QRV since 1993.
Make the coil(s) per design. (see details filter/band)
Open the HP_BPF -tune sheet.
Check if the wire diameter, coil diameter, coil length and amount of turns match with your coil parameters. If not change the values.
Install the test C’s with a known value. Add the value to the sheet (Test C1a). Install correct C3abc with the C’s
Calculate the Fres with the OptiCoil program and add the value to the sheet.
Install the coil(s) on the PCB
On the bench, with the pcb outside the enclosure, measure the resonance frequency with a vna and tune the circuit as close as possible to Fres. Add the value “Measure outside”” to the sheet.
Put the PCB on its position in the enclosure, put the cover on the enclosure and measure the resonance frequency again. Add the value “Measure inside” to the sheet.
A calculated delta frequency with the pcb out and in the enclosure is displayed.
Take the PCB out. Retune the coil by compressing or stretching it to “Measure out site” – “Delta” = “Tune outside to” frequency.
Put the PCB in the enclosure again, close the cover and measure its resonance. The results must be within 1% of Fres. If not, repeat the above.
Remove the temporary test C .
Install the C’s or solder lubs per tabel