XFILER box - xtal filters for use with Javornik on 14 MHz IF (S53WW, S51RM, S53RM)
With high number of high power stations and multiple antenna systems on top hill locations in 2m contests in Slovenia, wide band noise generated in transceivers becoming a problem. Reception of week signals is difficult. Almost all serious contestants in Slovenia use Javornik 144/14 transverters. Xtal oscillator in Javornik has very low phase noise compared to PLL oscillator in HF base stations, so 14 MHz pre-selector filtering reduce the problems on the band. More information and diagrams find on S53WW X FILTER box homepage.
Here is a diagram of IC-735 on SSB without filter, made with Perseus and HDSDR. Pretty narrow SSB signal with high noise level around:
And here with 14 MHz filter:
Next pictute is FT-1000MP with »not so nerrow SSB«, without filter:
And with filter:
Here is X FILTER box documentation (only in slovene language) in PDF format.
73 Sine - S53RM