Transistor Developments 1953

In article , Marky P wrote:
Valves continued to be used for 'quality' devices up to the end of the*
sixties and beyond, especially for static, mains operated devices.

Of course, vales are still used today in some high end audio
equipment, but are they any different to the valves of yesteryear?

Yes. Some of them are probably thirty years older, because they *are* the
valves of yesteryear.

Rod.

"Max Demian" wrote in message
...
"Ivan" wrote in message
.uk...

A bit off topic for digital newsgroup I know, but just in case any other
old timers are interested I've OCRd the editorial from the January 1953
edition of Practical Television about the then state of transistor
technology.

PRACTICAL TELEVISION & "TELEVISION TIMES"
Editor: F. J. CAMM

JANUARY 1953
EVERY MONTH
Vol. 3 No. 32

snip

Well it took a long time for these uses of transistors to become
practicable (or commonly available):

* TVs - I think the late sixties for all-transistor 12" mains
transportables - and a few battery operated ones with smaller screens.

Didn't Sony do one in 1959?


* AM transistor radios - late fifties.

* FM radios - mid sixties.

Whilst I have a ~1959 valve FM radio, that worked until fairly recently, I
am pretty sure that there were transistor ones by the early sixties.


* Car radios - early seventies - they continued to use valves in 'hybrid'
radios into the seventies with a single power output transistor and valves
with 12V HT and LT to avoid the need for a vibrator power pack - of course
they couldn't do this in America as most cars had 6V batteries.

* Transformerless power amplifiers - seventies I think.

It's a lot easier to make an experimental device that isn't expected to
work very well.

Valves continued to be used for 'quality' devices up to the end of the
sixties and beyond, especially for static, mains operated devices.

Quad had a valve amp for a long time and there were lots of tellies with
valves in well into the seventies.



--
Max Demian

On Wed, 21 Nov 2007 03:11:16 -0000, "Bill Wright"
wrote:

"Ivan" wrote in message
o.uk...
PRACTICAL TELEVISION & "TELEVISION TIMES"
Editor: F. J. CAMM

By gum it takes yer back! Cutting your HT leads and screwing them brown
ceramic tubes with resistors inside 'em into the ends of the cable! Then
revving up the van and seeing that all the tellys in the street fall over,
just like they did before!


I can also remember "Suppressor Caps", "Suppressor Plugs" and
"Suppressor Cable". None of which when fitted to an old A35 van seemed
to last more than a few months.

I stopped at the side of the M1 in desperation at about 21-45 one
night because my van was running on 3 cylinders then 2, the 1, just
after I'd just changed the coil, plugs, and distributor cap, not to
mention "The points" and "The Condenser".

Underneath the bonnet was like a firework display with EHT tracking
all over the coil, distributor cap and spark plug wiring. Cause was
bad suppressor caps, quick spray with Ambersil MS4 got me going to get
home. I cut one open, the resistor element had turned to white powder.

TBH I had resorted to MS4 to get me going before, but this was the
first instance it had happened in the dark so I could see what was
happening.

DG

"Max Demian" wrote in message
...
"Ivan" wrote in message
.uk...

A bit off topic for digital newsgroup I know, but just in case any other
old timers are interested I've OCRd the editorial from the January 1953
edition of Practical Television about the then state of transistor
technology.

PRACTICAL TELEVISION & "TELEVISION TIMES"
Editor: F. J. CAMM

JANUARY 1953
EVERY MONTH
Vol. 3 No. 32

snip

Well it took a long time for these uses of transistors to become
practicable (or commonly available):

* TVs - I think the late sixties for all-transistor 12" mains
transportables - and a few battery operated ones with smaller screens.


http://www.thevalvepage.com/tv/perdio/portorama/portorama.htm

Much beloved by the travelling community in the early 1960s, the AU103
LOTransistor was the most common cause of set failure IIRC.




--
Max Demian

On Wed, 21 Nov 2007 09:29:35 -0000, "Chas Gill"
wrote:

I bought a red spot in 1957 (IIRC) at my local radio hobby shop. Again,
IIRC it cost 17/6d (83p) and - as a tender 11 year old - that represented
many weeks pocket money! The intention was to provide my much-loved crystal
set with a single stage audio amplifier. Inevitably I connected it the
"wrong way round"

It wasn't that uncommon for the "Red Spot" to eventually wear off
eventually causing that problem.

and it got very hot and actually melted! I was
permanently scarred by this experience and have double-checked everything
ever since.........................


Don't eat your heart out over it.

The wires would have dropped off it where they enter the glass seal
after a couple of weeks schoolboy experimentation, especially if your
circuits didn't work. Fault finding required much soldering /
de-soldering / re-soldering to check the device out of circuit with a
meter.

Many of the circuits published in hobbyist handbooks and mags weren't
about to work due to the very crappy devices anyway.

DG

On Wed, 21 Nov 2007 11:29:50 -0000, "Max Demian" wrote:


Well it took a long time for these uses of transistors to become practicable
(or commonly available):

* TVs - I think the late sixties for all-transistor 12" mains
transportables - and a few battery operated ones with smaller screens.

Perdio went into production with the first battery/mains television portable
(Portorama Mark 2) in 1962. Apart from the tube it contained an EHT rectifier
(DY86).
It was based on a Mullard reference design. I hand-drew the IF,frame and audio
pcbs.


Geo

On Wed, 21 Nov 2007 15:07:19 +0000, "Clive."
wrote:

In message , Bill Wright
writes
By gum it takes yer back! Cutting your HT leads and screwing them brown
ceramic tubes with resistors inside 'em into the ends of the cable! Then
revving up the van and seeing that all the tellys in the street fall over,
just like they did before!
That must have been some time ago, it sounds as if all the TVs were hard
locked line sync rather than the flywheel type common from the 60s.

IIAC It wasn't really the syncs. Ignition intereference drove the beam
current as hard on as the set design would permit. Enough to cause the
beam to become defocussed and cause white splodges several lines wide
at each spark. This had the appearance of horizontal lines of big
white spots which ran up and/or down the screen according to the speed
of the car engine / sewing machine etc motor. FWIR Some sets had a
peak white clipper adjustment brought out to the back of the set as a
user control, but *NO* users knew how to set it.

IIAC Flywheel sync came along with the 625 line standard and negative
modulation. Splashes of ignition interference instead of looking like
peak white splodges looked like sync pulses. Flywheel sync sorted
that.

I think it appeared in the dearest 405 line only sets in the run-up to
625 as a selling point as it was "Better", like TV aerials made out of
sliver ;-)

DG

On Wed, 21 Nov 2007 18:44:28 -0000, "R. Mark Clayton"
wrote:


Valves continued to be used for 'quality' devices up to the end of the
sixties and beyond, especially for static, mains operated devices.

Quad had a valve amp for a long time and there were lots of tellies with
valves in well into the seventies.


I don't want to bring a great wave of sadness and gnashing of teeth to
the group but I read in the last week that the "Quad" trade name had
been sold on to the same Chinese outfit that now owns "Warfedale".

Sic transit gloria mundi.

DG

On Wed, 21 Nov 2007 08:49:20 GMT, "Brian Gaff"
wrote:

Anyone recall the first transistors available to hobbyists. They were known
as red spot, and most appeared to be vastly different from each other in
gain, noise and frequency of operation.

Little square silver things with three wires.


That sounds like the GEC effort which was a regular transistor in a
metal envelope like a liquorice comfit pressed into a square heatsink.

Red/yellow spot could manage lf radio reception, but later the innovative
'point contact transistor managed higher frequencies, but were notoriously
prone to death.

Point contact transistor technology was the original research concept,
it demonstrated a semiconductor device could have gain. That was the
end of it, it was never commercially useful or at any rate expoited.

Germanium alloy diffused transistors (as made in the UK) could be made
to operate at higher frequencies, this was clear from day 1, but the
junctions had to be made thinner and smaller (less capacitance and
charge storage). It was all about producing in-spec devices at an
affordable price, but they were still Germanium alloy diffused
transistors.

By about 1965 Wireless world had published a design for a conventional
VHF -FM superhet radio using the Mullard AF 11* series transistors,
and VHF band III tv tuners were using germanium transistors in common
base mode in all stages. The silicon BF series soon came along.

Anyone interested in the history of the British semiconductor
industry, and what happened to it could well look at this thread in
Google Groups : http://snipurl.com/1u0g0 And in particular Peter
Duck's two contributions to it. He worked for GEC semiconductors then.

DG

"R. Mark Clayton" wrote in message
...

"Max Demian" wrote in message
...
"Ivan" wrote in message
.uk...

A bit off topic for digital newsgroup I know, but just in case any other
old timers are interested I've OCRd the editorial from the January 1953
edition of Practical Television about the then state of transistor
technology.

PRACTICAL TELEVISION & "TELEVISION TIMES"
Editor: F. J. CAMM

JANUARY 1953
EVERY MONTH
Vol. 3 No. 32

snip

Well it took a long time for these uses of transistors to become
practicable (or commonly available):

* TVs - I think the late sixties for all-transistor 12" mains
transportables - and a few battery operated ones with smaller screens.

Didn't Sony do one in 1959?


* AM transistor radios - late fifties.

* FM radios - mid sixties.

Whilst I have a ~1959 valve FM radio, that worked until fairly recently, I
am pretty sure that there were transistor ones by the early sixties.


* Car radios - early seventies - they continued to use valves in 'hybrid'
radios into the seventies with a single power output transistor and
valves with 12V HT and LT to avoid the need for a vibrator power pack -
of course they couldn't do this in America as most cars had 6V batteries.

* Transformerless power amplifiers - seventies I think.

It's a lot easier to make an experimental device that isn't expected to
work very well.

Valves continued to be used for 'quality' devices up to the end of the
sixties and beyond, especially for static, mains operated devices.

Quad had a valve amp for a long time and there were lots of tellies with
valves in well into the seventies.



--
Max Demian


This is the first all transistor TV I ever saw (OK it did have one valve)
It was on a cabin-curser we hired on the Norfolk Broads.
http://www.thevalvepage.com/tv/perdi.../portorama.htm
Later I owned one of these sets.

--

Graham

%Profound_observation%