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Have One ? "Regency TR-1" - Orig Commercial Transistor Radio

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  Have One ? "Regency TR-1" - Orig Commercial Transistor Radio c186282 <c186282@nnada.net> - 2025-08-16 01:15 -0400
    Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio The Natural Philosopher <tnp@invalid.invalid> - 2025-08-16 10:31 +0100
    Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio John McCue <jmclnx@gmail.com.invalid> - 2025-08-20 15:30 +0000
      Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio "Carlos E.R." <robin_listas@es.invalid> - 2025-08-20 22:38 +0200
        Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio c186282 <c186282@nnada.net> - 2025-08-20 23:59 -0400
      Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio not@telling.you.invalid (Computer Nerd Kev) - 2025-08-21 08:02 +1000
      Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-21 06:52 +0000
        Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio c186282 <c186282@nnada.net> - 2025-08-21 03:34 -0400
        Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio "Carlos E.R." <robin_listas@es.invalid> - 2025-08-21 12:28 +0200
          Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio c186282 <c186282@nnada.net> - 2025-08-22 09:41 -0400
            Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio The Natural Philosopher <tnp@invalid.invalid> - 2025-08-22 19:14 +0100
              Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio "Carlos E.R." <robin_listas@es.invalid> - 2025-08-22 20:37 +0200
                Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio The Natural Philosopher <tnp@invalid.invalid> - 2025-08-22 20:00 +0100
                  Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio "Carlos E.R." <robin_listas@es.invalid> - 2025-08-22 22:36 +0200
                    Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio The Natural Philosopher <tnp@invalid.invalid> - 2025-08-22 21:58 +0100
                    Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio c186282 <c186282@nnada.net> - 2025-08-23 02:42 -0400
                      Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio The Natural Philosopher <tnp@invalid.invalid> - 2025-08-23 11:22 +0100
                        Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio rbowman <bowman@montana.com> - 2025-08-23 21:06 +0000
                        Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio c186282 <c186282@nnada.net> - 2025-08-24 02:22 -0400
                          Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio The Natural Philosopher <tnp@invalid.invalid> - 2025-08-24 10:53 +0100
                      Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio "Carlos E.R." <robin_listas@es.invalid> - 2025-08-24 00:22 +0200
                        Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio rbowman <bowman@montana.com> - 2025-08-24 05:10 +0000
                  Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio rbowman <bowman@montana.com> - 2025-08-23 06:00 +0000
                    Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio The Natural Philosopher <tnp@invalid.invalid> - 2025-08-23 11:15 +0100
                      Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio rbowman <bowman@montana.com> - 2025-08-23 21:32 +0000
                        Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio The Natural Philosopher <tnp@invalid.invalid> - 2025-08-24 10:44 +0100
                          Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio c186282 <c186282@nnada.net> - 2025-08-24 05:51 -0400
                    Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2025-08-23 18:02 +0000
                      Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio rbowman <bowman@montana.com> - 2025-08-23 21:34 +0000
                        Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2025-08-24 00:18 +0000
                      Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-23 23:24 +0000
                      Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio c186282 <c186282@nnada.net> - 2025-08-24 04:02 -0400
                Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio c186282 <c186282@nnada.net> - 2025-08-22 23:06 -0400
                  Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio The Natural Philosopher <tnp@invalid.invalid> - 2025-08-23 11:11 +0100
                    Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio c186282 <c186282@nnada.net> - 2025-08-24 01:53 -0400
              Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio c186282 <c186282@nnada.net> - 2025-08-22 23:01 -0400
                Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio The Natural Philosopher <tnp@invalid.invalid> - 2025-08-23 11:05 +0100
                  Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-23 10:20 +0000
                  Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio "Carlos E.R." <robin_listas@es.invalid> - 2025-08-24 00:27 +0200
                    Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio The Natural Philosopher <tnp@invalid.invalid> - 2025-08-24 10:49 +0100
                      Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio rbowman <bowman@montana.com> - 2025-08-24 21:28 +0000
                        Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio The Natural Philosopher <tnp@invalid.invalid> - 2025-08-25 12:23 +0100
                          Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio c186282 <c186282@nnada.net> - 2025-08-26 03:32 -0400
                  Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio c186282 <c186282@nnada.net> - 2025-08-24 01:40 -0400
            Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio "Carlos E.R." <robin_listas@es.invalid> - 2025-08-22 20:35 +0200
              Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-22 22:26 +0000
                Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio "Carlos E.R." <robin_listas@es.invalid> - 2025-08-23 01:29 +0200
                  Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-23 00:23 +0000
                  Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio The Natural Philosopher <tnp@invalid.invalid> - 2025-08-23 11:01 +0100
                    Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-23 10:19 +0000
                Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio rbowman <bowman@montana.com> - 2025-08-23 06:04 +0000
                  Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio The Natural Philosopher <tnp@invalid.invalid> - 2025-08-23 11:16 +0100
                    Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio rbowman <bowman@montana.com> - 2025-08-23 21:08 +0000
                    Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio "Carlos E.R." <robin_listas@es.invalid> - 2025-08-24 00:30 +0200
                    Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio c186282 <c186282@nnada.net> - 2025-08-24 02:14 -0400
                  Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2025-08-23 18:02 +0000
                    Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio c186282 <c186282@nnada.net> - 2025-08-24 03:51 -0400
                      Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio rbowman <bowman@montana.com> - 2025-08-24 21:19 +0000
            Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio rbowman <bowman@montana.com> - 2025-08-22 19:48 +0000
              Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio The Natural Philosopher <tnp@invalid.invalid> - 2025-08-22 21:57 +0100
                Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio rbowman <bowman@montana.com> - 2025-08-23 06:25 +0000
                  Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio The Natural Philosopher <tnp@invalid.invalid> - 2025-08-23 11:20 +0100
                    Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio rbowman <bowman@montana.com> - 2025-08-23 21:45 +0000
                      Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio The Natural Philosopher <tnp@invalid.invalid> - 2025-08-24 10:46 +0100
                    Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-23 23:29 +0000
                      Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio rbowman <bowman@montana.com> - 2025-08-24 04:30 +0000
                  Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2025-08-23 18:02 +0000
                    Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio rbowman <bowman@montana.com> - 2025-08-23 21:49 +0000
                      Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2025-08-24 00:18 +0000
                        Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio rbowman <bowman@montana.com> - 2025-08-24 04:59 +0000
                          Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2025-08-24 19:19 +0000
                        Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio The Natural Philosopher <tnp@invalid.invalid> - 2025-08-24 10:47 +0100
                          Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2025-08-24 19:19 +0000
                          Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-24 22:13 +0000
                Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio c186282 <c186282@nnada.net> - 2025-08-23 03:15 -0400
              Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio c186282 <c186282@nnada.net> - 2025-08-23 02:25 -0400
        Re: Have One ? "Regency TR-1" - Orig Commercial Transistor Radio rbowman <bowman@montana.com> - 2025-08-21 20:37 +0000

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#72085

On 2025-08-23 08:42, c186282 wrote:
> On 8/22/25 4:36 PM, Carlos E.R. wrote:
>> On 2025-08-22 21:00, The Natural Philosopher wrote:
>>> On 22/08/2025 19:37, Carlos E.R. wrote:
>>>> On 2025-08-22 20:14, The Natural Philosopher wrote:
>>>>> On 22/08/2025 14:41, c186282 wrote:
>>>>>>
>>>>>>> I got this one when I went to uni:
>>>>>>>
>>>>>>> <https://www.etsy.com/es/listing/1791229461/vintage-sanyo- 
>>>>>>> transistor- radio-amfm> 
>>>>>>
>>>>>>    I remember those !  🙂
>>>>>>
>>>>>>    Alas most of those little old radios had rather
>>>>>>    poor sensitivity plus poor selectivity.
>>>>>>
>>>>> Actually selectivity came easy as adding transistors was way 
>>>>> cheaper than adding valves.
>>>>
>>>> It came from adding intermediate frequency transformer stages, which 
>>>> were not cheap nor easy to adjust.
>>>
>>> They were cheap and they were *really* easy to adjust.
>>>
>>> I build several portable radios.
>>
>> Time consuming.
>>
>> I built just one.
> 
>    You can get lots of perfectly good circuits off
>    the net - plenty options/paradigms to choose from.
> 
>    It's interesting to do.
> 
>    However to do most RIGHT you DO need some proper
>    and expensive instrumentation - scopes, LCR meters
>    and such, maybe an audio spectrum meter. Few have
>    those things.

Exactly.

I built myself, from a kit, a good CB receiver (AM only). Among other 
things, I learned that part of the critical stuff is unobtainable. 
Specially the transformers and variable caps. A kit solves all that., 
but there are no more kits like that one.

And I did not have the instrumentation.

I lost the receiver, I think it was stolen.

Maybe this one:
<https://www.radiomuseum.org/r/saleskit_transceiver_cb_40a_1973.html#b>

> 
>    If I'm gonna do another it'll be a 'super-regenerative',
>    the kind that tend to howl a bit. Interesting feedback
>    paradigm.
> 
>    You can do good AM with plain old 2N222A's up to
>    maybe 5Mhz. Super cheap.


-- 
Cheers, Carlos.

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#72111

On Sun, 24 Aug 2025 00:22:10 +0200, Carlos E.R. wrote:

> I built myself, from a kit, a good CB receiver (AM only). Among other
> things, I learned that part of the critical stuff is unobtainable.
> Specially the transformers and variable caps. A kit solves all that.,
> but there are no more kits like that one.

I built a FM tuner from a kit. I think it was Allied but for some reason 
Lafayette keeps nagging at me. I still have some air variables and ferrite 
torids for coils but they were getting difficult to find. Some of the caps 
came from the radios in junked cars I found in the desert. Nothing in the 
desert goes away although cars tend to get shot up. 

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#72002

On Fri, 22 Aug 2025 20:00:02 +0100, The Natural Philosopher wrote:

> On 22/08/2025 19:37, Carlos E.R. wrote:
>> On 2025-08-22 20:14, The Natural Philosopher wrote:
>>> On 22/08/2025 14:41, c186282 wrote:
>>>>
>>>>> I got this one when I went to uni:
>>>>>
>>>>> <https://www.etsy.com/es/listing/1791229461/vintage-sanyo-
transistor-
>>>>> radio-amfm>
>>>>
>>>>    I remember those !  🙂
>>>>
>>>>    Alas most of those little old radios had rather poor sensitivity
>>>>    plus poor selectivity.
>>>>
>>> Actually selectivity came easy as adding transistors was way cheaper
>>> than adding valves.
>> 
>> It came from adding intermediate frequency transformer stages, which
>> were not cheap nor easy to adjust.
> 
> They were cheap and they were *really* easy to adjust.
> 
> I build several portable radios.

I spend one winter sort of working my way through radio design history. 
Ever build a regenerative receiver? They're fun. 

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#72023

On 23/08/2025 07:00, rbowman wrote:
> On Fri, 22 Aug 2025 20:00:02 +0100, The Natural Philosopher wrote:
> 
>> On 22/08/2025 19:37, Carlos E.R. wrote:
>>> On 2025-08-22 20:14, The Natural Philosopher wrote:
>>>> On 22/08/2025 14:41, c186282 wrote:
>>>>>
>>>>>> I got this one when I went to uni:
>>>>>>
>>>>>> <https://www.etsy.com/es/listing/1791229461/vintage-sanyo-
> transistor-
>>>>>> radio-amfm>
>>>>>
>>>>>     I remember those !  🙂
>>>>>
>>>>>     Alas most of those little old radios had rather poor sensitivity
>>>>>     plus poor selectivity.
>>>>>
>>>> Actually selectivity came easy as adding transistors was way cheaper
>>>> than adding valves.
>>>
>>> It came from adding intermediate frequency transformer stages, which
>>> were not cheap nor easy to adjust.
>>
>> They were cheap and they were *really* easy to adjust.
>>
>> I build several portable radios.
> 
> I spend one winter sort of working my way through radio design history.
> Ever build a regenerative receiver? They're fun.
> 
I built several super-regenerative receivers for my model planes. 4 
transistor

With a high impedance earpiece you could pick up 'Voice of America' .

They where fun, Absolutely no selectivity,. I build a thoroughly illegal 
5W transmitter and was once able to recover a kids plane that had flown 
out of range
"What channel are you on, mister"

"Doesn't matter son".

Sigh, 27Mhz. Cowboy country




-- 
I was brought up to believe that you should never give offence if you 
can avoid it; the new culture tells us you should always take offence if 
you can. There are now experts in the art of taking offence, indeed 
whole academic subjects, such as 'gender studies', devoted to it.

Sir Roger Scruton

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#72078

On Sat, 23 Aug 2025 11:15:10 +0100, The Natural Philosopher wrote:

> I built several super-regenerative receivers for my model planes. 4
> transistor

Overkill. Armstrong's first attempt only needed one. He and De Forest 
fought over the patent. I think De Forest won the legal battle and lost 
the war.

The regens weren't very neighborhood friendly. 

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#72128

On 23/08/2025 22:32, rbowman wrote:
> On Sat, 23 Aug 2025 11:15:10 +0100, The Natural Philosopher wrote:
> 
>> I built several super-regenerative receivers for my model planes. 4
>> transistor
> 
> Overkill. Armstrong's first attempt only needed one. He and De Forest
> fought over the patent. I think De Forest won the legal battle and lost
> the war.
> 
> The regens weren't very neighborhood friendly.
Nope. They were not

-- 
“It is not the truth of Marxism that explains the willingness of 
intellectuals to believe it, but the power that it confers on 
intellectuals, in their attempts to control the world. And since...it is 
futile to reason someone out of a thing that he was not reasoned into, 
we can conclude that Marxism owes its remarkable power to survive every 
criticism to the fact that it is not a truth-directed but a 
power-directed system of thought.”
Sir Roger Scruton

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#72132

On 8/24/25 5:44 AM, The Natural Philosopher wrote:
> On 23/08/2025 22:32, rbowman wrote:
>> On Sat, 23 Aug 2025 11:15:10 +0100, The Natural Philosopher wrote:
>>
>>> I built several super-regenerative receivers for my model planes. 4
>>> transistor
>>
>> Overkill. Armstrong's first attempt only needed one. He and De Forest
>> fought over the patent. I think De Forest won the legal battle and lost
>> the war.
>>
>> The regens weren't very neighborhood friendly.

> Nope. They were not

   Well ........ depends on defs  :-)

   Super-Regen was a useful tech at the time.
   LOTS made.

   But the howl .......

   HellRaiser-II ... the future PinHead listens
   to a super-regen radio while fiddling with
   The Box :-)

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#72052

On 2025-08-23, rbowman <bowman@montana.com> wrote:

> I spend one winter sort of working my way through radio design history. 
> Ever build a regenerative receiver? They're fun. 

I started by building a crystal radio (using a germanium diode
rather than a cat's whisker).  A local radio station came in
just fine on the telephone handset I was using in lieu of
headphones - and then another nearby station cranked its
power up to 50 kW and smeared itself right across the dial.
No selectivity.

The next step was to add a tube amplifier, and after that
I threw on another coil and made it regenerative.  I can
still remember that ragged squeal it made when it went
into oscillation.

-- 
/~\  Charlie Gibbs                  |  Growth for the sake of
\ /  <cgibbs@kltpzyxm.invalid>      |  growth is the ideology
 X   I'm really at ac.dekanfrus     |  of the cancer cell.
/ \  if you read it the right way.  |    -- Edward Abbey

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#72079

On Sat, 23 Aug 2025 18:02:30 GMT, Charlie Gibbs wrote:

> The next step was to add a tube amplifier, and after that I threw on
> another coil and made it regenerative.  I can still remember that ragged
> squeal it made when it went into oscillation.

Everybody in the neighborhood probably remembered it too. What the holy 
hell is that kid up to now?

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#72098

On 2025-08-23, rbowman <bowman@montana.com> wrote:

> On Sat, 23 Aug 2025 18:02:30 GMT, Charlie Gibbs wrote:
>
>> The next step was to add a tube amplifier, and after that I threw on
>> another coil and made it regenerative.  I can still remember that ragged
>> squeal it made when it went into oscillation.
>
> Everybody in the neighborhood probably remembered it too. What the holy 
> hell is that kid up to now?

The horizontal output stage of our TV wiped out the short wave band
all the way up to 15 MHz, so I figured turnabout was fair play.

-- 
/~\  Charlie Gibbs                  |  Growth for the sake of
\ /  <cgibbs@kltpzyxm.invalid>      |  growth is the ideology
 X   I'm really at ac.dekanfrus     |  of the cancer cell.
/ \  if you read it the right way.  |    -- Edward Abbey

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#72094

On Sat, 23 Aug 2025 18:02:30 GMT, Charlie Gibbs wrote:

> ... and then another nearby station cranked its power up to 50 kW
> and smeared itself right across the dial. No selectivity.

My first visit to Wellington after leaving Uni, my little Sangean had that 
trouble, right across the FM band. That was the first time I found a use 
for the “RF gain” knob, at any setting less than full. Can’t remember what 
I set it to -- might have been something as low as 20%. At that point, I 
could tune in a range of stations just fine.

My friend who lived there said that was what happened in such a hilly 
city: all the stations cranked their power right up to try to ensure their 
listeners could find them.

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#72124

On 8/23/25 2:02 PM, Charlie Gibbs wrote:
> On 2025-08-23, rbowman <bowman@montana.com> wrote:
> 
>> I spend one winter sort of working my way through radio design history.
>> Ever build a regenerative receiver? They're fun.
> 
> I started by building a crystal radio (using a germanium diode
> rather than a cat's whisker).  A local radio station came in
> just fine on the telephone handset I was using in lieu of
> headphones - and then another nearby station cranked its
> power up to 50 kW and smeared itself right across the dial.
> No selectivity.
> 
> The next step was to add a tube amplifier, and after that
> I threw on another coil and made it regenerative.  I can
> still remember that ragged squeal it made when it went
> into oscillation.

   Yea, they DO squeal !!!

   But still, an interesting exercise
   in feedback and what you can do
   with it.

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#71977

On 8/22/25 2:37 PM, Carlos E.R. wrote:
> On 2025-08-22 20:14, The Natural Philosopher wrote:
>> On 22/08/2025 14:41, c186282 wrote:
>>>
>>>> I got this one when I went to uni:
>>>>
>>>> <https://www.etsy.com/es/listing/1791229461/vintage-sanyo-transistor- radio-amfm> 
>>>
>>>
>>>    I remember those !  🙂
>>>
>>>    Alas most of those little old radios had rather
>>>    poor sensitivity plus poor selectivity.
>>>
>> Actually selectivity came easy as adding transistors was way cheaper 
>> than adding valves.
> 
> It came from adding intermediate frequency transformer stages, which 
> were not cheap nor easy to adjust.

   Yep, not the transistors (previously valves), themselves
   but better-designed supporting circuitry and layout.

   You CAN make a very good AM radio with just four or
   five transistors - but if the feeds/couplings/resonators
   are pure cheap crap, well .......

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#72022

On 23/08/2025 04:06, c186282 wrote:
> On 8/22/25 2:37 PM, Carlos E.R. wrote:
>> On 2025-08-22 20:14, The Natural Philosopher wrote:
>>> On 22/08/2025 14:41, c186282 wrote:
>>>>
>>>>> I got this one when I went to uni:
>>>>>
>>>>> <https://www.etsy.com/es/listing/1791229461/vintage-sanyo-transistor- radio-amfm> 
>>>>
>>>>
>>>>    I remember those !  🙂
>>>>
>>>>    Alas most of those little old radios had rather
>>>>    poor sensitivity plus poor selectivity.
>>>>
>>> Actually selectivity came easy as adding transistors was way cheaper 
>>> than adding valves.
>>
>> It came from adding intermediate frequency transformer stages, which 
>> were not cheap nor easy to adjust.
> 
>    Yep, not the transistors (previously valves), themselves
>    but better-designed supporting circuitry and layout.
> 
>    You CAN make a very good AM radio with just four or
>    five transistors - but if the feeds/couplings/resonators
>    are pure cheap crap, well .......

Three IF stages is more than enough.

Feed the RF into a self oscillating mixer, that's the first transistor, 
and pull the IF off with the first IF can...

Then two more IF cans and transistors, so we are up to three, before a 
diode detector.

After that an audio stage driving a phase splitter transformer and two 
power outputs driving the final speaker impedance matching transformer.

6 transistors,

That is all you need for best audio quality. Better sets had an RF 
amplifier at the front so 7 transistors.



-- 
To ban Christmas, simply give turkeys the vote.

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#72113

On 8/23/25 6:11 AM, The Natural Philosopher wrote:
> On 23/08/2025 04:06, c186282 wrote:
>> On 8/22/25 2:37 PM, Carlos E.R. wrote:
>>> On 2025-08-22 20:14, The Natural Philosopher wrote:
>>>> On 22/08/2025 14:41, c186282 wrote:
>>>>>
>>>>>> I got this one when I went to uni:
>>>>>>
>>>>>> <https://www.etsy.com/es/listing/1791229461/vintage-sanyo-transistor- 
>>>>>> radio-amfm> 
>>>>>
>>>>>
>>>>>    I remember those !  🙂
>>>>>
>>>>>    Alas most of those little old radios had rather
>>>>>    poor sensitivity plus poor selectivity.
>>>>>
>>>> Actually selectivity came easy as adding transistors was way cheaper 
>>>> than adding valves.
>>>
>>> It came from adding intermediate frequency transformer stages, which 
>>> were not cheap nor easy to adjust.
>>
>>    Yep, not the transistors (previously valves), themselves
>>    but better-designed supporting circuitry and layout.
>>
>>    You CAN make a very good AM radio with just four or
>>    five transistors - but if the feeds/couplings/resonators
>>    are pure cheap crap, well .......
> 
> Three IF stages is more than enough.

   Agreed. You SHOULD be able to Do It in two.

> Feed the RF into a self oscillating mixer, that's the first transistor, 
> and pull the IF off with the first IF can...
> 
> Then two more IF cans and transistors, so we are up to three, before a 
> diode detector.
> 
> After that an audio stage driving a phase splitter transformer and two 
> power outputs driving the final speaker impedance matching transformer.
> 
> 6 transistors,
> 
> That is all you need for best audio quality. Better sets had an RF 
> amplifier at the front so 7 transistors.

   Well, truth, we're WAY past that kind of engineering.

   PLLs and friends ... SO much of the old engineering
   has become obsolete. Not really a Good Thing, but
   CHEAP ... that's how it is.

   "Broadcast" ... even that's Old Tech now. Net streams
   are the New Standard for "stuff".

   All the Old Knowledge ... DO try to preserve it for
   awhile. Post nukewar or asteroid or X11 solar flare
   ... that's what will be needed.

   Got a 1950s shortwave outfit, you MAY become a
   Most Important Person.

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#71976

On 8/22/25 2:14 PM, The Natural Philosopher wrote:
> On 22/08/2025 14:41, c186282 wrote:
>>
>>> I got this one when I went to uni:
>>>
>>> <https://www.etsy.com/es/listing/1791229461/vintage-sanyo-transistor-radio-amfm> 
>>
>>
>>    I remember those !  🙂
>>
>>    Alas most of those little old radios had rather
>>    poor sensitivity plus poor selectivity.
>>
> Actually selectivity came easy as adding transistors was way cheaper 
> than adding valves.
> And sensitivity soon got down towards the thermal noise

   Sure, LATER models. However the mid 50s units were
   not so great - BUT *portable* so ...

   So long as Frankie and Annette could play fake-rock
   down on the beach you had a winner  :-)

   You CAN get very good sensitivity/selectivity
   using valve units. Often it's less a matter of
   the valves but instead tighter 'Q' in the
   supporting circuits.

   As the price of transistors dropped, they became
   almost a sort of 'cheat' - a way to hide poor
   overall design. "Just slap another stage in there !"

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#72021

On 23/08/2025 04:01, c186282 wrote:
> On 8/22/25 2:14 PM, The Natural Philosopher wrote:
>> On 22/08/2025 14:41, c186282 wrote:
>>>
>>>> I got this one when I went to uni:
>>>>
>>>> <https://www.etsy.com/es/listing/1791229461/vintage-sanyo-transistor-radio-amfm> 
>>>
>>>
>>>    I remember those !  🙂
>>>
>>>    Alas most of those little old radios had rather
>>>    poor sensitivity plus poor selectivity.
>>>
>> Actually selectivity came easy as adding transistors was way cheaper 
>> than adding valves.
>> And sensitivity soon got down towards the thermal noise
> 
>    Sure, LATER models. However the mid 50s units were
>    not so great - BUT *portable* so ...
> 
>    So long as Frankie and Annette could play fake-rock
>    down on the beach you had a winner  :-)
> 
>    You CAN get very good sensitivity/selectivity
>    using valve units. Often it's less a matter of
>    the valves but instead tighter 'Q' in the
>    supporting circuits.
> 
Physically bigger coils. Point being that beyond a certain point you 
start to degrade the audio. For the sake of kicking out the adjacent channel

>    As the price of transistors dropped, they became
>    almost a sort of 'cheat' - a way to hide poor
>    overall design. "Just slap another stage in there !"

Many chinese style designs said '9 transistor' and when you looked at 
the circuit, 3 of them were duds, just soldered in the board but not 
connected to anything...

...Marketing. Imagine Intel marketing its latest chip 'over a billion 
transistors'

LOL
-- 
Renewable energy: Expensive solutions that don't work to a problem that 
doesn't exist instituted by self legalising protection rackets that 
don't protect,  masquerading as public servants who don't serve the public.

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#72026

On Sat, 23 Aug 2025 11:05:23 +0100, The Natural Philosopher wrote:

>> You CAN get very good sensitivity/selectivity using valve units.
>> Often it's less a matter of the valves but instead tighter 'Q' in
>> the supporting circuits.
>> 
> Physically bigger coils.

Or just a higher-order filter.

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#72086

On 2025-08-23 12:05, The Natural Philosopher wrote:
> Many chinese style designs said '9 transistor' and when you looked at 
> the circuit, 3 of them were duds, just soldered in the board but not 
> connected to anything...

Were they actual transistors, or also themselves duds? Transistors were 
not that cheap initially.

-- 
Cheers, Carlos.

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#72131

On 23/08/2025 23:27, Carlos E.R. wrote:
> On 2025-08-23 12:05, The Natural Philosopher wrote:
>> Many chinese style designs said '9 transistor' and when you looked at 
>> the circuit, 3 of them were duds, just soldered in the board but not 
>> connected to anything...
> 
> Were they actual transistors, or also themselves duds? Transistors were 
> not that cheap initially.
> 
Oh rejects.
The sort of thing Clive Sinclair used to badge as 'wonder components'

-- 
“It is dangerous to be right in matters on which the established 
authorities are wrong.”

― Voltaire, The Age of Louis XIV

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