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pinuccio48
Joined: 24 Jan 2002
Posts: 13
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 23 Feb 2002 1:36 |
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Is an helical filters design tool available?
Thanks
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niki
Joined: 20 Feb 2002
Posts: 11
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| 24 Feb 2002 13:25 |
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Difficult topic, needs a lot of experience.
One of the best information source:
Anatol I. Zverev, "Handbook of Filter
Synthesis", chapter 9: helical filters
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zerc
Joined: 22 Jul 2001
Posts: 16
Location: greece
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| 24 Feb 2002 13:43 |
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see also this link
http://www.waveconsoft.com/
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vanderspunk
Joined: 01 Jan 1970
Posts: 26
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| 24 Feb 2002 16:23 |
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Have not seen any really good program for helical filter design, but I can recommend the book Filters With Helical and Folded Helical Resonators by Peter Vizmuller, Artech House, ISBN 0890062447.
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Pim
Joined: 26 Jan 2002
Posts: 78
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| 24 Feb 2002 22:33 |
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I once managed to assemble a very high performance notch-filter for about 230 MHz by using a helix resonator with top-tuning (by adjusting the distance of a grounded plate closer or further from the top of the helix). I used it for a simple cable-tv descrambler as they just put on an interference signal on the RF for the channel.
I recall that I found some useful info regarding helix-based designs in the ARRL handbook (don't remember the year of the book, but it was at least 10 years old). The most work was not in calculating things but done by trial-and-error. I would strongly recommend a good book on the subject before trying anything like I did, i.e. trial-and-error as it was a very time-consuming task to get it all perfect.
Also, my design was sensitive for temperature (the dimensions of the helix, which was made of about 1,5 mm dia copper wire), changed sligthly with the temperature. So one had to fine-tune it now and then. But correctly tuned it had a superior performance indeed.
/Pim
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filterman
Joined: 18 Jan 2002
Posts: 52
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| 24 Feb 2002 23:32 |
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Hi
I am impressed the good advice elektoda member can provide.
I met once a Dos program for helical bandpass filter design,it was part if the old SCOPE suite(before it become serenade), it was part of the old RF design filters that accompanied supercompact and harmonica,maybe the present Ansoft team would be kind to give it to you for free as they didn't incorporate it in their new filter design tools.
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Rostfrei
Joined: 17 Sep 2001
Posts: 54
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| 17 May 2002 12:16 Help please |
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| Pim wrote: |
I once managed to assemble a very high performance notch-filter for about 230 MHz by using a helix resonator with top-tuning (by adjusting the distance of a grounded plate closer or further from the top of the helix). I used it for a simple cable-tv descrambler as they just put on an interference signal on the RF for the channel.
I recall that I found some useful info regarding helix-based designs in the ARRL handbook (don't remember the year of the book, but it was at least 10 years old). The most work was not in calculating things but done by trial-and-error. I would strongly recommend a good book on the subject before trying anything like I did, i.e. trial-and-error as it was a very time-consuming task to get it all perfect.
Also, my design was sensitive for temperature (the dimensions of the helix, which was made of about 1,5 mm dia copper wire), changed sligthly with the temperature. So one had to fine-tune it now and then. But correctly tuned it had a superior performance indeed.
/Pim |
Hello Pim 
I need to build notch filter with helical resonator for exactly the same thing as you deed. Can you please give me some guides on building it. Maybe you could send me your design so I could see how you did it ? I would need to build it for channel S9 (PAL) witch is on frequency 161.25 MHz.
Thanx in advance for all your help.
Regards,
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7rots51
Joined: 17 May 2002
Posts: 1298
Helped: 14
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| 08 Oct 2007 21:04 Re: Helical filters design |
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| any new info on helical filter design?pdf? article? soft?
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