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dear friends,
I need that model for noise matching. To ask here for the model or subckt is my last possibility.
Perhaps s.o. has ...
thanx, best regards Leo
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Maybe this will help..
"Spice Models for Vacuum Tube Amplifiers" AES, March 1995
Cheers
A. Ganesan
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On 9/16/2011 7:24 PM, Charly Engineering wrote:
dear friends,
I need that model for noise matching. To ask here for the model or
subckt is my last possibility.
Perhaps s.o. has ...
thanx, best regards Leo
No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 9.0.914 / Virus Database: 271.1.1/3901 - Release Date: 09/16/11 13:34:00
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--- In LTspice@..., Ganesan <dg1@...> wrote:
Maybe this will help..
"Spice Models for Vacuum Tube Amplifiers" AES, March 1995
Cheers
A. Ganesan
Thanx, yes that helps, it's possible to enter the parameters from the data-book ... best regards, Leo
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--- In LTspice@..., Ganesan <dg1@...> wrote:
Maybe this will help..
"Spice Models for Vacuum Tube Amplifiers" AES, March 1995
Cheers
A. Ganesan
I could work out mu and k for that tube-model. Unfortunately I could not get any value for Rgk of the tube. :-( Rgk is a problem .... best regards Leo
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In message <j52p27+bpi2@...>, dated Sat, 17 Sep 2011, Charly Engineering <charly020664@...> writes: I could work out mu and k for that tube-model. Unfortunately I could not get any value for Rgk of the tube. :-(
Rgk is a problem .... Are you going to operate it with grid positive to cathode? If not, you don't need Rgk. If you are going to, you will need to find a characteristic for grid current versus positive grid voltage, or actually measure it. From that you can calculate Rgk. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK When I point to a star, please look at the star, not my finger. The star will be more interesting.
|
--- In LTspice@..., John Woodgate <jmw@...> wrote: Are you going to operate it with grid positive to cathode? If not, you
don't need Rgk. If you are going to, you will need to find a
characteristic for grid current versus positive grid voltage, or
actually measure it. From that you can calculate Rgk.
-- No, grid will not get positive to cathode. Can I delete Rgk from the subcircuit? best regards Leo ...
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Just make it 500 meg or something larger...
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On 9/17/2011 2:24 PM, Charly Engineering wrote:
--- In LTspice@... <mailto:LTspice%40yahoogroups.com>,
John Woodgate <jmw@...> wrote:
Are you going to operate it with grid positive to cathode? If not, you
don't need Rgk. If you are going to, you will need to find a
characteristic for grid current versus positive grid voltage, or
actually measure it. From that you can calculate Rgk.
-- No, grid will not get positive to cathode. Can I delete Rgk from the
subcircuit?
best regards Leo ...
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--- In LTspice@..., Ganesan <dg1@...> wrote:
Just make it 500 meg or something larger...
Thanx, I hope that will not be an adventuresome simulation :-) Leo
|
I remember you mentioned something about simulating noise.. You my have
to make rgk partially noise free..
(section 6 and section 7 give you a good idea of how to model noise}
Cheers
AG
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On 9/17/2011 2:32 PM, Charly Engineering wrote:
--- In LTspice@... <mailto:LTspice%40yahoogroups.com>,
Ganesan <dg1@...> wrote:
Just make it 500 meg or something larger...
Thanx, I hope that will not be an adventuresome simulation :-)
Leo
No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 9.0.914 / Virus Database: 271.1.1/3902 - Release Date: 09/17/11 01:38:00
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In message <j52s64+3f13@...>, dated Sat, 17 Sep 2011, Charly Engineering <charly020664@...> writes: No, grid will not get positive to cathode. Can I delete Rgk from the subcircuit? Yes, because there would be negligible current (maybe 100 nA) through it anyway. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK When I point to a star, please look at the star, not my finger. The star will be more interesting.
|
In message <4E74F464.5000207@...>, dated Sat, 17 Sep 2011, Ganesan <dg1@...> writes: Just make it 500 meg or something larger... Just omit it; why play with silly extreme values? -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK When I point to a star, please look at the star, not my finger. The star will be more interesting.
|
Leo,
a quick look at the datasheets shows that the 6R4 has similar mu to a 12AU7, twice the anode dissipation and approx half the anode resistance - the two halves of a 12AU7 in parallel, perhaps?
Might be a starting point, at least.
The Rydel_tubes.lib in the Files section of this group has a 12AU7 model.
Martin
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--- In LTspice@..., "Charly Engineering" <charly020664@...> wrote:
dear friends,
I need that model for noise matching. To ask here for the model or subckt is my last possibility.
Perhaps s.o. has ...
thanx, best regards Leo
|
I have added EC81 and 6R4 to the Koren_Tubes.cir library see the message
49829
Suusi Malcolm-Brown
|
Are vacuum tube symbols available to use in schematic capture.?
cheers
AG
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On 9/18/2011 4:59 AM, Suusi M-B wrote:
I have added EC81 and 6R4 to the Koren_Tubes.cir library see the message
49829
Suusi Malcolm-Brown
v
|
They are included in LTSPICE, just hit the insert component menu and
navigate to the "misc" folder...
.
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-----Original Message-----
From: LTspice@...
[mailto:LTspice@...] On Behalf Of Ganesan
Sent: 18 September 2011 11:35
To: LTspice@...
Subject: Re: [LTspice] Re: model, subckt tube EC81 = 6R4
Are vacuum tube symbols available to use in schematic capture.?
cheers
AG
On 9/18/2011 4:59 AM, Suusi M-B wrote:
I have added EC81 and 6R4 to the Koren_Tubes.cir library
see the message
49829
Suusi Malcolm-Brown
v
------------------------------------
Yahoo! Groups Links
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They look cool/ Thanks..
Cheers AG..
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On 9/18/2011 5:49 AM, Dave wrote:
They are included in LTSPICE, just hit the insert component menu and
navigate to the "misc" folder...
.
-----Original Message-----
From: LTspice@... <mailto:LTspice%40yahoogroups.com>
[mailto:LTspice@... <mailto:LTspice%40yahoogroups.com>] On Behalf Of Ganesan
Sent: 18 September 2011 11:35
To: LTspice@... <mailto:LTspice%40yahoogroups.com>
Subject: Re: [LTspice] Re: model, subckt tube EC81 = 6R4
Are vacuum tube symbols available to use in schematic capture.?
cheers
AG
|
Most vacuum tubes will work with ac or dc on their filaments ( some will
live a litle lesser under dc heating)... So the plate current is
proportional to the heat generated in the filament until maximum
emission is reached..( this is where most people use it).. Lifetime can
be improved at lower levels of heating , albeit with some loss of gain..
My question is, Whether the plate current to heater coupling is
correctly modeled through an rms function ?
Cheers
AG
toggle quoted message
Show quoted text
On 9/18/2011 5:49 AM, Dave wrote:
They are included in LTSPICE, just hit the insert component menu and
navigate to the "misc" folder...
.
-----Original Message-----
From: LTspice@... <mailto:LTspice%40yahoogroups.com>
[mailto:LTspice@... <mailto:LTspice%40yahoogroups.com>] On Behalf Of Ganesan
Sent: 18 September 2011 11:35
To: LTspice@... <mailto:LTspice%40yahoogroups.com>
Subject: Re: [LTspice] Re: model, subckt tube EC81 = 6R4
Are vacuum tube symbols available to use in schematic capture.?
cheers
AG
|
Thanks,,
cheers
AG
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Show quoted text
On 9/18/2011 5:49 AM, Dave wrote:
They are included in LTSPICE, just hit the insert component menu and
navigate to the "misc" folder...
.
-----Original Message-----
From: LTspice@... <mailto:LTspice%40yahoogroups.com>
[mailto:LTspice@... <mailto:LTspice%40yahoogroups.com>] On Behalf Of Ganesan
Sent: 18 September 2011 11:35
To: LTspice@... <mailto:LTspice%40yahoogroups.com>
Subject: Re: [LTspice] Re: model, subckt tube EC81 = 6R4
Are vacuum tube symbols available to use in schematic capture.?
cheers
AG
On 9/18/2011 4:59 AM, Suusi M-B wrote:
I have added EC81 and 6R4 to the Koren_Tubes.cir library
see the message
49829
Suusi Malcolm-Brown
|
In the real world there is quite a difference between individual valves of
the same type
The model that I created was derived from the Phillips / mullard 1968 book
graphs. There is no provision for varying the heater voltage. The heater is
assumed to be 6.3 volts DC or 6.3 volts AC (rms) No model is perfect, just
an approximation that is good enough.
The model was derived from the plate current vcs plate voltage graph for
different grid voltages. Using the below data points. The data points are
loaded into a matlab solver and the model generated.
Vplate = [ 50 50 50 50 50 100 100 100 100 100 100
150 150 150 150 150 200 200 200 200 200 200 250 250 250
250 250 300 300 300 300 300 300 300 300 ];
Vgrid = [ 6 4 2 0 -2 4 2 0 -2 -4 -6
0 -2 -4 -6 -8 -2 -4 -6 -8 -10 -12 -6 -8 -10
-12 -14 -8 -10 -12 -14 -16 -18 -20 -22 ];
Iplate = [ .0345 .026 .0185 .010 .004 .044 .035 .024 .015 .0073 .0025
.0415 .030 .020 .0118 .006 .048 .037 .026 .0175 .0105 .007 .043 .0325 .023
.0152 .0095 .050 .0388 .029 .021 .014 .009 .0055 .003 ];
Hope that answers your questions.
Suusi Malcolm-Brown
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-----Original Message----- From: LTspice@... [mailto:LTspice@...] On Behalf Of Ganesan Sent: 18 September 2011 12:25 To: LTspice@... Subject: Re: [LTspice] Re: model, subckt tube EC81 = 6R4 Most vacuum tubes will work with ac or dc on their filaments ( some will live a litle lesser under dc heating)... So the plate current is proportional to the heat generated in the filament until maximum emission is reached..( this is where most people use it).. Lifetime can be improved at lower levels of heating , albeit with some loss of gain.. My question is, Whether the plate current to heater coupling is correctly modeled through an rms function ? Cheers AG On 9/18/2011 5:49 AM, Dave wrote:
They are included in LTSPICE, just hit the insert component menu and
navigate to the "misc" folder...
.
-----Original Message-----
From: LTspice@... <mailto:LTspice%40yahoogroups.com>
[mailto:LTspice@... <mailto:LTspice%40yahoogroups.com>] On Behalf Of Ganesan
Sent: 18 September 2011 11:35
To: LTspice@... <mailto:LTspice%40yahoogroups.com>
Subject: Re: [LTspice] Re: model, subckt tube EC81 = 6R4
Are vacuum tube symbols available to use in schematic capture.?
cheers
AG
------------------------------------ Yahoo! Groups Links
|
Thanks.. i think some tubes used to carry plate current curves for different heater powers.. If going to 5.55 volts instead of 6.3 doubles the tube life, very few wouldn't do it..
cheers
AG
In the real world there is quite a difference between individual valves of
the same type
The model that I created was derived from the Phillips / mullard 1968 book
graphs. There is no provision for varying the heater voltage. The heater is
assumed to be 6.3 volts DC or 6.3 volts AC (rms) No model is perfect, just
an approximation that is good enough.
The model was derived from the plate current vcs plate voltage graph for
different grid voltages. Using the below data points. The data points are
loaded into a matlab solver and the model generated.
Vplate = [ 50 50 50 50 50 100 100 100 100 100 100
150 150 150 150 150 200 200 200 200 200 200 250 250 250
250 250 300 300 300 300 300 300 300 300 ];
Vgrid = [ 6 4 2 0 -2 4 2 0 -2 -4 -6
0 -2 -4 -6 -8 -2 -4 -6 -8 -10 -12 -6 -8 -10
-12 -14 -8 -10 -12 -14 -16 -18 -20 -22 ];
Iplate = [ .0345 .026 .0185 .010 .004 .044 .035 .024 .015 .0073 .0025
.0415 .030 .020 .0118 .006 .048 .037 .026 .0175 .0105 .007 .043 .0325 .023
.0152 .0095 .050 .0388 .029 .021 .014 .009 .0055 .003 ];
Hope that answers your questions.
Suusi Malcolm-Brown
|
Leo Baumann