I am active as operator at the club station PI4Z and we wanted to take part as a multi single in the major HF contest of the year. To get a high score it is necessary to have a mulitplier station active on another band then the running station. To protect the receivers it is necessary to have good band pass filters.

I already have an ICE419B so I needed another filter. 

I started to look at options to purchase or build these.

I compared several commercial bandpass filters until I found that Bob 5B4AGN has made a design and has organized a group buy for a bandpass filter with builtin BCD band decoder and relay drivers.

The total price of €450 was low compared to the commercial available band passfilters, some of them costs twice that amount. I had to assemble myself of course but if you like building equipment this is an advantage.


The TXbpf like the ICE419 and the 5B4AGN TXBPF have a maximum power rating of 100W, they are used between the transceiver and the amplifier.

Link to the TXBPF groups.io site of Bob 5B4AGN.