Gendis Sony TR 7Z 7 transistor Radio.

radiotechnician · **Posted:** Mar Fri 16, 2012 7:50 am

Has anyone any information on this old Sony radio ? It seems to be the same as the TR 72.
Made by Tokyo Tsushin Kogyo Ltd . Is this Sony made before Sony Corporation was started?

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michaeljpro · **Posted:** Mar Fri 16, 2012 3:22 pm

Before January of 1958 SONY was the brand name used on electronic products produced by Tokyo Tsushin Kogyo.
After the success of their TR-63 pocket radio in the U.S. the company decided that changing the corporate
name to SONY would help in gaining acceptance world wide....it seemed to work

I have several TR-72 radios and all of them exhibit the same lettering which makes it appear like TR-7Z
but the radio you have is a TR-72.
The TR-72 was produced between 1956 - 1960, You have an early Tokyo Tsushin Kogyo version and judging
from the serial number yours may be from around late 1956. The early versions have the word TRANSISTORIZED
on the metal band that runs across the front/bottom and later models say SEVEN TRANSISTORS.

Here is a link to all the Sony radios in my collection including a few of the TR-72s. Lots more info there

http://www.flickr.com/photos/transistor ... 964396197/

rfenergy · **Posted:** Mar Fri 16, 2012 5:04 pm

michaeljpro wrote:

Before January of 1958 SONY was the brand name used on electronic products produced by Tokyo Tsushin Kogyo.
After the success of their TR-63 pocket radio in the U.S. the company decided that changing the corporate
name to SONY would help in gaining acceptance world wide....it seemed to work

I have several TR-72 radios and all of them exhibit the same lettering which makes it appear like TR-7Z
but the radio you have is a TR-72.
The TR-72 was produced between 1956 - 1960, You have an early Tokyo Tsushin Kogyo version and judging
from the serial number yours may be from around late 1956. The early versions have the word TRANSISTORIZED
on the metal band that runs across the front/bottom and later models say SEVEN TRANSISTORS.

Here is a link to all the Sony radios in my collection including a few of the TR-72s. Lots more info there

http://www.flickr.com/photos/transistor ... 964396197/

rfenergy · **Posted:** Mar Fri 16, 2012 5:06 pm

Michael email me as I have lost your address,I have some radios you may be interested in.
Jim

michaeljpro · **Posted:** Mar Fri 16, 2012 6:51 pm

Hi Jim, I think I have misplaced your email as well.
You can reach me at: michaeljpro at gmail dot com

Thanks!

radiotechnician · **Posted:** Mar Fri 16, 2012 7:42 pm

Thanks for the information. This TR-7Z does say transistorized on the bottom front metal strip. It does
not have the Sony badge in the upper left front, although there appears to a discoloration in the finish where
it might have been. Was that logo a small plate or just a decal? There is a indentation where a pin might have been
centered of the spot.

My set is in rough condition, finish wise. All electrical parts are there but the dust core of the second IF transformer is damaged.

The chassis construction is rather odd in that there are more support posts for a printed circuit than are
needed.

There are only 6 transistors, not 7, and two diodes. It has a 2 gang tuning capacitor.
The RF-IF circuit board looks like it was nibbled out on the edge adjacent the VC so
perhaps a 3 gang would fit.

Converter 2T73
First IF 2T76
Second IF grey flat Sony, no number seen.
PP Audio 2x2T84
Audio driver 2T66

I am wondering if there was a domestic, cheaper version made and a full 7 transistor version made
for export ?

Gendis Sony TR 7Z 7 transistor Radio.

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