Unfortunately, from fig 5 on page 6 of the TI datasheet, it has a roughly 2 volt dropout voltage across the LM338 when giving 1.5 amps. ?And you lose another 1.2 volts across that sense resistor. ? So the final would only get about 8.8 volts from a 12v battery. ? If you bump up that battery to 15 volts, then you get 11.8 volts into the final when transmitting at 7 watts, but the supply pops up to 15 volts when not speaking and current draw is low, likely blowing Q13 and the Q14 emitter resistor. ?The G0KLA circuit might be a better bet, it only drops out by around 0.6 or 0.7 volts. ?
On Thu, Feb 16, 2017 at 10:02 am, M Garza wrote:
Looking at the LM338, a 5 amp regulator, the app notes show a constant current regulator circuit.?
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