Friday, December 28, 2012

PA-47 at High Power !

The little Class "C" PA-47 RF Power Amplifier has grown up, I have doubled the original output of 4.7 Watts, to greater than 14 Watts.
PA-47 Ready for Modification
The new FET Leads will be bent
to Accommodate the Existing PCB Holes
I have replaced the general purpose IRF510 Power FET with an actual Special Purpose RD15HVF1 HF Power FET (from RFParts), and then connected the PA to a large stable DC Supply (Battery).

The results at full power, are;
  • With a 12.51 Volts DC supply running at 2050 ma (25.7 Watts DC Input with FAN)
  • Exciter provides 12 mWatts Input at 10.140MHz
  • The PA-47 output is 75 Volts PP RF measured at a 50 Ohm Load, which is: 14.1 Watts
  • The HeatSink Temperature at the FET raised about 20 degree to 94.7 Deg F
This is a gain of 30.70dB and a Efficiency of about 66%.

I am a real Happy Camper !

Note: this is a very small 1 x 1.5 inch PCB, with a large CPU HeatSink.

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I plan to re-layout the PCB to accommodate a Fan Control circuit and correct the small layout errors as explained on previous posts.


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1 comment:

  1. I'm noticing a pattern, I see a lot of cool homebrew projects that someone like myself would like to replicate, however you post no schematics. Please consider doing so in future postings. Thanks and 73, Jason W6IEE

    ReplyDelete