(between a reversed dioden mixer and a rellay "input of PA"(usually few Volts RF-TX) or "Antenna RX")

The main part of any RIG  wich hard to tuning at home without a special equipment .

Can be used as the additional band pass filter between antenna and a cheap receiver .

People say it pass perfect as PreSelector to PCR100, PCR1000 , SDR ...

                                                         Dimension is 185x75 mm.

 This unit tuned  for 160,80,40,30,20,17,15,12,10 m   amateurs   bands.

                                                                  Rin=Rout=50Ohm.

Losses are 1-3 dB. It has RF amplifier with frequency compensated gain(10-20dB), 

using one medium power RF transistor , and attenuator -20dB.

The operating voltage for instaled relays is  5V .(On the diagram in 5V variante BPF is also must be 5V everywhere - not 12-27!!!)

The typical picture from the screen is for 1,8:3,5:14:18 Mhz. 

Passband ripple is abt. 0.5dB inside the band .

The pictures for the other bands are similar - with passband ripple from 0.2 to 1 db typical .

I try to make M=1-2, in this case the best possible for 2 connected coils filters K01=abt.3 and K001=abt.8-10.

K001 is - 40 dB.For instance:Band 3.5 MHz.Band width = 0.3 MHz. With Koo1=8 (M2.41) width

 on the level -40 dB will be 2.4MHz.It means +1.2 and -1.2 from central 3.650.

Standart bandwidth  is( by level of 0.5-1 db):1,8-2,0:3,5-3,8:7,0-7,2:10,0-10,150:14,0-14,350:18,0-18,2:21,0-21,45:24,8-25,0:28,0-29,7.

By the level -40 dB it is good sample of calculation above in description.This is maximum what possible theoreticaly for 2 LC filters.

 Attenuation is approx. 2 dB - depending on band and bandwidth.

                                         ................................................

            To USA, Canada, UK, Japan, Australia - 10-14 days, 14-21 days to Germany/France.

 In the way to  Italy is always very different in time.

The very typical view (can be a different coils typе):