Battery powered TUBED megaphone

[t.hoehler]

Hi group, do any of you old timers, like me :o), ever remember seeing an
electronic megaphone from the 50's that was brown hammertone, named LOUD
HAILER on the side, used vacuum tubes and A & B batteries? I swear, my
scoutmaster had one when I was in Troop 4 waaaay back in 1962 or so. It had
three tubes, a pair of push pull outputs and a preamp. I think they were the
3 volt filament tubes like the ones in the big ol' portables of that era. It
was not a powerhouse, but as a kid I thought it was the neatest thing. When
you squeezed the trigger, it took about a second for the tubes to warm up
before you could use it. As I recall, used two 671/2 volt batteries and a
couple of D cells to light the tubes. I would really like to find one of
these, the solid state Fanons would blow this guy out of the water, but this
thing was classy.
Regards,
Tom

[John Stewart]

patrick wrote:

> "John Stewart" > schreef in bericht
> ...
> >
> >
> > "t.hoehler" wrote:
> >
> > > Hi group, do any of you old timers, like me :o), ever remember seei=
ng an
> > > electronic megaphone from the 50's that was brown hammertone, named=
LOUD
> > > HAILER on the side, used vacuum tubes and A & B batteries? I swear=
, my
> > > scoutmaster had one when I was in Troop 4 waaaay back in 1962 or so=
=2E It
> had
> > > three tubes, a pair of push pull outputs and a preamp. I think they=
were
> the
> > > 3 volt filament tubes like the ones in the big ol' portables of tha=
t
> era. It
> > > was not a powerhouse, but as a kid I thought it was the neatest thi=
ng.
> When
> > > you squeezed the trigger, it took about a second for the tubes to w=
arm
> up
> > > before you could use it. As I recall, used two 671/2 volt batteries=
and
> a
> > > couple of D cells to light the tubes. I would really like to find o=
ne of
> > > these, the solid state Fanons would blow this guy out of the water,=
but
> this
> > > thing was classy.
> > > Regards,
> > > Tom
> >
> > Probably a 1J6G dual Triode running Class B driven by a 1H4G.
> > Mic would be a carbon job something like what is in a Bell handset.
> > If everything worked you could probably get a dependable 1.5 Watts
> > after output transformer losses.
> >
> > Cheers, John Stewart
> >
> Tom,
>
> I think I have the microphone cell for a loudhailer.
> It is an unusual looking element, a 55mm (2 1/4") diameter by 12mm (1/2=
")
> thick brown backelite disk having 2 terminals on the back. The front is=

> devided in 2 sections and filled with a black material and sealed with
> transparant plastic foil. The divider has 2 rectangular gold patches.
> The resistance between the terminals (about 500 Ohm at rest) is very
> sensitive to pressing the foil.
> One had a very old handwritten label that I just now could decipher to =
be
> "spareparts for micro for loudhailer"
> I couldn't imagine this was a microphone cell... till now. I will try a=
nd
> hear what sound this can produce one of these days...
> It's marked on the back
> Technical & Research Processes Ltd. London
> A.P.W. 2045
> W.D.CAT:
> N=B0 Z.B/M.94.0002
>
> Patrick

That sounds like a carbon mic element.
Needs a bit of DC current applied to operate. JLS

[Neutrodyne]

>Subject: Re: Battery powered TUBED megaphone
>From: "patrick"
>Date: 8/1/2003 5:37 PM Central Daylight Time
>Message-id: >
>
>
>"John Stewart" > schreef in bericht
...
>
>
>patrick wrote:
>
>> "John Stewart" > schreef in bericht
>> ...
>> >
>> >
>> > "t.hoehler" wrote:
>> >
>> > > Hi group, do any of you old timers, like me :o), ever remember seeing
>an
>> > > electronic megaphone from the 50's that was brown hammertone, named
>LOUD
>> > > HAILER on the side, used vacuum tubes and A & B batteries? I swear,
>my
>> > > scoutmaster had one when I was in Troop 4 waaaay back in 1962 or so.
>It
>> had
>> > > three tubes, a pair of push pull outputs and a preamp. I think they
>were
>> the
>> > > 3 volt filament tubes like the ones in the big ol' portables of that
>> era. It
>> > > was not a powerhouse, but as a kid I thought it was the neatest thing.
>> When
>> > > you squeezed the trigger, it took about a second for the tubes to warm
>> up
>> > > before you could use it. As I recall, used two 671/2 volt batteries
>and
>> a
>> > > couple of D cells to light the tubes. I would really like to find one
>of
>> > > these, the solid state Fanons would blow this guy out of the water,
>but
>> this
>> > > thing was classy.
>> > > Regards,
>> > > Tom
>> >
>> > Probably a 1J6G dual Triode running Class B driven by a 1H4G.
>> > Mic would be a carbon job something like what is in a Bell handset.
>> > If everything worked you could probably get a dependable 1.5 Watts
>> > after output transformer losses.
>> >
>> > Cheers, John Stewart
>> >
>> Tom,
>>
>> I think I have the microphone cell for a loudhailer.
>> It is an unusual looking element, a 55mm (2 1/4") diameter by 12mm (1/2")
>> thick brown backelite disk having 2 terminals on the back. The front is
>> devided in 2 sections and filled with a black material and sealed with
>> transparant plastic foil. The divider has 2 rectangular gold patches.
>> The resistance between the terminals (about 500 Ohm at rest) is very
>> sensitive to pressing the foil.
>> One had a very old handwritten label that I just now could decipher to be
>> "spareparts for micro for loudhailer"
>> I couldn't imagine this was a microphone cell... till now. I will try and
>> hear what sound this can produce one of these days...
>> It's marked on the back
>> Technical & Research Processes Ltd. London
>> A.P.W. 2045
>> W.D.CAT:
>> N° Z.B/M.94.0002
>>
>> Patrick
>
>That sounds like a carbon mic element.
>Needs a bit of DC current applied to operate. JLS
>
>John,
>
>The weard thing is that the carbon is solid (sintered?), not the usual
>powder or flakes I've seen in some of these.
>
>Patrick

Some used the carbon mic with a battery in series directly into a
transformer/speaker horn or a speaker horn with a 200 ohm voice coil directly.
As I remember the mic elements, they were quite robust to handle the current
involved.
Neutrodyne