Author: N4GA – Rob
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Transmit Receive Sequencing your Amplifier
Last year I got a lot of pings asking “where you been… why no posts… did you quit…” etc. I get it! It’s been since May 24, 2020 since I last posted. Well, I’m not a retired ham – still putting two kids (both engineers) through college! Also, work has gotten extremely busy this past…
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The MRF1K50N
I was searching Mouser for a new LDMOS recently, as my trusty ole 1k80h finally went “out of round” on me. In the last few years, I’ve soldered and unsoldered this device four times and used it in countless amp designs. I’ve certainly TRIED to let the smoke out of it but it lives on.…
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LDMOS Amplifier Testing Setup
Here’s the testing setup. The enclosure is “universal” and different pallets get dropped into it. In the pic you can see the exciter (Flex 6300), spectrum analyzer, power supply, dummy load, RF power meter, ammeter and oscilloscope. Hiding in the back is a inline RF sampler. The way I test and develop these amps is…
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January 2019 LDMOS Amplifier
Here’s my latest dual 1K80H amplifier, mostly in pictures. Actually, this is not “my” design. I built this in an afternoon and it most resembles the Elecraft amplifier from the drains back (output section). The Elecraft output section design looked pretty elegant and simple. So I wanted to try and copy it and see how…
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Single versus Dual Bias for LDMOS RF Amps
Last year I decided I would design and build a regulated temperature-compensated independently adjustable dual bias circuit for my 2x LDMOS amp. (what a mouthful) Why? Because I wanted to try an experiment which actually works in a class AB audio amp. This being the ability to adjust the bias to affect the mix and…