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

"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, you are a wattock! Get onto rec.antiques.radio+phono immediately and
re-confess your sins.

If you are lucky someone will put you right. If, OTOH, you have fried a
thing of great rarity and beauty expect them to send someone round in
shades, dark suit, white shirt, black Slim Jim tie and an earpiece with a
curly cord in one ear......

"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, you are a wattock! Get onto rec.antiques.radio+phono immediately and
re-confess your sins.

If you are lucky someone will put you right. If, OTOH, you have fried a
thing of great rarity and beauty expect them to send someone round in
shades, dark suit, white shirt, black Slim Jim tie and an earpiece with a
curly cord in one ear......

Fleetie wrote:

But I had no way of knowing which one went into which
socket, so had to try and guess.

Guess = bad move.


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.

Mad.


Looked the radio up on the net.

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


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

A circuit diagram, or a generic diagram for a radio using the same valves,
would be a good idea. Specs/pinouts of the valves as well.


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

"Wally"
Fleetie wrote:

Looked the radio up on the net.

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.

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

A circuit diagram, or a generic diagram for a radio using the same valves,
would be a good idea. Specs/pinouts of the valves as well.

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. 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. 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.

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

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

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.

We'll see what develops.


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

"Fleetie" wrote

snip

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


OK, it ain't always about the bloody money....


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.

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.

We'll see what develops.



That's the ticket! :-)

(I'm not normally given to excessive anthropomorphism, but I do see these
little critters as sometimes needing a helping hand, rather than just
chucking them out. The one you've got has survived 40 years or so
already.....!!)

These UK links might be interesting/useful:

http://www.radiovs.co.uk/ (specifically
http://www.radiovs.co.uk/philips_b2g25u.htm)

http://www.radiobygones.co.uk

http://www.vintage-radio.com/index.shtml

http://www.bvws.org.uk/


Let us know how you get on with it.

"Fleetie" wrote

snip

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


OK, it ain't always about the bloody money....


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.

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.

We'll see what develops.



That's the ticket! :-)

(I'm not normally given to excessive anthropomorphism, but I do see these
little critters as sometimes needing a helping hand, rather than just
chucking them out. The one you've got has survived 40 years or so
already.....!!)

These UK links might be interesting/useful:

http://www.radiovs.co.uk/ (specifically
http://www.radiovs.co.uk/philips_b2g25u.htm)

http://www.radiobygones.co.uk

http://www.vintage-radio.com/index.shtml

http://www.bvws.org.uk/


Let us know how you get on with it.

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.

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.

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.