Work has already begun on the final chapter of High Power HF Filter Design. A 40m bandpass filter has been designed, built, and tuned up as the major subject of Chapter 9. A second filter for 15m is in progress and once it is built, its design documentation will be updated and the book “go to press”.
A project to capture how to design and build KW filters for HF was begun in December 2021 with completion anticipated around late 2022/early 2023. The application of the governing equations is included and the Appendix gets into the mathematical details of their derivation. Two chapters outline the design and construction of a 40m and 15m bandpass filter. A large amount of detail on capacitors and toroids is included with a great emphasis on the use of Norton transformations.
After almost 15 years of flawless service, I have replaced the Tentec Centurion with an ACOM 2000A automatic tuning amplifier. I have been reluctant to make this change given the great tenure of the Tentec, however the rapid band changing ability will be great to have. I struggled between the ACOM and another Elecraft KPA1500 which is one great amplifier. I elected to go with the ACOM primarily for its much quieter operation, opting not to have two amplifiers with fans running to keep their heat sinks cool.
Sadly, I decided to replace my Alpha 8410 in January 2021. While it was a 9.9 on a 10 point scale and effortlessly put out 1.5 KW or more on all bands, I decided that a) instant QSY was important to me, and b) the cost of replacement tubes “someday” was too high for my comfort. The replacement is an Elecraft KPA1500 and although its use spans a mere 24 hours, “I love it”. Great engineering, feature comforts, and excellent performance, especially when married up with an Elecraft transceiver.
Mid-November 2020 completed the addition of three Caribbean-oriented yagis on the 90 foot tower. Through the use of remotely controlled 1 x 2 transfer switches, RF is instantly channeled to these SE pointing antennas when needed; no antenna rotation required. The yagis cover 10, 15, and 20m. They worked flawlessly in CQWW CW 2020. A writeup is included in both Scribbles and Power Point Presentations sections.
Unfortunately, my Orion II has developed several problems; the master TCXO wants to wander outside its calibration range and there have been several instances where intermittent issues have shown up in the baseband processors. I am going to miss this radio that has served me well for 12 years.
The new K3S is just an updated version of the K3 which is already present. Some differences in VFO phase noise, less distorted audio, etc. are in the new K3S design.