11th Sep 2015, 12:17 pm | #61 |
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Re: Philips B3G63A
Thanks again to Tony, Paul and Nick - more stuff for me to ponder?
Main challenge is how to get in about R15 (56 kΩ) on V4 which is an EF85? I've got a very basic multimeter so I looked at the Fluke range - anything from £80 to £160 - any recommendations. I though the preferred option on this Forum was the AVO 8? Last edited by DonaldStott; 11th Sep 2015 at 12:17 pm. Reason: Typo |
11th Sep 2015, 12:36 pm | #62 |
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Re: Philips B3G63A
Hi, Donald,
One of the reasons that the Avo 8 is popular in this forum is that, back in the day, it was, perhaps, the premier field instrument for radio work. Consequently when the radio etc manufacturers (and some third parties) released their servicing information, they would state that the sample voltages at the various specified test points on the circuit diagram were taken, say, under no signal conditions with an Avo Mk 8 multimeter (or perhaps they'd just say a 20,000 OPV voltmeter). There's absolutely nothing to stop you using a modern digital multimeter (like the Fluke), but because the Fluke doesn't load the circuit under test in the same manner as an analogue meter (such as the Avo), the voltages readings that you get will be different from those measured under the same conditions with the Avo, making your servicing information much more difficult to interpret. There's a pretty good explanation of this phenomenon here. Another reason is that when you're twiddling a control for maximum (or minimum) output, the analogue meter tends to smooth out the voltage fluctuations that make a digital meter present a constantly-changing series of numbers, making it much easier to find a "peak" or a "dip" in voltage/current. A third reason is that many of us older members were brought up with the Avo 8 - it's a familiar and trusted old friend! HTH Cheers, Frank NB. FWIW, the Fluke range of multimeters are robust and well-respected - the Fluke 25 replaced the Avo 8 in the RAF as the general-purpose multimeter. I have both, but the Avo remains my favourite instrument. Last edited by frankmcvey; 11th Sep 2015 at 12:54 pm. |
11th Sep 2015, 1:12 pm | #63 |
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Re: Philips B3G63A
Go for a secondhand AVO8 and Fluke 25. The former often end up advertised for peanuts here, the latter turn up on eBay, but ensure that the display is working ok as they tend to dim with age and be hard to read. I bought a NOS one (i.e. 15 years old but unused) for about £30 not too long ago. It's superb, although the display is rather dark.
I grew up with digital meters so they're what I use routinely, but Frank is absolutely right. |
11th Sep 2015, 1:53 pm | #64 |
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Re: Philips B3G63A
Don't get hung up on test gear at this stage. Good equipment is satisfying to use and can make the job easier but you should concentrate on finding your way around the radio you're working on. In time you may want to invest in expensive DMMs, vintage Avos, temp controlled soldering irons, oscilloscopes and much more but you don't actually need them at this stage and they won't help your understanding of what's going on.
Lots of members of this forum have a background in professional electronics and servicing. Their expertise is absolutely invaluable, but they do tend to be accustomed to working with a full range of professional test equipment and react with horror to the idea of working with a £5 DMM. This has the unfortunate effect of suggesting to beginners that they need to buy, and learn how to use, hundreds of pounds worth of high quality servicing gear. |
11th Sep 2015, 1:56 pm | #65 | |
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Re: Philips B3G63A
Quote:
Just contemplating and pondering some stuff while I wait for my Orders to arrive... I do have other uses for such equipment over and above Vintage Radios - mainly associated with "modern" hi-fi and computing. Last edited by DonaldStott; 11th Sep 2015 at 2:06 pm. Reason: Missed a sentence |
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21st Sep 2015, 12:01 pm | #66 |
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Re: Philips B3G63A
Slow but steady progress - mainly chassis cleaning, cabinet cleaning, dial cord issues and general getting to know my way around...
I've noticed that some of the wiring that runs near and to the rear of the TI transformer is a bit worse for wear (see attached picture) with cracked or missing insulation - some of it had actually stuck to the transformer. Advice please on what to replace this with or should I just consider re-sleeving the wires in question? And what about that large resistor on the left which is a bit ropey - is that a special type (R34 1.2kΩ on Trader Sheet 1374). |
22nd Sep 2015, 11:32 am | #67 |
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Re: Philips B3G63A
Hi Donald, Pleased to see you are making good progress on the restoration.
Regarding the wires with brittle insulation, probably the easiest answer is to re-sleeve them with PVC sleeving of a comfortably snug fit around the original insulation. Re-wiring with normal equipment wire (similar to that origilally fitted) is the proper way to do it. But, being Philips, that can be a very awkward proceedure, and re-sleeving is the more hassle-free option. I dont think there are any 'hot spots' around that part of the chassis, so PVC sleeving will do Ok. The large resistor you point out is part of the HT smoothing network, and they usually look like that at this age. It will doubtlessly go on working for many years as it is. If you feel the necessity to replace it there is a suitable type here: http://www.cricklewoodelectronics.co...rs.html?page=2 Just pick out the particular value you need. My resistor is in that condition, but I do not intend to replace it, as it works fine, and is well within tolerance. Keep up the good work. Tony |
29th Sep 2015, 3:28 pm | #68 |
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Re: Philips B3G63A
I now have the "Service Manual Philips Receivers Types B3G63A, F5G62A and B5G64A" for this radio along with the "Trader Service Sheet 1374 Philips B3G63A".
I've noticed that the listed values for many of the Capacitors and Resistors are different in each case - so which one should I trust? Easy answer is to look at the component that is being replaced, but not always possible with Philip black pitch type capacitors. |
29th Sep 2015, 5:05 pm | #69 |
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Re: Philips B3G63A
Are those values really different or is the confusion caused by the circuit's being annotated differently in the two sources?
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30th Sep 2015, 9:31 am | #70 |
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Re: Philips B3G63A
Thanks Chris - you are correct of course, it's a difference in annotation just to confuse people like me!
Further complicated by the Service Manual having circuit diagrams showing options for the three different models - think I'll just stick to Trader Sheet 1374. P.S. Love the Herald signature |
3rd Oct 2015, 2:09 pm | #71 |
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Re: Philips B3G63A
Hi Donald,
Easy to get muddled when you have more than one version of the service sheet! Personally I find the Trader sheets easiest to use. My B3G63A has stopped working on long wave. The ECH81 has given up oscillating on long wave (medium wave is still perfect), so I've orderd several new (Russian) ones from an East European supplier. This supplier only sells them in 'several's, but the price is so very reasonable that I can live with that. If you find you have trouble with the same valve in your set, P.M. me and you can have one of these (when they arrive) at cost plus post. Bought singly over the net, they are rather dearer, and one is all you need for the job. Cheers, Tony |
3rd Oct 2015, 7:48 pm | #72 |
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Re: Philips B3G63A
O.k - got my capacitors replaced (at last) and had to replace one resistor which was reading more than 20% over.
I've gone through about a million cotton buds trying to get the chassis properly cleaned and tried Servisol Foam Cleaner and Isopropyl Alcohol (not at the same time of course) and the results are very mixed - the majority of the chassis is looking good but other sections are still looking grubby? Now looking at the top of the chassis, cleaned all the Valves and sprayed all contacts with Servisol Super 10. I'm now looking at the variable capacitor and wondering how to clean between the fins? Someone on YouTube used a seagull feather (!) but I'm assuming there must be a better way. Is it also advisable to oil the fin bearings?? |
3rd Oct 2015, 7:54 pm | #73 |
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Re: Philips B3G63A
Try some WD40 or even Serviso Super 10 switch cleaner to get waxy deposits off the chassis, then finish off with IPA. Don't expect perfection - it's not exactly new any more!
As for the variable cap, use compressed air, and the tiniest drop of sewing machine oil on the bearings. |
3rd Oct 2015, 7:54 pm | #74 |
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Re: Philips B3G63A
If you can, remove the variable capacitor and get it ultrasonically-cleaned. This will shift any accretion of dust/grime between the vanes, and also remove the time-hardened grease from the bearings/drive mechanism.
Then, after drying off [an oven set to 85 Centigrade], use a light oil on the bearings/gears and re-fit. You'll be amazed at the improvement in local-oscillator stability! |
3rd Oct 2015, 8:00 pm | #75 |
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Re: Philips B3G63A
You can also completely dismantle the variable cap and just wash it (really - some people put them in the dishwasher).
However, just because it looks a bit grubby does't mean there's anything wrong with it. |
4th Oct 2015, 4:22 pm | #76 |
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Re: Philips B3G63A
Hi Donald,
I would be very cautious about doing any vigourous cleaning of the tuning capacitor. The vanes are only sweated onto the shaft with solder, which is quite old now, and they can be pulled off with very little force as the solder will have lost some of it's strength. Dont ask how I know! and it's the devil's own job to refit properly, as access to the shaft is very limited on the 'inside' vanes. Ultra-sonic cleaning seems the gentlest way to go, if you really must do it. Dont forget nobody normally sees this part, so I, personally, would not fret too much about it's cosmetic looks. Do lightly oil the bearings, and use a small amount of switch cleaner on the shaft earthing spring,though. Tony |
4th Oct 2015, 6:15 pm | #77 |
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Re: Philips B3G63A
Appreciate the responses and I now have a number of options to consider - or just leave it alone until I discover there is a problem?
Meanwhile my FM dial cord just gave up the ghost - it just perished near one of the metal retaining tags next to the spring!!!! I know what's involved in re-cording ... |
12th Nov 2015, 8:54 pm | #78 |
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Re: Philips B3G63A
Hi guys - been a bit busy in the real world and have only just assembled all the components and tools I need to tackle the FM dial cord. I'll give it a go this weekend and must admit to having a few trial runs in advance!
Meantime I've been working on the damaged Bakelite case and used Isopon P38 to fill in the missing pieces and smooth over the cracks. Applied the filler in several very thin coats and sanded down between each. I won't quite get back to a mirror finish but I've gradually moved from 240 to 1200 wet and dry paper. I've attached a picture showing where I am with this. The next stage, when I'm happy with the surface finish, is to prime and paint - I'm considering Halfords Grey Primer and Halfords Vauxhall Brazil Brown?? Final question for now - I've attached a picture showing the metallised paper used as an earth inside the bottom of the cabinet which, as you can see, is a bit worse for wear! Can anyone advise what this stuff was and recommend a suitable replacement. Need to add a special thanks to Tony (boxdoctor) who has been helping me with some of my detailed questions about dial cords, pulley wheels and tuning gangs. |
12th Nov 2015, 9:43 pm | #79 |
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Re: Philips B3G63A
Donald,
I've got the same issue with the plate aerial as you on a couple of my own Philips sets. I'm going to recreate by using kitchen foil backed with lining paper (pound a roll from Poundland). I just have to work out the best glue for the job, PVA won't do. Andrew
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12th Nov 2015, 10:10 pm | #80 |
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Re: Philips B3G63A
Thanks Andrew - I had considered kitchen foil but assumed they wouldn't have used aluminium back in 1956, but I'm just guessing?
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