Why 9-volt batteries?
Mike wrote:
In article ,
"Brenda Ann" wrote:
On Mon, 29 May 2006 12:42:56 -0400, Mike wrote:
In article a,
"jtaylor" wrote:
Why were they needed in the first place? The 9-volt package has a lot
more
package and a lot less mWatthrs in it. Was it because of the voltage -
did
the existing solid-state tech not work so well at 3V?
Probably. The very first transistor radios used a 45 volt battery!
MIke
Not exactly... some of the first radios with transistors in them (e.g. the
Emerson 838) used a 45 volt battery. But this battery was to supply the
plate B+ for the three peanut tubes in the RF/IF signal path. The transistor
audio outputs ran off the 4V "A" battery which also supplied the tube
heaters.
Actually, I was thinking of the first all-transistor radio -
specifically the Regency. But it uses a 22.5 bolt battery - my memory
was faulty.
IAC the point stands. Older transistor radios needed more volts
because of the low efficiency germanium transistors.
Mike
No, early germanium signal transistors didn't handle much current.
They were noisy, and had other problems that hadn't been ironed out
yet. They had a lot lower e-b voltage, and could be used at lower
voltages but it took a number of years to get the beta high enough to
make ones that had enough gain at a lower supply voltage.
--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.
Michael A. Terrell
Central Florida
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