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)

"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

"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

Thanks Harry!

Bookmarked :-)

--
Gregg
*It's probably useful, even if it can't be SPICE'd*
http://geek.scorpiorising.ca

Thanks Harry!

Bookmarked :-)

--
Gregg
*It's probably useful, even if it can't be SPICE'd*
http://geek.scorpiorising.ca

"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

"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

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

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