12th Nov 2015, 11:01 pm | #81 |
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Re: Philips B3G63A
TV aerials!
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12th Nov 2015, 11:27 pm | #82 |
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Re: Philips B3G63A
O.k. Andrew - you are correct of course and aluminium foil was first introduced back in the early 20th century.
But what is the purpose of the metallised sheet - it has an earth tag screwed to it? What is it actually made from? |
13th Nov 2015, 12:04 am | #83 |
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Re: Philips B3G63A
Hi Donald,
The fact that, despite the rustiest of chassis that follow you home, that foil is never rusty lends weight to it being aluminium. It's also non-magnetic. Unless someone knows better (quite likely on here!), in this instance on our Philips sets I think it really is as simple as aluminium foil glued to a backing paper. I can imagine that light brown gum stuff with the red rubber nozzle we had as kids to stick stamps in albums would be perfect as glue for this. It's used as RF screening in your radios case I would believe. Sometimes in other sets you will see it around the top and sides of a cabinet acting as a plate aerial with a lead connecting from it which can be fitted into an aerial socket. Usually it's OK for local reception. On one of my sets the foil, in that instance used a plate aerial, is quite thick with no paper backing. Another uses a sheet of copper under the chassis for RF screening. Regards _ Andrew
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13th Nov 2015, 12:10 am | #84 |
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Re: Philips B3G63A
The metallised sheet forms part of the internal FM earial. I suspect that on the AM bands it acts as screening from external electrical noise influence (lightswitch 'clicks', motors etc)
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13th Nov 2015, 1:09 am | #85 |
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Re: Philips B3G63A
It may not look quite the same, but cooking foil backed with self adhesive A4 label stock should do the job nicely. Stick it to the cabinet with spray adhesive.
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13th Nov 2015, 12:53 pm | #86 | |
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Re: Philips B3G63A
Quote:
You fired up so many childhood memories for me - I think I can still smell that glue!!! I'll try somewhere like Hobbycraft who should still sell it or something similar? http://www.hobbycraft.co.uk/craft-es...st-craft-glues Need to ask them what sticks paper to Bakelite? Is it advisable to remove all the existing paper and foil from the cabinet? Anyone got advice on my primer and paint question? |
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17th Nov 2015, 7:44 pm | #87 |
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Re: Philips B3G63A
Hi Donald,
I keep an aerosol can of carpet fitter's adhesive in the workshop. It sticks just about anything to anything, is quick drying, and being an aerosol is easy to apply evenly to a job like yours. And its a really tough bond, too. Tony |
17th Nov 2015, 9:35 pm | #88 |
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Re: Philips B3G63A
Spraymount or photo mount adhesive.
back in the days when jessops were in every town i used that for sticking flimsy photo prints to backing card. try an art supplier? A. |
17th Feb 2016, 2:38 pm | #89 |
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Re: Philips B3G63A
Hi guys - can't believe the amount of time that has passed since my previous post way back in November 2015 - doesn't time fly at our age??
Anyway, back on track with my Philips B3G63A project after finally managing to replace the snapped FM dial cord - what a job that was! This was only possible because of the advice, guidance and encouragement from boxdoctor (thanks Tony) who was very patient in answering quite a number of beginner level questions e.g. what does "gang at minimum" mean? Purchase of the special hook for the dial cord proved invaluable. So next step is to replace the power cord (discussed previously) and also the speaker cable that was a a bit worse for wear - cracked insulation etc. This shroud be enough to test that the radio is still working - all safety protocols will be followed with the bare chassis out the cabinet - don't worry, no family members, pets or anyone else will be present when I switch it on! I've built a lamp limiter for this purpose. The cracks and holes in the Bakelite cabinet have been filled and sanded smooth - final rub was with 1800 wet and dry so an excellent finish for the primer and paint. I'm still considering Halfords Grey Primer and Halfords Vauxhall Brazil Brown?? Where can I buy some Lada Cream (or similar) touch up paint for those areas on the front of the cabinet that need some attention? And lastly (for now) a few drops of trombone oil really helped free up the sticky control spindles - thanks again boxdoctor for that piece of advice. |
17th Feb 2016, 3:22 pm | #90 |
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Re: Philips B3G63A
Hello again Donald,
Pleased to see that you have managed to do the awkward dial drive! I ended up replacing all the cords on mine, eventually, as they started failing after a little regular use. I noticed some evidence of the FM discriminator being a little way off tune, and after some adjustment, as luck would have it, the core is now seized in the coil, (incorrectly tuned, and with the slot damaged) so I have made myself another irritating and fiddly job to do. It's on the roundtuit shelf for now. Moral: Dont tweak unless you really have to. Still need a back cover for mine, though. Glad the advice was useful, and good luck with the cabinet..Cheers, Tony. |
17th Feb 2016, 4:20 pm | #91 |
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Re: Philips B3G63A
Hi Tony and good to hear from you.
Of course I have to ask what is the FM discriminator and where is it on the chassis?? I note that you still need a back cover for yours - as mine is off currently I could trace the outline and cutouts onto a piece of card which would then enable you to make a replica in hardboard, MDF or something similar if you have a coping saw or fret saw?? A photograph of the back cover would also help you to see from the text what each slot and hole is for - just a thought? |
17th Feb 2016, 5:53 pm | #92 |
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Re: Philips B3G63A
It's that part of the circuit associated with the double-diode section of the EABC80. Edward
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18th Feb 2016, 10:04 am | #93 |
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Re: Philips B3G63A
Hi Donald,
Not to worry about the back cover, as I have enough of the original one to do a reconstruction when time permits. My wood-working facilities are somewhat limited though. Its a 'roundtuit' job just now, but it will get done in time. As Edward says, the F.M. discriminator coil (L23) is in one of the I.F. cans, which means taking the can out and sorting it out after dismantling. Just annoys me that I caused the problem!! Do try an EF183 or EF184 in place of V1 and/or V2 if you have one or two. It brings the F.M. sensitivity up quite a lot. Cheers, Tony. |
18th Feb 2016, 10:48 am | #94 |
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Re: Philips B3G63A
Thanks Edward and Tony - need to focus on reassembling the radio which is in about 100 bits if you include all the screws, bolts and wires. Finishing off the cabinet is also a priority but still waiting on feedback regarding my paint questions?
Once I have a working radio I'll consider AM and FM alignment but that really is the Advanced class for me as I don't have any of the Test Equipment (apart from a digital voltmeter) detailed in Trader Service Sheet 1374. Tony, I loved your comment "Do try an EF183 or EF184 in place of V1 and/or V2 if you have one or two." If I need to replace V1 and/or V2 (EF80s) with an EF183 or EF184 where is a good source to purchase these? Last edited by DonaldStott; 18th Feb 2016 at 10:49 am. Reason: Wrong word |
18th Feb 2016, 1:29 pm | #95 |
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Re: Philips B3G63A
These valves can be bought via ebay or from Kenzen, Chelmer or Billington - just google them. However, if you are not worried about the increased sensitivity, replacement EF80s are dirt cheap. Edward
PS: THINKS - This topic would make an interesting new thread. "Plug-In Upgrade Valves"... |
19th Feb 2016, 10:06 am | #96 |
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Re: Philips B3G63A
Hi Donald
If you know any ex- T.V. service engineers, they may have one or two around. Probably for free, or the price of a pint. They were very common in valve TV sets in the '60s. Another good source of 'bits' is amateur radio rallies. See here :http://www.g4rga.org.uk/index.html A wonderful source of cheap parts (and other interesting stuff!) Edward - Thats an interesting idea for a new thread! Cheers Tony. |
19th Feb 2016, 3:37 pm | #97 |
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Re: Philips B3G63A
Although I have very limited experience in this field, I take the view that the valves in my Radio are now 60 years old so none of them will be operating at optimum performance?
They are electrical components so they will wear out with age - I don't have a list of all the things that can go wrong with valves, what % performance you need or can even measure? Should all valves in radios of this age simply be replaced as a matter of course given how cheaply replacements can be picked up - hope this sin't too controversial? |
19th Feb 2016, 5:11 pm | #98 |
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Re: Philips B3G63A
Hi Donald,
The valves in my current project are at least thirty years old and could quite possibly be original (sixty years old). The radio sounds great. The tuning indicator had failed, but these can actually wear out. I watched a video recently featuring the famous Gerry Wells. Gerry started fixing radios in the 1940s. In the video Gerry recalled that back in the day a lot of radio repair outfits would spend a significant amount of time diagnosing faults eventually traced to failure of components that were very cheap to replace. So, they would falsely report a valve as faulty to get some extra dosh. Apparently this was such common practice that the consumer eventually believed valves to be unreliable. Maybe some "experienced" engineers could confirm or deny |
19th Feb 2016, 5:36 pm | #99 |
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Re: Philips B3G63A
I speialise in the repair of portable record players from the 1950/60s so you can work out their average age. In the last 20 years I have only ever needed to replace 2 valves from working on scores of players. Edward.
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19th Feb 2016, 5:47 pm | #100 |
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Re: Philips B3G63A
Valves do not deteriorate with age but with use, and then very slowly. The majority of valve radios working today have all or most of their original valves, and there is absolutely no need to replace any in the absence of a fault. The most likely valves to fail are the rectifier and output valve as these work hard, but even these often turn out to be fine.
As mentioned in #98, the idea that valves need frequent replacement may come from a bit of sharp practice by less than honest service engineers in the 50s. They would be called out to fix a fault and would cure it by changing a capacitor or something equally cheap and simple. To increase the bill they would change a valve as well, and take a cut of the price. |