Re: [softrock40] RXTX Q2 driver heatsink hot
- heat sink on a 2222, sounds over stressed.
Tony Parks <raparks@...> wrote:Hi Rick,The heatsink on the 2N2222A driver transistor runs pretty warm but so far that has not been a problem. The emitter voltage should be around 1.5 volts with no RF drive.I would recomend staying within the 1 watt RF output to be sure the output of the RXTXv6.1 is meeting FCC requirements.73,Tony KB9YIG----- Original Message -----From: Rick MeyerSent: Thursday, February 01, 2007 3:37 PMSubject: [softrock40] RXTX Q2 driver heatsink hotTony, the TX part of my new RXTX seems to be working with the IQ test
tones, but Q2, the TX driver transistor, has a heatsink that is
getting almost too hot to touch after a couple minutes at full power.
Is this normal? Should this part have a little bigger heatsink? What
should be the voltage at the emitter when there is no RF drive to mess
with my voltmeter?
Also I have the Ramsey 40 Meter power amplifier kit built and ready to
connect to the RXTX, but it will only put out half its rated 20 watts
of power with 1 watt drive from the RXTX. Can I feed the RXTX with
13.6 volts instead of 12 to get a little more power out of the Ramsey
PA? Would I need bigger heatsinks?