but I was caught out and nearly had a fright thinking gawd now what has happened.The Aurora cuts out after an hour if only displaying the built in test card, simply cut the power supply to it for a few seconds and away you go again.
Cheers. Geoff. |
15th Sep 2011, 9:59 pm | #155 |
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Re: Restorers dream part 2 the chassis.
On most versions of the Aurora this auto-switch off "feature" can be disabled by switch setting. If you let me know the version number (on the label) I should be able to tell you. Should also be in the excellent manual that Darryl provides for download from his website.
I never quite managed to persuade Darryl to scrap this "feature" which ahs caused several people to wonder whether their Aurora was broken. |
15th Sep 2011, 10:37 pm | #156 |
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Re: Restorers dream part 2 the chassis.
I have been following this thread with great interest and all I can say Col is well done! you have come to the conclusion yourself which in itself is excellent work and as you claim you are too a novice at this game I have to tip my hat to you
Now go and celebrate with a or two!! Cheers
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15th Sep 2011, 11:40 pm | #157 |
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Re: Restorers dream part 2 the chassis.
One word....
RESPECT!
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16th Sep 2011, 12:24 am | #158 |
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Re: Restorers dream part 2 the chassis.
Ha, Ha, Col,
Good to see this looks to have put you in excellent spirits. Re, the Aurora, coupling it to the set with a random piece of wire may be a bodge but that little box of tricks puts out such a strong signal that a 1" piece of wire hanging out of the RF port and 1' hanging out of the telly tends to work as a broadcast system so don't go waiting until you find some coax. If not go an have a dig behind the telly while bron isn't looking I'm sure you can borrow a foot's worth from the living room set! Keep up the good work - I'm off in the morning but will be following! Dom |
16th Sep 2011, 7:09 am | #159 |
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Re: Restorers dream part 2 the chassis.
A couple of feet of any old wire will do to connect the Aurora to the TV for now. Assuming the Channel 1 biscuit is fitted in the tuner that's the best one to use for this sort of bodgery. Otherwise any other Band I channel.
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16th Sep 2011, 8:46 am | #160 |
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Re: Restorers dream part 2 the chassis.
Hello Colin,
Now you are almost ready to proceed with work on the frame timebase and signal circuits it might be as well to warn you that some capacitors in Ekco receivers appear to be into cross dressing. They look exactly like resistors but under their coloured frocks they are in fact low value capacitors. They are dark brown in colour with coloured bands that read exactly as the resistor code. i.e Brown Black Red = 1000pf. They generally tend to go O/C after all these years but sometimes develop a very high resistance leak, enough to upset frame linearity. The big fat diode pictured is the frame interlace filter [D3]. Again it goes O/C giving very poor frame lock. These components were made by a company owned by Ekco named EGEN situated just down the road from their factory at Canvey Island Essex. Ekco timebases should be rock solid. It can be replaced by any small diode such as the 1N4001. Another very puzzling fault, poor contrast, odd contrast operation, contrast overload and brightness variations is often due to the video amplifiers anode load resistor [12k] going high resistance typically around 20K. Worth a check. Similar symptoms to the above are also caused by the .1uf wax capacitor INSIDE the tuner. Easy to replace once you know it's there. It decouples the AGC line and goes very leaky. The tuner bottom cover [if it's still there..] will need to be unclipped and the R.F. coil biscuits removed to gain access. I can post a pictorial explanation of this if you need it. Can't think of anything else that will slip you up at the moment. If the AGC decoupling capacitors are leaky you may find it difficult to adjust the contrast. The AURORA output is clean and strong and the uncontrolled signal stages may overload and give a negative picture. Cheers, John. |