PA protection system
In order to provide a more clear overview on the protection system. You will find the blockdiagram below: It consists of the Power / SWR […]
100 – 1000 MHz
144 MHz Preamp using ATF54143
Preamp using the ATF54142 FET This design was made in 2006. It came back to my attention as my friend Jack PE1KXH asked for another […]
Broadband amplifier from 50 to 450 MHz
For my newly build 50-70 MHz amplifier I needed a suitable driver. I needed about 5W drive. I started with a CATV module, the BGY888. […]
Coaxrelay homemade out of cheap relays
The need for coaxrelays for the new 50-70 MHz amplifier led to this design. I had very good experiences with the Fujitsu relay which datasheet […]
AD8307 Frequency compensated
The AD8307 is a nice logarithmic amplifier with a lot of uses for amateur radio. My SWR Power meter is build around it. (LINK) The […]
144 MHz Bandpass filter revisited
144 MHz Bandpass filter revisited The 144 bandpass filter as shown on my website (here) has been a very popular article. It was the most […]
Wilkinson divider for 145 MHz
For operation on 2320MHz I needed a receive power splitter for my IF 144 MHz. It had to cover the 100-150 MHz range. The first […]
Using the specan as a dipmeter
Using the spectrum analyser as a dipmeter For a long time I never had the need to have a dipmeter for HF and VHF. This […]
PCB low pass filters
In a discussion I had with Peter, SM2CEW and Graham, F5VHX, the idea grew to make simple low pass filters. Simple but suitable for fairly […]
2 x GS35 PA for 144 MHz
Here follows a photo description of a 2 x GS35 PA for 144 MHz. Beware this is not a fully tested design! There are no […]