Hi, I'm building a small valve communication receiver in an
effort to recapture some of the fun of my youth ))
And I am trying to find a circuit of a simple valve CW Audio filter
Years ago I built one from a circuit that was in the ARRL handbook
about 60's vintage, that was superb, anyone got an old Handbook
of that vintage that could have a look and possibly scan the
info, or possibly have a good one of their own using standard
valve componants!! long shot I know )
Thanks from Ron G3YUH

"Ron" wrote in message
...
Hi, I'm building a small valve communication receiver in an
effort to recapture some of the fun of my youth ))
And I am trying to find a circuit of a simple valve CW Audio filter
Years ago I built one from a circuit that was in the ARRL handbook
about 60's vintage, that was superb, anyone got an old Handbook
of that vintage that could have a look and possibly scan the
info, or possibly have a good one of their own using standard
valve componants!! long shot I know )
Thanks from Ron G3YUH


Do you recall if it was a twin-T filter? I might be able to find a tube
implementation. As I recall it took a twin
triode and used feedback.

Was your filter tunable?
N5EI

"Ron" wrote in message
...
Hi, I'm building a small valve communication receiver in an
effort to recapture some of the fun of my youth ))
And I am trying to find a circuit of a simple valve CW Audio filter
Years ago I built one from a circuit that was in the ARRL handbook
about 60's vintage, that was superb, anyone got an old Handbook
of that vintage that could have a look and possibly scan the
info, or possibly have a good one of their own using standard
valve componants!! long shot I know )
Thanks from Ron G3YUH


Do you recall if it was a twin-T filter? I might be able to find a tube
implementation. As I recall it took a twin
triode and used feedback.

Was your filter tunable?
N5EI

Hi, Well it was over 20yrs ago hi!! but I seem to remember
it was a twin triode setup
from Ron......


On Wed, 18 Feb 2004 06:57:27 -0500, "Edward A. Feustel"
wrote:


"Ron" wrote in message
...
Hi, I'm building a small valve communication receiver in an
effort to recapture some of the fun of my youth ))
And I am trying to find a circuit of a simple valve CW Audio filter
Years ago I built one from a circuit that was in the ARRL handbook
about 60's vintage, that was superb, anyone got an old Handbook
of that vintage that could have a look and possibly scan the
info, or possibly have a good one of their own using standard
valve componants!! long shot I know )
Thanks from Ron G3YUH


Do you recall if it was a twin-T filter? I might be able to find a tube
implementation. As I recall it took a twin
triode and used feedback.

Was your filter tunable?
N5EI

Hi, Well it was over 20yrs ago hi!! but I seem to remember
it was a twin triode setup
from Ron......


On Wed, 18 Feb 2004 06:57:27 -0500, "Edward A. Feustel"
wrote:


"Ron" wrote in message
...
Hi, I'm building a small valve communication receiver in an
effort to recapture some of the fun of my youth ))
And I am trying to find a circuit of a simple valve CW Audio filter
Years ago I built one from a circuit that was in the ARRL handbook
about 60's vintage, that was superb, anyone got an old Handbook
of that vintage that could have a look and possibly scan the
info, or possibly have a good one of their own using standard
valve componants!! long shot I know )
Thanks from Ron G3YUH


Do you recall if it was a twin-T filter? I might be able to find a tube
implementation. As I recall it took a twin
triode and used feedback.

Was your filter tunable?
N5EI

Hi,

That was perhaps the "Selectoject" which used a pair of
12AX7 (ECC83) valves in a phase-shifting audio peak or
notch filter. It was designed to go between the detector
and the first audio amp but could, I suppose, be used
equally well externally. If you will let me have an
address, I'll copy it for you from the 1956 Handbook or
from the appropriate QST CD.



73 de Joe, G3LLV

Hi,

That was perhaps the "Selectoject" which used a pair of
12AX7 (ECC83) valves in a phase-shifting audio peak or
notch filter. It was designed to go between the detector
and the first audio amp but could, I suppose, be used
equally well externally. If you will let me have an
address, I'll copy it for you from the 1956 Handbook or
from the appropriate QST CD.



73 de Joe, G3LLV

The 1967 ARRL handbook has one on page 148. It uses a 12AU7 and two 88 mH
toroids. Might that be what you were thinking of?
Bill N9BT

"Ron" wrote in message
...
Hi, I'm building a small valve communication receiver in an
effort to recapture some of the fun of my youth ))
And I am trying to find a circuit of a simple valve CW Audio filter
Years ago I built one from a circuit that was in the ARRL handbook
about 60's vintage, that was superb, anyone got an old Handbook
of that vintage that could have a look and possibly scan the
info, or possibly have a good one of their own using standard
valve componants!! long shot I know )
Thanks from Ron G3YUH

The 1967 ARRL handbook has one on page 148. It uses a 12AU7 and two 88 mH
toroids. Might that be what you were thinking of?
Bill N9BT

"Ron" wrote in message
...
Hi, I'm building a small valve communication receiver in an
effort to recapture some of the fun of my youth ))
And I am trying to find a circuit of a simple valve CW Audio filter
Years ago I built one from a circuit that was in the ARRL handbook
about 60's vintage, that was superb, anyone got an old Handbook
of that vintage that could have a look and possibly scan the
info, or possibly have a good one of their own using standard
valve componants!! long shot I know )
Thanks from Ron G3YUH

Hi Thanks everyone for the circuits
and info, I've just constructed the
modified Selectoject circuit and most
impressed!! I shall eventually try them
all, great fun, thanks
from Ron g3yuh..