The first pocket transistor radio

[jackinnj]

for your Sunday evening enjoyment, during halftime for the Superbowl:

http://people.msoe.edu/~reyer/regency/

 

[anatech]

Hi jackinnj,
Cool

I have a portable transistor radio from 1959 in it's original box with manual. I'll post a pic if I can find it.

-Chris

 

[Tube_Dude]

for your Sunday evening enjoyment

Hi jackinnj

Thanks for the link and I remark , how lucky we are in present times.Look at the data sheet of this TI transistor...

-current amplification factor ( minimum ) - 0,9

http://people.msoe.edu/~reyer/regency/ti_ad_11-53.jpg

 

[Steve Eddy]

Re: Re: The first pocket transistor radio

-current amplification factor ( minimum ) - 0,9

Hehehe. And I like this from the TI information bulletin:

The transistors - technically known as n-p-n grown germanium triodes - are made in the Semiconductor Products Division

I've always said transistors are triodes too!

And just look at this output stage:

An externally hosted image should be here but it was not working when we last tested it.

It's a germanium SET amp!

se

 

[anatech]

Hi Steve,
You just started the next revival. Everyone knows true class "A" is the best sound.

Remember the old EV PA amps in the early 70's? Classic class "A", germanium output transistors. Nice coming in from the cold in the winter.

-Chris

 

[Tube_Dude]

Re: Re: Re: The first pocket transistor radio

I've always said transistors are triodes too!


It's a germanium SET amp!

Triodes only for the 3 terminals , because the impedance "looking" in the collector of the transistor is very high ( hundreds of KOhms ) it look more , like a pentode .

In the schematic you provide (without feedback) , we have a transconductance output stage and the speaker is in current drive mode ...

 

[davidsrsb]

If germanium devices got more than a little warm they died.

 

[Mark A. Gulbrandsen]

I just love that T.I. ad from the 50's... "20 Times Tested" Today you're lucky if they test every 20,000th device!

Mark

 

[Steve Eddy]

You just started the next revival. Everyone knows true class "A" is the best sound.

Hehehe. Already did some noodling around with some germaniums. Too damned twitchy for my tastes.

Remember the old EV PA amps in the early 70's? Classic class "A", germanium output transistors. Nice coming in from the cold in the winter.

Yeah, and the bias on those things probably went out of wack just from the bit of cold air that blew through the door.

se

 

[Steve Eddy]

Re: Re: Re: Re: The first pocket transistor radio

Triodes only for the 3 terminals , because the impedance "looking" in the collector of the transistor is very high ( hundreds of KOhms ) it look more , like a pentode .

I don't care. It has three terminals. It's a !@#$% TRIODE, DAMMIT!

In the schematic you provide (without feedback) , we have a transconductance output stage and the speaker is in current drive mode ...

Yeah. Gonna get me one of those little critters and rip out all the other crap and use the output stage to drive a 16 ohm compression driver on a very efficient horn.

se

 

[Steve Eddy]

If germanium devices got more than a little warm they died.

Yeah, they were hardly the most robust solid state devices.

se

 

[Tube_Dude]

I just love that T.I. ad from the 50's...

November 1953...two month after I was born ...in september 1953...

 

[Steve Eddy]

I just love that T.I. ad from the 50's... "20 Times Tested" Today you're lucky if they test every 20,000th device!

Yeah. But materials processing and manufacturing have come a long way since then too.

se

 

[clem_o]

My brother has a Sony radio from 1972 - if I recall its supposed to have been a 'first IC radio'. About as big as a match-box. I remember seeing it when I was a lot younger, not sure if its still around!

Cheers!

 

[jackinnj]

i didn't get my first transistor radio until 1961 -- my dad gave me his when he purchased a new one -- it was a 7-transistor GE model and it is somewhere in my mother's house! Up until I received this radio I used a crystal set from a Remco kit to listen to the late-night talkers and baseball.


http://people.msoe.edu/~reyer/regency/QST_3-53-p97.jpg

 

[SY]

Jack, you're probably old enough to remember the transistor wars? This is a 10 transistor radio, for another $5 you can get a 15 transistor radio. Top of the line is a 20 transistor radio; that one must REALLY be good!

One of the electronics mags at the time (Electronics Illustrated, I think) ran an expose, where they bought a bunch of the high transistor count radios, examined the guts, and found about 5 transistors actually working, the rest either diode connected or not connected at all.

 

[dnsey]

Rather like the 'stereo' ones, which had one speaker mounted in the centre of a cardboard tube, with grilles at each end!

Who mentioned BO**

 

[Burnedfingers]

What I remember the most was how long the battery lasted in one of the old transistor radios. The more transistors the less life on the old 9 volt. I had one that would spend a battery in about an hour.

 

[davidsrsb]

Re: Re: Re: Re: The first pocket transistor radio

Triodes only for the 3 terminals , because the impedance "looking" in the collector of the transistor is very high ( hundreds of KOhms ) it look more , like a pentode .

Germaniums had much lower output resistance than silicon transistors, far more like a triode.

I remember a physics practical around 1971 measuring transistor curves. The task was written with an AC128 germanium in mind and I was very confused by the silicon device that I was given.

 

[Tube_Dude]

Re: Re: Re: Re: Re: The first pocket transistor radio

Germaniums had much lower output resistance than silicon transistors, far more like a triode.

Look at the specifications in the data sheet.

http://people.msoe.edu/~reyer/regency/ti_ad_11-53.jpg

Collector resistance (minimum ) ... 0,2 MOhms - 0,4 MOhms..

The proverbial imperfect constant current source , hardly a triode at all , I'm afraid...

Cheers