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Old 6th Sep 2010, 10:47 am   #9
f.cooper
Retired Dormant Member
 
Join Date: Oct 2006
Location: Stoke-on-Trent, Staffordshire, UK.
Posts: 128
Default Re: Transistor Choice in radio project

Hi,
The OC71 had identical ratings in both the data books:-

hfe typ (Ic = 1mA, VCE - -2V ) 41

The OC71 was a first generation general purpose transistor for low power applications
( Pto max. 75mW ). It was generally OK for audio applications but no good for rf applications, OC45 (was used for IF frequencies ( 470 Kcs ) whereas the OC44 was used as a mixer ( frequency changer ). Most early transistors had limitations as to maximum useable frequency.

Figures quoted in most data books were generally the minimum or average values to expect.
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