Talk:Regency TR-1

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A fact from this article was featured on Wikipedia's Main Page in the On this day section on October 18, 2012.

Germanium Transistors

Can anybody reading this shed light on why the TR-1 used germanium NPN transistors but a few years later virtually all germanium transistors were PNPs? BrianDGregory (talk) 14:02, 23 May 2010 (UTC)[reply]

That is an interesting question and 15 minutes of searching has not come up with an answer. I suspect it has something to do with grown junction transistors being replaced by alloy junction transistors - the Regency web site mentions in passing that the TI transistors were grown-junction type, which were expensive to produce. But i don't know enough about germanium transistor history to explain why the polarity switched. --Wtshymanski (talk) 15:04, 23 May 2010 (UTC)[reply]

And this [1] indicates the above is on the right track, thoguh not conclusive. --Wtshymanski (talk) 15:14, 23 May 2010 (UTC)[reply]

Thanks. You're a star. BrianDGregory (talk) 22:38, 27 May 2010 (UTC)[reply]

Hand-picked Transistors?

An article (http://www2.electronicproducts.com/What_s_It_Worth_Vintage_transistor_radios-article-fasj_worth_feb2012-html.aspx) says:

"Introduced in October of 1954, the Regency model TR-1 was the first widely marketed transistor radio. Developed by both Regency and Texas Instruments, the Regency TR-1 used four germanium transistors, which allowed the small 22.5-V battery to last for more than 20 hours. It differed from other prototypes in that due to its circuit design, hand selection of transistors for each individual radio was not necessary. This lead to higher production levels and lower production costs and made the price to the consumer affordable."

This contradicts the Wiki article.194.72.120.131 (talk) 08:32, 4 May 2012 (UTC)[reply]

Numbers

It would be interesting to add the total number produced, and when manufacture finished, if they are known.

Baska436 (talk) 23:30, 18 October 2012 (UTC)[reply]

 I was wondering the same thing myself.  — Preceding unsigned comment added by 98.82.127.122 (talk) 23:57, 18 October 2012 (UTC)[reply]

Schematic

I've not seen this on WP, but for a device this old (and with performance issues), why not show the entire circuit schematic? Is this still patented? Seems like somebody out there knows exactly how it was constructed. There are no integrated circuits at the time. so why not? --2600:6C48:7006:200:B056:6066:1296:EF0B (talk) 00:53, 18 October 2020 (UTC)[reply]

The schematic is there, which is from the patent. The service manual is on the http://regencytr1.com/ web site. Gah4 (talk) 03:51, 18 October 2020 (UTC)[reply]

Operation voltage

Why used this radio such a high voltage and why use later-built transistor radios lower voltage levels? — Preceding unsigned comment added by 2003:DF:1F1A:A715:537:139:56BA:95C3 (talk) 14:11, 18 October 2020 (UTC)[reply]

The info is in the article. The transistors had a poor frequency response. By operating them at a high voltage (near to the max voltage), the depletion layer is larger and hence the parasitic (Miller) capacitance is lower. This reduces the Miller feedback and gives a better frequency response. As the battery ran down, the depletion layer would shrink, the capacitance would rise and the radio would oscillate with the increased feedback. This occurred at around 15 volts. If it was not for this, the transistors would operate at lower voltages. The IF transistors had to have their Miller capacitance neutralised (the two capacitors at the top of the schematic marked as 100-200μμfd).

More modern radios use better transistors and thus can operate from much lower voltages. 86.164.169.96 (talk) 17:51, 18 October 2020 (UTC)[reply]