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Title: My Super-JS 300 watt carrier output 40 meter rig - Clip leads abound! Post by: steve_qix on December 29, 2023, 06:13:18 PM I have been hearing that 40 meters has been good, so I got a 40 meter transmitter on the air. This RF amplifier is actually a prototype of a 6.78 mHz ISM band transmitter that I designed for a client.
This setup puts out 300 watts carrier when running 45V @ 7.5A. The rig is VERY efficient. This design uses 4 FQA11N90 MOSFETs, and each MOSFET has its own driver IC (IXDD614). 40 was REALLY good today - lots of activity, and strong signals. We were mostly on 7280. (http://www.classeradio.com/40_meter_class_e.jpg) Title: Re: My Super-JS 300 watt carrier output 40 meter rig - Clip leads abound! Post by: w9jsw on December 30, 2023, 08:30:24 AM Can you describe the schematic vs your posted 400W 80M example.
http://www.classeradio.com/8_fet.htm My guess is it is almost identical except dropping 4 of the mosfets to get a 1:1 driver to mosfet ratio? Anything else change? How agile is the design. Can the output be re-tuned to 80M or will that require some switching/relays to change key component values? Can this be built with readily available mosfets - say 16n50s or FQA13N80-F109? Title: Re: My Super-JS 300 watt carrier output 40 meter rig - Clip leads abound! Post by: wa1sth on January 02, 2024, 08:00:39 PM Now that is an inspiring piece of work. VERY colorful...Hope your pies look better
Title: Re: My Super-JS 300 watt carrier output 40 meter rig - Clip leads abound! Post by: WA2SQQ on January 03, 2024, 11:02:37 AM My guess is if he meeting things up, it probably would not work as well. It demonstrates the magic of all those clip leads!
Title: Re: My Super-JS 300 watt carrier output 40 meter rig - Clip leads abound! Post by: Opcom on January 05, 2024, 01:28:16 AM Showed that JS picture to a 'radio buff' friend of mine and he lost his mind!
me: Check out this 1000 watt ham radio transmitter! he: I don't see it. Yoiu sent a picture of parts on a desk. me: That's the transmitter. he: Naw, I know better than that. What are you trying to pull, man??!?? THIS is one reason I love electronics. Title: Re: My Super-JS 300 watt carrier output 40 meter rig - Clip leads abound! Post by: W3SLK on January 05, 2024, 10:03:53 AM I don't know if he was using this particular lash up when I talked to him on 40M yesterday, but it certainly put the sloppbucketeers at bay while he was transmitting. It definitely cut a nice hole in the aether!
Title: Re: My Super-JS 300 watt carrier output 40 meter rig - Clip leads abound! Post by: steve_qix on January 06, 2024, 01:35:30 AM Yes, that is the transmitter I was using :-) It is the only 40 Meter transmitter I have (well, I could put the Flex 5000 on the air, and run it into an SB-200 linear I have), but I haven't done that....
That little JS rig really works very well. It is AMAZINGLY efficient, and puts out a lot of power for 4 MOSFETs (315 watts carrier). Title: Re: My Super-JS 300 watt carrier output 40 meter rig - Clip leads abound! Post by: W3SLK on January 06, 2024, 10:11:21 AM Excellent Steve! Please have a safe trip down here to NEPA. Us along with State College is supposed to get dumped on! AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
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