In Reply to: RE: Any plans for alignment? (nt) posted by BFitz on August 15, 2011 at 19:00:50:
Thanks for sticking with me on this. My filter theory is very rusty.
I have two basic "questions"
1. Has it been established that the 10B IF section is indeed a series of cascaded, "non-resonant" bandpass filters providing an overall Butterworth response as the 10B promotional lit seems to imply? The schematic is drawn such that it looks like a series of buffered passive filters. Or is it just a fancy conventional resonant topology? Something else?
2. If this is indeed a series of cascaded bandpass filters, to achieve max flatness within the passband (as advertised) won't the individual filter pole frequencies and Qs be staggered in some manner to achieve the desired overall response characteristic. If this is the case, it's the frequency staggering of each section that I'd be trying to reverse engineer knowing that the overall filter characteristic was Butterworth of X order with a center frequency of 10.7 MHz and a bandwidth of say 200KHz. By knowing the frequencies for each section, one could then align each section individually to produce the desired overall response characteristic.
I don't own a network analyzer and if I did I wouldn't know how to use it in an FM IF alignment procedure. Is there info on this process? I'm not planning on getting an analyzer but I'm curious about the principles behind it.
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Topic - Progress on Marantz 10B restoration... - crooner 20:55:14 08/11/11 (26)
- Any plans for alignment? (nt) - Steve O 10:09:38 08/13/11 (12)
- RE: Any plans for alignment? (nt) - crooner 10:16:37 08/13/11 (11)
- RE: Any plans for alignment? (nt) - Steve O 10:22:37 08/14/11 (10)
- RE: Any plans for alignment? (nt) - BFitz 08:54:22 08/15/11 (5)
- RE: Any plans for alignment? (nt) - Steve O 15:59:36 08/15/11 (4)
- Supposedly... - crooner 10:57:16 08/14/11 (3)
- RE: Progress on Marantz 10B restoration... - BFitz 07:49:02 08/13/11 (1)
- RE: Progress on Marantz 10B restoration... - crooner 10:24:28 08/13/11 (0)
- RE: Progress on Marantz 10B restoration... - tesla 01:47:25 08/13/11 (2)
- Thank you. I thought that thing was chrome... - crooner 10:31:02 08/13/11 (1)
- RE: Thank you. I thought that thing was chrome... - fantja 05:17:25 08/14/11 (0)
- Re-stuffed filter capacitors... - crooner 06:04:10 08/12/11 (0)
- RE: Progress on Marantz 10B restoration... - geraldm121 05:59:21 08/12/11 (0)
- Bloody marvellous ............ - Timbo in Oz 21:53:41 08/11/11 (1)
- Thank you very much Sir! - crooner 22:08:09 08/11/11 (0)
- Before... - crooner 21:03:02 08/11/11 (0)
- And after.... - crooner 21:01:58 08/11/11 (2)
- The metal is a little pitted, but... - sherod 17:10:25 08/12/11 (1)
- Yes, but compared to the tons of rust that it had before... - crooner 17:30:45 08/12/11 (0)