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#1
June 3rd 04, 09:45 PM
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Harry's Homebrew homepages.
http://w1.859.telia.com/~u85920178/
Over 200 projects, many with photo's and most with PCB patterns (BMP 250pixels/inch), even small PDF library and homebrew messageboard. Latest project is DIY IF cans for valves (tubes) complete with on-line calculators for the coils. Inc. Photographs. Would be interested to hear whether anyone has any suggestions for multi-gand tuning caps (100pf or more). I have been shoving tapered PCB strips between other and it works a treat, but there must be simpler methods. Also tried sponge/PCB sandwich with bolt compressor. Also works well, but capacity limited. Ideas anyone? (Not interested in varicaps/varactor diodes. They don't work so well with 250vDC!) BR Harry (E-mail, remove nospam and correct the spoelling error) |
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#2
June 3rd 04, 09:58 PM
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"Harry - SM0VPO" wrote in message
... http://w1.859.telia.com/~u85920178/ Over 200 projects, many with photo's and most with PCB patterns (BMP 250pixels/inch), even small PDF library and homebrew messageboard. Latest project is DIY IF cans for valves (tubes) complete with on-line calculators for the coils. Inc. Photographs. Would be interested to hear whether anyone has any suggestions for multi-gand tuning caps (100pf or more). I have been shoving tapered PCB strips between other and it works a treat, but there must be simpler methods. Also tried sponge/PCB sandwich with bolt compressor. Also works well, but capacity limited. Ideas anyone? (Not interested in varicaps/varactor diodes. They don't work so well with 250vDC!) It might be easier to vary the inductance. Permeability tuning is getting popular. 73, Leon |
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#3
June 3rd 04, 09:58 PM
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"Harry - SM0VPO" wrote in message
... http://w1.859.telia.com/~u85920178/ Over 200 projects, many with photo's and most with PCB patterns (BMP 250pixels/inch), even small PDF library and homebrew messageboard. Latest project is DIY IF cans for valves (tubes) complete with on-line calculators for the coils. Inc. Photographs. Would be interested to hear whether anyone has any suggestions for multi-gand tuning caps (100pf or more). I have been shoving tapered PCB strips between other and it works a treat, but there must be simpler methods. Also tried sponge/PCB sandwich with bolt compressor. Also works well, but capacity limited. Ideas anyone? (Not interested in varicaps/varactor diodes. They don't work so well with 250vDC!) It might be easier to vary the inductance. Permeability tuning is getting popular. 73, Leon |
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#4
June 3rd 04, 10:04 PM
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Thanks Harry!
Bookmarked :-) -- Gregg *It's probably useful, even if it can't be SPICE'd* http://geek.scorpiorising.ca |
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#5
June 3rd 04, 10:04 PM
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Thanks Harry!
Bookmarked :-) -- Gregg *It's probably useful, even if it can't be SPICE'd* http://geek.scorpiorising.ca |
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#6
June 3rd 04, 10:06 PM
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"Harry - SM0VPO" wrote in message
... http://w1.859.telia.com/~u85920178/ Over 200 projects, many with photo's and most with PCB patterns (BMP 250pixels/inch), even small PDF library and homebrew messageboard. Latest project is DIY IF cans for valves (tubes) complete with on-line calculators for the coils. Inc. Photographs. Would be interested to hear whether anyone has any suggestions for multi-gand tuning caps (100pf or more). I have been shoving tapered PCB strips between other and it works a treat, but there must be simpler methods. Also tried sponge/PCB sandwich with bolt compressor. Also works well, but capacity limited. Ideas anyone? (Not interested in varicaps/varactor diodes. They don't work so well with 250vDC!) Do you want a variable or a preset? If a preset, have you thought of using double sided PCB. One side un-etch, the other etched to give a series of lands that reduce in area. Connect more lands to increase capacitance. I saw the idea somewhere, so don't claim it as my own. -- 73 Brian G8OSN www.g8osn.org.uk www.amateurradiotraining.org.uk for FREE training material for all UK amateur radio licences www.phoenixradioclub.org.uk - a RADIO club specifically for those wishing to learn more about amateur radio |
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#7
June 3rd 04, 10:06 PM
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"Harry - SM0VPO" wrote in message
... http://w1.859.telia.com/~u85920178/ Over 200 projects, many with photo's and most with PCB patterns (BMP 250pixels/inch), even small PDF library and homebrew messageboard. Latest project is DIY IF cans for valves (tubes) complete with on-line calculators for the coils. Inc. Photographs. Would be interested to hear whether anyone has any suggestions for multi-gand tuning caps (100pf or more). I have been shoving tapered PCB strips between other and it works a treat, but there must be simpler methods. Also tried sponge/PCB sandwich with bolt compressor. Also works well, but capacity limited. Ideas anyone? (Not interested in varicaps/varactor diodes. They don't work so well with 250vDC!) Do you want a variable or a preset? If a preset, have you thought of using double sided PCB. One side un-etch, the other etched to give a series of lands that reduce in area. Connect more lands to increase capacitance. I saw the idea somewhere, so don't claim it as my own. -- 73 Brian G8OSN www.g8osn.org.uk www.amateurradiotraining.org.uk for FREE training material for all UK amateur radio licences www.phoenixradioclub.org.uk - a RADIO club specifically for those wishing to learn more about amateur radio |
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#8
June 4th 04, 09:49 AM
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Harry - SM0VPO wrote:
http://w1.859.telia.com/~u85920178/ Over 200 projects, many with photo's and most with PCB patterns (BMP 250pixels/inch), even small PDF library and homebrew messageboard. Latest project is DIY IF cans for valves (tubes) complete with on-line calculators for the coils. Inc. Photographs. Don't forget the non-electronics homebrew pages as well! Steve |
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#9
June 4th 04, 09:49 AM
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Harry - SM0VPO wrote:
http://w1.859.telia.com/~u85920178/ Over 200 projects, many with photo's and most with PCB patterns (BMP 250pixels/inch), even small PDF library and homebrew messageboard. Latest project is DIY IF cans for valves (tubes) complete with on-line calculators for the coils. Inc. Photographs. Don't forget the non-electronics homebrew pages as well! Steve |
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