Audio, hi-fi and car audio - Bought an Old Valve Radio Today!

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Bought an Old Valve Radio Today!

Fleetie wrote:

Shoulda done that first. Or looked for a tube location chart
somewhere inside the radio.

No, there isn't one, and there are no markings on the PCB or stuck by
the valve bases.

Pity.

Well, I am pretty sure I have the valves in the right sockets
now. It's FAR more promising with the current line-up than it was with
any other permutation.

The valve pinouts could have helped, by giving you something to go on
regarding what sort of circuit should be connected to a given pin - a bit of
careful tracing between valve bases and power supplies / grounds can help
identify heaters, anodes and cathodes.

It could even be working, and there are no MW
or LW stations with enough signal round here, but I don't believe
that! I think it's not working.

I get the feeling that it would a pretty resilient set if it survived what
you described earlier. Got another MW radio that you can try out?

Plus I did find one pic on the net
that had the locations of two of the four valves marked, and that's
how I have it now, so that narrows things down.

Methinks the pinouts and some tracing would be a good idea.

I'm just not convinced that I haven't fried a passive component
or two.

If there was arcing in the valves, then they might be the worse for wear.
Damage to secondary components certainly can be ruled out.

No, I haven't fried a thing of beauty or value. 10 or 15 quid
seems to be about the going rate for them.

Keith might have been alluding to the rarity. All things are fixable,
however.

I paid 10 plus a
fiver postage. I think I have a valve supplier sorted, and they
seem to be less than 3 quid each, and I'm sure the audio output
valve is fine, so that's only 3 to replace, and I reckon only
one or two of them will actually need replacing.

Well, you said that you were getting noise from the speaker, so that
suggests that the o/p stage might okay.

I was a little disappointed to find it uses a PCB. I was hoping for
a chassis-based radio that I could kinda strip down to the chassis,
polish up, and have around as a cool valve radio curio that worked,
but the PCB kinda detracts from the look of the thing, really. But I'm
prepared to at least get a new set of valves and poke around some more
for dead-looking resistors.

I can understand the attraction of hard-wired valve circuits. I have a
couple of old guitar amps that don't use PCBs. I have an even older valve
radio that does.

We'll see what develops.

Indeed. Report back. :-)

--
Wally
www.makearatherlonglinkthattakesyounowhere.com
Things are always clearer in the cold, post-upload light.

Bought an Old Valve Radio Today!

Wally wrote:

If there was arcing in the valves, then they might be the worse for
wear. Damage to secondary components certainly can be ruled out.

Typo - 'certainly *can't* be ruled out'. (Sheesh!tm)

--
Wally
www.makearatherlonglinkthattakesyounowhere.com
Things are always clearer in the cold, post-upload light.

Bought an Old Valve Radio Today!

Okay, everyone a dumb moments one in a while but the chances of getting
three by chance...ummmm. In hindsight but you could have easily looked up
the valve on the web, from its probable use deducted a bit from that. i.e.
rectifier, IF, AF, mixer (Put on deer-stalker hat) Better still ask a
relevant group or get a schematic from
http://www.justradios.com/europemodels.txt and you're in with a fair chance.
You're probably okay unless you've duffed the o/p transformer. Look for
cooked / arced components, get new bottles in the right places and start all
over again.
PS Don't take on any owners ;-)

"Fleetie" wrote in message
...
So I won my first Ebay auction. I quite fancied an old valve radio. It
came
today. It's a Philips "B2G25U". (Catchy name.)

No real fault of the seller's, I suppose, but it arrived with 3 of its
4 valves out of their sockets, and rattling around in the box, but
unbroken.
But I had no way of knowing which one went into which socket, so had to
try and guess.

Wrong!

Two of the valves started arcing blue-violet inside and some unseen
passive
component emitted some (perhaps all) of its magic smoke. Turned it all off
ASAP.

Tried another permutation. Got buzzing but no stations.

Tried another permutation. Got more promising sounding buzzing and a bit
more
hopeful-sounding noise and wheezing, but no stations.

Looked the radio up on the net. Found a few pages mentioning it, but none
with much really technical info. Apparently this one is quite "unusual",
in
that it does not use an output xformer, but rather a single output valve
and a 700 or 800 ohm speaker.

Except my example DOES have an output xformer! The side connected to the
speaker says "3 - 5 Ohms". I guess maybe someone needed to replace the
speaker with a more common low-Z type, and had to put in an xformer to
match impedances. (Although the speaker does look old, and kinda looks
like it could be original, so I'm a little confused.)

This radio is only a cheap thing, dating from around 1960, built mainly
on a rather naff PCB with the valve bases and most of the passive
components
soldered into it.

I reckon I fried one or two of the valves when I plugged them into the
wrong sockets, but I know valves are more tolerant than transistors, but
they really didn't look happy arcing like that. Maybe a dead resistor too,
not sure yet.

I'll try and get hold of some replacement valves.

Hi-fi this is not, though. Although the websites I saw that mentioned the
lack of output xformer said that Philips did it to eliminate that
component
in order to improve sound quality.

WHY did I want a cheap old early-sixties valve radio? Erm, well, listening
to Kraftwerk's "Radio Activity" album again. Got me in the mood!

That was interesting, wasn't it? Cough/

Martin
--
M.A.Poyser Tel.: 07967
110890
Manchester, U.K.
http://www.fleetie.demon.co.uk

Bought an Old Valve Radio Today!

"Fleetie" wrote in message
...
So I won my first Ebay auction. I quite fancied an old valve radio. It
came
today. It's a Philips "B2G25U". (Catchy name.)

No real fault of the seller's, I suppose, but it arrived with 3 of its
4 valves out of their sockets, and rattling around in the box, but
unbroken.
But I had no way of knowing which one went into which socket, so had to
try and guess.

Wrong!

Duh, why didn't you ask the seller which tube went in which hole?

Bought an Old Valve Radio Today!

"Nath" wrote
"Fleetie" wrote in message
...
So I won my first Ebay auction. I quite fancied an old valve radio. It
came
today. It's a Philips "B2G25U". (Catchy name.)

No real fault of the seller's, I suppose, but it arrived with 3 of its
4 valves out of their sockets, and rattling around in the box, but
unbroken.
But I had no way of knowing which one went into which socket, so had to
try and guess.

Wrong!

Duh, why didn't you ask the seller which tube went in which hole?

Assumed he'd have no idea. I thought he was just trying to get shot of
something he'd had lying around for too long.

Anyway, you lot, it's all very well taking the ****, especially as I'm
so sure none of you has ever had anything similar happen to you at any
stage, and made a rash move at a time of excitement and anticipation....

Martin
--
M.A.Poyser Tel.: 07967 110890
Manchester, U.K. http://www.fleetie.demon.co.uk

Bought an Old Valve Radio Today!

Fleetie wrote:

Anyway, you lot, it's all very well taking the ****, especially as I'm
so sure none of you has ever had anything similar happen to you at any
stage, and made a rash move at a time of excitement and
anticipation....

I've never played guess the socket, but I've bought old valve radios, I've
had them blow up on me, and I've even managed the odd repair or two. If you
know how to solder and can test components, you should get there.

--
Wally
www.makearatherlonglinkthattakesyounowhere.com
Things are always clearer in the cold, post-upload light.