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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets. |
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17th Aug 2008, 6:45 pm | #1 |
Tetrode
Join Date: Jun 2006
Location: Close to Luton Airport, Bedfordshire, UK.
Posts: 95
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Cathode Bypass Value
Hi
I am recapping a philips 206A set, the output valve (EBL31) cathode bypass in quoted as 25uF -25 volt, can i use 22uF or 33uF without problems. Barrie. |
17th Aug 2008, 6:47 pm | #2 |
Dekatron
Join Date: Sep 2003
Location: Bolton, Greater Manchester, UK.
Posts: 6,644
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Re: Cathode Bypass Value
Yes, you can. No worries!
Cheers, Steve P.
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17th Aug 2008, 6:50 pm | #3 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,967
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Re: Cathode Bypass Value
As Steve says, this is not a critical component. You can remove it altogether and the radio will still work and possibly sound better, though the gain will be reduced which may matter in a short superhet. Anything in the 22uF-100uF range will be fine.
Paul |
17th Aug 2008, 6:55 pm | #4 |
Dekatron
Join Date: Feb 2007
Location: Lynton, N. Devon, UK.
Posts: 7,088
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Re: Cathode Bypass Value
Yes, preferably the 33uF. Smaller values of cathode bypass capacitor will give you bass cut. Larger values will give you a level response down to a lower frequency. Of course, the bass roll-off is also governed by other factors, and in a good design it will be determined by components which are more predictable than the average electrolytic capacitor. That's why increasing the value should have no bad effect whatsoever.
Bear in mind the original Philips designers may have wanted a larger value in any case, and were constrained by cost to limit the value they specified to 25uF. |
17th Aug 2008, 10:18 pm | #5 |
Tetrode
Join Date: Jun 2006
Location: Close to Luton Airport, Bedfordshire, UK.
Posts: 95
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Re: Cathode Bypass Value
Many thanks for the replies,(sorted)
regards Barrie. |