News:

Site maintenance in progress (expect intermittent wonkiness). Thanks for your patience!


DAN_000

Choosing constant reactance values for LC resonant filter
« on: March 01, 2009, 11:44:38 PM »
Like in Pultec or any other LC type filter, there are a constant value of reactance in the resonant frecuency.

Now the question :
If I choose a reactance value of 2500 and F=1KHz , how can I calculate gain(dB) and bandwidht of this filter at this frecuency ?

Thanks !


DAN_000

Re: Choosing constant reactance values for LC resonant filter
« Reply #1 on: March 02, 2009, 10:30:09 PM »
Bump!

CJ

Re: Choosing constant reactance values for LC resonant filter
« Reply #2 on: March 03, 2009, 01:58:13 AM »
Just compare the reactance with the other resistive elements that force the signal thru the filter.
If you have a 10K pot and a series reactance of 2500 and 2500, the you have a 5k to 10k ratio.

Bandwidth is just the series resistance of the inductor plus the resistor and or Q pot that is in the circuit.
If I can't fix it, I can fix it so nobody else can!
Frank's- www.mif.pg.gda.pl/homepages/frank/vs.html
Guitar- http://tdsl.duncanamps.com/schematics.php

DAN_000

Re: Choosing constant reactance values for LC resonant filter
« Reply #3 on: March 03, 2009, 10:51:08 PM »
OK, thanks CJ.   
I made my math with Pultec EQP-1A schemo and got around 10dB in filters. That's ok!.  In this case there is 3.333K to 10K ratio.

But, why around 2000 to 3000 of reactance in Pultec was choosed ? and not lower or higher value ?  ie: xl=25000+xc=25000  and 100K pot (10dB gain too)

Thanks!

CJ

Re: Choosing constant reactance values for LC resonant filter
« Reply #4 on: March 04, 2009, 12:11:44 AM »
This is where a simulator is a lot of fun.

Do you have one?
If I can't fix it, I can fix it so nobody else can!
Frank's- www.mif.pg.gda.pl/homepages/frank/vs.html
Guitar- http://tdsl.duncanamps.com/schematics.php

DAN_000

Re: Choosing constant reactance values for LC resonant filter
« Reply #5 on: March 04, 2009, 04:02:23 PM »
No, but I will donwload one simulator tonight and check this.
Thanks CJ !!



 

Related Topics

  Subject / Started by Replies Last post
2 Replies
1479 Views
Last post November 16, 2004, 11:20:32 PM
by ytrehalf
16 Replies
3307 Views
Last post July 05, 2005, 09:28:18 AM
by SSLtech
35 Replies
6668 Views
Last post November 08, 2007, 11:54:51 AM
by emrr
5 Replies
2210 Views
Last post December 16, 2010, 09:30:28 AM
by JohnRoberts
4 Replies
1055 Views
Last post September 11, 2012, 09:22:12 AM
by Dan Kennedy