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Title: Solid State Driver for dual 807 Amp Post by: N4LTA on March 07, 2012, 08:14:08 PM While waiting for some parts, I put together a PC Board to drive the dual 807 amp. The circuit may look familiar as I lifted most of it from the Retro 75 transmitter.
I needed a way to vary the output so I added a LM317 variable voltage regulator to the FET output device and it works great. I can vary the output from about 1/4 watt to 2.4 watts with 13.8 volts supplied to the board. I also changed the output filter a little. The board puts out a nice clean sine wave. The scope shows the output at 1 watt into a precision dummy load (couple of 2 watt 100 ohm resistors in parallel) I have run it at 1 watt for several hours with no problem. At 2.5 watts out, the heat sinks warm up pretty quickly, but I don't expect to need much more than 1 watt to drive the two 807s. Pat N4LTA (http://i620.photobucket.com/albums/tt286/n4lta/IMG_1153.jpg) (http://i620.photobucket.com/albums/tt286/n4lta/IMG_1154.jpg) Title: Re: Solid State Driver for dual 807 Amp Post by: W7TFO on March 07, 2012, 08:17:12 PM Looks good, it should hold up in a strong RF environment even if not totally shielded.
73DG Title: Re: Solid State Driver for dual 807 Amp Post by: N4LTA on March 07, 2012, 08:28:33 PM I plan to put it in a die cast aluminum box so it will be shielded. AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
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