I recently spotted the Tokmas CI7N170SM TO-247 part on LCSC. It seems like a pretty neat part for building non-QRP HF amplifiers! This could be a better part for our Baby QRO amplifier. Datasheet Excerpts The full datasheet is available here. Comparison In comparison, here is what a professional RF part (MRF300AN) looks like: That 272W maximum power dissipation figure is crazy good but switching characteristics are not that great (fast).
Circuit: DDX-Commercial-7 Antenna: Small jumper cable attached Initial Results 10m: 36 dB on WSJT-X audio meter, on quiet and also with nearby beacon on !!! 12m: 36 dB on audio meter, on quiet and also with nearby beacon on !!! 15m: 46 dB on audio meter on quiet, 65 dB with nearby beacon on - OK 20m: 44 dB on quiet, 65 dB with beacon on - OK 40m: 40 dB on quiet, 60 dB with beacon on - OK ...
Note: This HF LNA design is inspired by Charlie Morris ZL2CTM's prior work. Design The idea that a single-transistor preamp with 10 dB gain is more than enough for HF comes from Gajendra Kumar (VU2BGS). As a new "designer," I am often overwhelmed by the different possible design paths, so guidance from an elmer is crucial. It seems even MMBT2222A should work for building a HF LNA! ...
Ismo (OH2FTG) recently introduced me to a bunch of Tokmas RF parts. Out of these, the Tokmas CID10N65F GaN FET stood out. It seems to have a lot of potential (for HF + 6m) at a very low price point. This RF MOSFET part can be purchased from LCSC. It seems Tokmas CID10N65F has the potential to completely replace the RD16HHF1 part from Mitsubishi Electric! Datasheet Datasheet excerpt: ...
I have designed, built, and tested an all-HF WSPR beacon that produces 1W @ 5V and is rugged and cost-effective. Results Power consumption: Around 420mA @ 5V. Cost Cost: Around 500 INR. Time to build Time to build: Less than 30 minutes. Files The files for this project are published here for personal (non-commercial) use. For a 5W (QRO) WSPR beacon, please stay tuned for our upcoming QEX magazine article ;) ...
Sometimes we all need a bit of QRO - Life's too short for QRP sometimes. So we give you the Baby-QRO switching amplifier! This Baby-QRO switching RF amplifier design is inspired by the wonderful Single NXP MRF-101 Eval Board project by Jim Veatch. Thank you Jim! Instead of using the expensive MRF101 MOSFET, we use fast SiC MOSFET(s) from Wolfspeed / SUPSiC. Design 3D render: Actual picture: ...