Part of a project on 1.2Ghz that will include this band-pass filter.

Main dimensions got online via the tool here: https://www.changpuak.ch/electronics/interdigital_bandpass_filter_designer.php

Some details of similar construction for different frequency range (ADS-B) here: https://keptenkurk.wordpress.com/2014/11/05/a-homebrew-1090mhz-ads-b-filter/

 

My construction:

 

Used FR4 double sided PCB for the sides and brass for elements, bottom and top

 

Online results example for dimensions:

 And the outcome:

 

Regarding results; not the best optimization for attenuation but not bad either considering the dimensions and construction not to the greatest dimensional andards:

Have a nice day!

 It is best to use the DRA818V VHF voice transceiver module with a low pass filter.

Since I'm building a VHF/UHF transceiver using the 818V and 818U modules, the VHF low pass filter was missing from the build.

 

This design was based from the one here and only some small values changes made , I placed adjustable cap's on the center elements (the 56pF), so used 10-60pF trimmer cap and used 32pF on the ends (10+22pF parallel). 

Schematic:

 After build did some measurement on the spectrum analyzer:

Final iteration of the trimmers:

 Attenuation at 200Mhz:

Filter shape from 100 to 300Mhz without normalization:

...now I need to finish the remaining of the transceiver..

 

Have a great day!