The Paesano Band Pass Filters

One of the major changes to the original project was to incorporate a Band Pass Filter that is connected to RLY1 so that it is used both on transmit and receive. On the front side of the BPF the signal routing is connected to output side of the 2N2219A Rx RF Amplifier. The same port on transmit is then connected to the input side of the Driver Stage (2N3904 & 2N5109) which is nothing more than a lift from EMRFD.

The original intent of The Paesano was use on 20 Meters --and that still is the plan. However for initial testing (given the sunspots) the BPF was set for 40 Meters. Some time ago I came up with a design for a BPF that with a simple change of two capacitors (150 PF) and some adjustment to five variable trimmer caps you have either 40 or 20 Meters. Makes things easy.

Alternatively the clever builder could come up with some sockets so that changing bands is merely a plug-in BPF filter. The same applies for the LPF.

Here is the detail in the event reading schematic is not your strong suit. The parts required are four each 0-50PF Trimmer caps, one 0-10 PF Trimmer cap, two 150 PF NPO (COG) fixed caps and two coils wound on T-68-2 (Red) cores. On 40 meters the two 150 PF caps are paralleled with two of the 50 PF trimmer caps and all trimmers are tuned for max smoke at 7.2 MHz. For 20 Meters, the two 150 PF are not connected (or installed) and all five trimmers are adjusted for max smoke at 14.2 MHz.