JJJelectronics- Low Pass Filter (LPF)

1 : LOW PASS FILTER 20 WATTS* 50R input and output impedance* Power rating 20w

Band 1: 160m Or Band 1: 80m Or Band 1: 40m Or Band 1: 20m/17m Or. Band 1: 15m/10m Or Band 1: 30m

Tool required.Soldering iron (25w-40w), small cutter

Now let’s build the LPF

When you have finished assembly of the board, check all the parts are in the right places.The soldering looks bright and good. Re-solder any suspect joints with a little fresh solder, check that there are no short or splashes of solder between tracks.

First wind the toroidsUse the table below for your band and wind the toroids with the right number of turnsuse thick wire (included), Passing the wire through the hole and then back out, counts as one turn

When you finished all toroids, solder them and solder the capacitos

band C2 C1/ middle C3 L1, L2 /turns160m 1.5nf 2.7nf 1.5nf 2780m 1nf 1.5nf 1nf 2140m 470pf 1nf 470pf 1520m/17m 180pf 330pf 180pf 1115m/10m 100pf 180pf 100pf 830m 330 560 330 14

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2 : LOW PASS FILTER 50 WATTS

* 50R input and output impedance* Power rating 50w * silver/ mica capacitors

Band 1: 80m Or Band 1: 40m Or Band 1: 30m Or Band 1: 20m/17m

Follow the same rule as 20w LPF

band C1 C2 C3 C4 C5 C6 L1/L280m 470pf ----- ----- 1nf 1nf 1nf 21T40m ---- 470pf 470pf ---- 1nf ----- 15T30m 330pf 330pf 330pf ---- 220pf ---- 14T20m 330pf 180pf 180pf ---- ----- ----- 11T