| Author | Message | ||
     zeitghost Frequent Contributor Username: zeitghost Post Number: 1462 Registered: 01-2006 Rating: N/A |
http://www.gi4xsf.com/philips543/543.jpg I'm busily renovating a couple of these. Typically weird Philips design with bits of string operating various switches. Thankfully, the array of buttons on the front operate wafer type switches via a horrendous lever system. Must have been designed by a genius. Got shot of 4 or 5 pitch covered wax paper "condensors" that weren't 'orrible 'Unts, but equally leaky. EZ80 lit up in most spectacular fashion as I powered it up on the variac. Good things, variacs.  Works a treat on FM now I've a) got both anodes of the EZ80 connected to the mains transformer and b) replaced the smoothing block. All I have left is replacing the dial cord & the bits of string operating the AM/FM switch, also the cord operating the rotatable internal ferrite rod. I may be some time. (Message edited by zeitghost on 27 April, 2010) | ||
| alan_stepney Frequent Contributor Username: alan_stepney Post Number: 76 Registered: 01-2008 Rating: N/A |
They sound nice and should be a useable radio when you have finished. My personal taste is that I dont like them, as I aways felt there were better options available to many/most of their products. (Not that I would have said so, as I worked for them!) They did have a habit of not doing anything simple if they could find a more complex way of doing it. | ||
| zeitghost Frequent Contributor Username: zeitghost Post Number: 1465 Registered: 01-2006 Rating: N/A |
Complex isn't the word for it. Those strings are going to be a complete nightmare, I can feel it now. The one that switches between the AM & FM detectors looks particularly evil. I'll have to remove the output transformer to get at it. And naturally enough, it consists of two bits of string with a swivel post thing in between. Deep joy. The ferrite rod adjustment looks simple enough though. The string for the tuning goes through two little pipes to get where it needs to go. I feel much swearing coming on. | ||
| alan_stepney Frequent Contributor Username: alan_stepney Post Number: 77 Registered: 01-2008 Rating: N/A |
It is alleged that the person who first devised the "cats cradle" beloved of young children, had experience of Philips radios. lol I dont know of any other maker who thinks of a design, than makes a valve to suit, as for example, a magic eye with a pentode IF amp built in. And double pentodes long before the PFL 200 was around. | ||
| zeitghost Frequent Contributor Username: zeitghost Post Number: 1467 Registered: 01-2006 Rating: N/A |
Well there's a weekend that passed without any further progress on the wireless fixing front. Ho hum. | ||
| mee Regular Contributor Username: mee Post Number: 42 Registered: 05-2010 Rating: N/A |
Looks from the date as though this thread is ended, but I'd just like to say that I had an early Philips colour TV and one of the first stereo valve radios. Both worked brilliantly when they worked, but they were a nightmare to repair. @ alan, this is not intended to be nit picking, but I don't think that the PFL 200 (mainly for TVs, hence the 'P') was, strictly speaking, a dual pentode. If it was, it would have been a PFF 200 or a PLL 200. Can't remember which letter represented the tetrode but I think it was the 'L'. Cheers, mee | ||
| alan_stepney Frequent Contributor Username: alan_stepney Post Number: 84 Registered: 01-2008 Rating: N/A |
Mee, the PFL200 was indeed a double pentode, with one section being an output pentode-hence the L. As it may be useful to others, here are the most common codes: P as a first letter indicates 300ma heaters. (Other common letters are D=1 to 1.5v usually 1.4v, E=6.3v, G=5v U=100ma For 2nd and 3rd letters, A=diode, B=double diode, C=triode, D=power triode (and could be used for tetrode), E= tetrode, F=pentode, L= power output tetrode or pentode, H=hexode/heptode, K=octode/heptode, M=tuning indicator, Y=half wave rectifier, Z=full wave rectifier. The first numbers indicates the base. This has changed over time, but the latest codes were: 2=B10B (was B8G) 3=Octal 4=B8A 5=B9D 8=B9A 9=B7G Assuming I havent mis-typed anything! | ||
| mee Regular Contributor Username: mee Post Number: 44 Registered: 05-2010 Rating: N/A |
Hi Alan. Great summary. Cheers, mee | ||
| steerpike Frequent Contributor Username: steerpike Post Number: 496 Registered: 05-2005  Rating: N/A |
Interestingly, transistors like the venerable OC71 are named by the same rules! O= zero filament voltage C= single triode 7= wired base | ||
| zeitghost Frequent Contributor Username: zeitghost Post Number: 1487 Registered: 01-2006 Rating: N/A |
Still too idle to have done anything more. I need some enthusiasm pills. | ||
| alan_stepney Frequent Contributor Username: alan_stepney Post Number: 85 Registered: 01-2008 Rating: N/A |
steerpike, yes, transistors did follow the same system, known as the Pro-electron system and used by all European manufactures. (The US had its own system.) Before transistors, 0 was used for cold cathode valves and regulators, both of which had no cathodes. A for single diodes and C for triodes, were then used for, e.g, OA91 and OC45 etc. At least it gave a clue to the identity, unlike, for example, 2SB xxxx. zeitghost, if you find some, please send me a few! | ||
| steerpike Frequent Contributor Username: steerpike Post Number: 497 Registered: 05-2005 Rating: N/A |
The 2S* type number does still give a bit of a clue: the "2" indicates a double junction, (diodes are "1") A=HF PNP, B=AF PNP, C=HF NPN, D=AF NPN, J= P-ch FET, K=N-Ch FET. | ||
| alan_stepney Frequent Contributor Username: alan_stepney Post Number: 86 Registered: 01-2008 Rating: N/A |
Ahh, didnt know that. Thanks. When I learned electronics, transistors were hardly mentioned, and although I worked with them (and even early IC's) I soon became desk-bound, and hence, out of date. Now, unless it has valves, which are fun, I lose interest as it reminds me of work. | ||
| steerpike Frequent Contributor Username: steerpike Post Number: 498 Registered: 05-2005 Rating: N/A |
And with a valve, you can mostly tell what its function is just by looking at it carefully! Unless its one of those ugly American types in a metal can. | ||
| alan_stepney Frequent Contributor Username: alan_stepney Post Number: 87 Registered: 01-2008 Rating: N/A |
That's true. Also, when things go wrong you can just follow the smoke, and it will all still work afterwards. (Unlike those 3-legged fuses.) | ||
| zeitghost Frequent Contributor Username: zeitghost Post Number: 1489 Registered: 01-2006 Rating: N/A |
"Before transistors, 0 was used for cold cathode valves and regulators, both of which had no cathodes" Er. they have cathodes. What they don't have is heaters. Found a brand new OC71 in the junk room. And a selection of obscure & very obsolete AEI transistors & triacs. Also have some GET transistors in the stores that are nearly as old as I am. Not to mention the odd BCZ11 which has 3 leads and looks like an OC81. | ||
| alan_stepney Frequent Contributor Username: alan_stepney Post Number: 89 Registered: 01-2008 Rating: N/A |
Oh dear, Silly of me. The brain cell was switched off today. A cold cathode valve without a cathode would be...? Should have got it right as I was fitting one yesterday. I too have some Ge transistors & diodes. Not sure how many are good (even though they are new) due to the "tin whisker" problem. Oh and some of the Plessey IC's as used by Sinclair. Wonder if they still work? | ||
| zeitghost Frequent Contributor Username: zeitghost Post Number: 1511 Registered: 01-2006 Rating: N/A |
Truly nightmarish to set up the various bits of string in this thing. Getting the replacement cord for the AM/FM switch the right length was a grade A pain in the backside. Ho hum. | ||
| zeitghost Frequent Contributor Username: zeitghost Post Number: 1513 Registered: 01-2006 Rating: N/A |
The backside pain continued after the lacing cord stretched in the heat & the AM/FM switching bit the dust. Again. Then I tried a bit of insulated stranded wire that I prestretched before fitting. The joy of elderly electronics. | ||
| steerpike Frequent Contributor Username: steerpike Post Number: 515 Registered: 05-2005 Rating: N/A |
I have a Philips that uses an array of coiled cable-pulls (just like a bicycle brake cable) to link the pushbuttons to the switches internally. When the iner cores snapped, I found steel guitar strings were a good substitute. | ||
| alexr Frequent Contributor Username: alexr Post Number: 141 Registered: 02-2008 Rating: N/A |
Many years ago I used to maintain a chart digitiser where the chart trace was manually tracked with a cursor as the chart rolled through the machine. The cursor control was very much like a radio dial (but had bigger and better knobs) and what we used for stringing the cursor was a plastic coated multi-strand stainless steel wire. The same wire is used for stringing beads and necklaces, its generic name I think is Tigertail and it comes in various thicknesses and strand configurations. Its usually fastened using tubular crimps. You can get it and the crimps from beading or jewellery suppliers. Also beading/jewellery suppliers carry an assortment of stringing materials ranging from nylon though to braided silk which could be pressed into use for radio dial strings. (Message edited by Alexr on 02 September, 2010) Alex | ||
| zeitghost Frequent Contributor Username: zeitghost Post Number: 1518 Registered: 01-2006 Rating: N/A |
Thanks for that, Alexr. Most useful. The original braided steel wire used crimped beady thingies. I just tied knots. Which obviously didn't cut the proverbial mustard. | ||
| zeitghost Frequent Contributor Username: zeitghost Post Number: 1533 Registered: 01-2006 Rating: N/A |
Which reminds me that now the plumber has buggered off with a wodge of my hard earned, it's time to see if those wireless sets still work & if so, give them back. | ||
| zeitghost Frequent Contributor Username: zeitghost Post Number: 1546 Registered: 01-2006 Rating: N/A |
I still haven't given that guy his wireless sets back.  They both still work too. | ||
| zeitghost Frequent Contributor Username: zeitghost Post Number: 1630 Registered: 01-2006 Rating: N/A |
The assembled congregation may be interested to know that the chap got his wireless sets back. And I got an MOT for nothing. |
