30 Aug
2008
30 Aug
'08
8:26 p.m.
On 30 Aug 2008 at 20:08, William Donzelli wrote:
No, they were quite known in the industry in the late
1940s.
Manufactures even had lines of subminiatures for the consumer market,
but they failed to make an impact - too expensive. The portables that
used them were out of reach for most pocketbooks, and frankly were not
all that much smaller than the portables that used regular minis.
The Hytron HY245/255 and Raytheon CK501, CK502... were known in 1939
or 1940. They were expressly targeted for hearing aid use pre-WWII.
The advent of subminiature tubes in hearing aids were very popular,
reducing something that was carried with a handle to something that
could be tucked into a shirt pocket. See, for example:
http://www.hearingaidmuseum.com/gallery/Vacuum%20Tube/index-
vacuumtube.htm
After the war, very small radios (e.g. Belmont Boulevard or the
Motorola Pixie) weren't uncommon. My first transistor radio was a 7
transistor Automatic that was larger than 2 Moto Pixies--metal hand-
wired chassis with transistors in sockets.
FWIW, minis (e.g. 9001, 9002) were available pre-war also.
Cheers,
Chuck