EMRFD Message Archive 10964

Message Date From Subject
10964 2015-04-07 20:14:53 rcbuckiii Bandpass Filter Design
Does anyone know of an online calculator for Series-Trap, Shunt-C filter topology bandpass filters similar to this:




10965 2015-04-07 20:33:43 Cecil Bayona Re: Bandpass Filter Design
10966 2015-04-08 06:19:44 rcbuckiii Re: Bandpass Filter Design
I have Elsie and have ran the mesh capacitor coupled bandpass design tool. It produces some very odd values for the parallel tuned circuits. I tried modifying the L & C values but reasonable values destroy the passband shape.

I tried the same design in AADE program and it also produces very odd values for the parallel tuned circuits.

The PA3AKE filters are nice in that they do not use parallel tuned circuits which results in three less inductors. It may be better to just stick with the TTC design as shown in EMRFD even though those will have higher losses.

10968 2015-04-08 09:03:36 Steven B. Dick Re: Bandpass Filter Design
Try Elsie using a "mesh capacitively coupled bandpass" in the "Design" window.
Steve K1RF

10970 2015-04-08 10:16:26 farhanbox@gmail.c... Re: Bandpass Filter Design

i have found the combination of ladbuild and gpla found on the emrfd to be the easiest to use. they allow you to keep tweaking and experimenting. 

on the other hand, i wish i had picked up better skills at spice. most of our EDA software is a derivation of spice. 

as wes as often said : simulation is the greater experiment. these days i use the final sweep or scan to confirm the simulation. many a times, the simulation spurs you to build properly. i had simulated a 100mhz band pass filter on gpla. when i built it, the loss was almost 8db instead of the predicted 3 db. i was using thick silver wire and smt caps. i guessed that my construction was faulty. with more shielding between the coils and repeated scans, i finalled managed to hit the 3db point. simulation shows what is possible if you set it up properly (reasonabld Q etc.)

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10972 2015-04-09 09:44:24 p1jn3v11 Re: Bandpass Filter Design

I have a circuit board and all board parts for Hybrid Cascode AGC IF amplifier by W7ZOI .

$30 including shipping. PayPal

10975 2015-04-11 13:12:20 victorkoren Re: Bandpass Filter Design
It is designed by AADE filter design software (http://www.aade.com/filter32/download.htm).
You choose the Butterworth band pass filter with band pass Pi configuration and design it using 7th order filter and frequencies as needed. After designing the filter, you left button press each even dipole (on the result schematics) and choose replace dipole. Then you choose a capacitor in the dipoles table. Then you get the filter you asked for.
Victor - 4Z4ME