If anyones got any experience replacing the original tubes on the tl922 for
a ceramic tube type
Ted, HI3TEJ
73
>From: amps-request@contesting.com
>Reply-To: amps@contesting.com
>To: amps@contesting.com
>Subject: Amps Digest, Vol 40, Issue 2
>Date: Sun, 02 Apr 2006 12:00:05 -0400
>
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>
>Today's Topics:
>
> 1. Re: tube impedance, figuring tank circuit values (TexasRF@aol.com)
> 2. Re: tube impedance, figuring tank circuit values (David C. Hallam)
> 3. Anyone familiar with Cubic 1500ZA? (john)
> 4. Re: Anyone familiar with Cubic 1500ZA? (Bert Almemo)
> 5. Metal Enclosures (w6ah@comcast.net)
> 6. TL922A (Dan Hearn)
> 7. Re: TL922A (Steve Thompson)
> 8. Re: TL922A (R@contesting.com)
> 9. Re: TL922A (Steve Thompson)
> 10. Re: TL922A (R@contesting.com)
>
>
>----------------------------------------------------------------------
>
>Message: 1
>Date: Sat, 1 Apr 2006 12:26:45 EST
>From: TexasRF@aol.com
>Subject: Re: [Amps] tube impedance, figuring tank circuit values
>To: g3rzp@g3rzp.wanadoo.co.uk, dezrat@copper.net,
> Chuck_Partain@maxtor.com, amps@contesting.com
>Message-ID: <23f.9b56cea.316011d5@aol.com>
>Content-Type: text/plain; charset="US-ASCII"
>
>
>Peter, I can't make this information agree with practice. For example, I
>have a TH347 amplifier on 23cm that runs 3000vdc at 1.8A on the plate.
>Conventional design would yield a plate impedance of 925 ohms using a k=1.8
> factor.
>This amplifier runs class AB2.
>
>With a screen voltage of 600v, the plate voltage swing is close to 2400v. I
>have read that peak plate current runs three times average typically or
>5.4A
>in this case. Using your information, this would yield a plate impedance of
>444 ohms.
>
>Clearly, some key factor is missing here. Perhaps my peak current equals
>three times average current factor is in error? Perhaps the plate voltage
>swing
>should include the "missing" half cycle?
>
>73,
>Gerald K5GW
>
>
>
>In a message dated 4/1/2006 5:04:08 A.M. Central Standard Time,
>g3rzp@g3rzp.wanadoo.co.uk writes:
>
>You have to figure on the supply volts under load.
>Let's assume we're in AB1 for an example. From the tube data sheet, we can
>choose the plate voltage when the grid volts are zero - usually just about
>the
>knee in the characteristics. That tells us that the load impedance is
>equal
>to the supply volts minus the knee volts divided by the plate current at
>Vg=0.
>Exactly the same principle applies if running AB2 or Class B, except you
>have to decide the positive grid volts that represents the peak of the
>cycle.
>Then you have the peak plate current, and the minimum plate volts. Again,
>the
>difference between the supply volts at that particular amount of current
>load
>and the minimum plate volts, divided by the peak plate current, gives you
>the
>load resistance.
>
>The factors relating the peak plate current, conduction angle and the DC
>drain on the PSU are more complex....
>73
>Peter G3RZP
>_______________________________________________
>Amps mailing list
>Amps@contesting.com
>http://lists.contesting.com/mailman/listinfo/amps
>
>
>
>
>
>
>------------------------------
>
>Message: 2
>Date: Sat, 1 Apr 2006 12:47:02 -0500
>From: "David C. Hallam" <dhallam@rapidsys.com>
>Subject: Re: [Amps] tube impedance, figuring tank circuit values
>To: <TexasRF@aol.com>, <g3rzp@g3rzp.wanadoo.co.uk>,
> <amps@contesting.com>
>Message-ID: <FAEILKLJLEEAGLJFOKEPAEEMCBAA.dhallam@rapidsys.com>
>Content-Type: text/plain; charset="us-ascii"
>
>I think that Peter inadvertently left out a factor of 2. According to my
>RCA tube manual Rp is equal to twice the plate voltage swing divided by the
>max current.
>
>David
>KC2JD
>
>-----Original Message-----
>From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com]On
>Behalf Of TexasRF@aol.com
>Sent: Saturday, April 01, 2006 12:27 PM
>To: g3rzp@g3rzp.wanadoo.co.uk; dezrat@copper.net;
>Chuck_Partain@maxtor.com; amps@contesting.com
>Subject: Re: [Amps] tube impedance, figuring tank circuit values
>
>
>
>Peter, I can't make this information agree with practice. For example, I
>have a TH347 amplifier on 23cm that runs 3000vdc at 1.8A on the plate.
>Conventional design would yield a plate impedance of 925 ohms using a k=1.8
>factor.
>This amplifier runs class AB2.
>
>With a screen voltage of 600v, the plate voltage swing is close to 2400v. I
>have read that peak plate current runs three times average typically or
>5.4A
>in this case. Using your information, this would yield a plate impedance of
>444 ohms.
>
>Clearly, some key factor is missing here. Perhaps my peak current equals
>three times average current factor is in error? Perhaps the plate voltage
>swing
>should include the "missing" half cycle?
>
>73,
>Gerald K5GW
>
>
>
>In a message dated 4/1/2006 5:04:08 A.M. Central Standard Time,
>g3rzp@g3rzp.wanadoo.co.uk writes:
>
>You have to figure on the supply volts under load.
>Let's assume we're in AB1 for an example. From the tube data sheet, we can
>choose the plate voltage when the grid volts are zero - usually just about
>the
>knee in the characteristics. That tells us that the load impedance is
>equal
>to the supply volts minus the knee volts divided by the plate current at
>Vg=0.
>Exactly the same principle applies if running AB2 or Class B, except you
>have to decide the positive grid volts that represents the peak of the
>cycle.
>Then you have the peak plate current, and the minimum plate volts. Again,
>the
>difference between the supply volts at that particular amount of current
>load
>and the minimum plate volts, divided by the peak plate current, gives you
>the
>load resistance.
>
>The factors relating the peak plate current, conduction angle and the DC
>drain on the PSU are more complex....
>73
>Peter G3RZP
>_______________________________________________
>Amps mailing list
>Amps@contesting.com
>http://lists.contesting.com/mailman/listinfo/amps
>
>
>
>
>_______________________________________________
>Amps mailing list
>Amps@contesting.com
>http://lists.contesting.com/mailman/listinfo/amps
>
>
>
>
>
>
>
>
>
>
>------------------------------
>
>Message: 3
>Date: Sat, 01 Apr 2006 15:36:53 -0500
>From: john <johnmb@nc.rr.com>
>Subject: [Amps] Anyone familiar with Cubic 1500ZA?
>To: amps@contesting.com
>Message-ID: <6.2.1.2.2.20060401153556.02492538@pop-server.nc.rr.com>
>Content-Type: text/plain; charset=us-ascii; format=flowed
>
>I have an option to get this, but have no idea of its technical info or
>appearance.
>Anyone know?
>
>Thanks
>John
>
>
>
>--
>No virus found in this outgoing message.
>Checked by AVG Free Edition.
>Version: 7.1.385 / Virus Database: 268.3.4/299 - Release Date: 3/31/2006
>
>
>
>------------------------------
>
>Message: 4
>Date: Sat, 1 Apr 2006 16:13:31 -0500
>From: "Bert Almemo" <balmemo@sympatico.ca>
>Subject: Re: [Amps] Anyone familiar with Cubic 1500ZA?
>To: "'john'" <johnmb@nc.rr.com>, <amps@contesting.com>
>Message-ID: <BAYC1-PASMTP05EA5F73C0BA9C312F3141D4D70@CEZ.ICE>
>Content-Type: text/plain; charset="US-ASCII"
>
>Hi John,
>
>Why not try eham.net There was one sold in 2002. Also see the product
>review. Good luck!
>
>73 Bert, VE3OBU
>
>
>
>-----Original Message-----
>From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] On
>Behalf Of john
>Sent: Saturday, April 01, 2006 3:37 PM
>To: amps@contesting.com
>Subject: [Amps] Anyone familiar with Cubic 1500ZA?
>
>I have an option to get this, but have no idea of its technical info or
>appearance.
>Anyone know?
>
>Thanks
>John
>
>
>
>--
>No virus found in this outgoing message.
>Checked by AVG Free Edition.
>Version: 7.1.385 / Virus Database: 268.3.4/299 - Release Date: 3/31/2006
>
>_______________________________________________
>Amps mailing list
>Amps@contesting.com
>http://lists.contesting.com/mailman/listinfo/amps
>
>
>
>------------------------------
>
>Message: 5
>Date: Sat, 01 Apr 2006 23:39:37 +0000
>From: w6ah@comcast.net
>Subject: [Amps] Metal Enclosures
>To: amps@contesting.com
>Message-ID:
>
> <040120062339.12354.442F0F39000CA8A4000030422209229927080EC099@comcast.net>
>
>Content-Type: text/plain
>
>A couple of years ago there was a thread about metal enclosures that
>included a link to a manufacturer in Northern California. As I recall they
>were located in Fremont. Does anyone have it handy ? Thanks for the time
>and attention
>
>Bob W6AH
>
>------------------------------
>
>Message: 6
>Date: Sat, 1 Apr 2006 15:50:30 -0800
>From: "Dan Hearn" <dhearn@wwnw.net>
>Subject: [Amps] TL922A
>To: "amps" <amps@contesting.com>
>Message-ID: <ACEGINBFNLHLHJAHIHCPGENDCLAA.dhearn@wwnw.net>
>Content-Type: text/plain; charset="iso-8859-1"
>
>I am trying to identify the resistor value and type used in the TL922A
>parasitic suppressors. I believe it is a 2W ohmite carbon but not sure and
>don't know the value. The schematic in the instruction manual does not give
>the value. I am aware of the problems of using carbon resistors in this
>application and the use of resistance wire suppressors with metal film
>resistors.
>Tnx, Dan, N5AR
>
>
>
>------------------------------
>
>Message: 7
>Date: Sun, 02 Apr 2006 10:18:55 +0100
>From: Steve Thompson <g8gsq@eltac.co.uk>
>Subject: Re: [Amps] TL922A
>To: amps@contesting.com
>Message-ID: <442F96FF.9020602@eltac.co.uk>
>Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
>
>
>Dan Hearn wrote:
> > I am trying to identify the resistor value and type used in the TL922A
> > parasitic suppressors. I believe it is a 2W ohmite carbon but not sure
>and
> > don't know the value. The schematic in the instruction manual does not
>give
> > the value. I am aware of the problems of using carbon resistors in this
> > application and the use of resistance wire suppressors with metal film
> > resistors.
>The one I have appears to be 2x47R in parallel.
>
>Steve
>
>
>------------------------------
>
>Message: 8
>Date: Sun, 2 Apr 2006 03:21:25 -0700
>From: R@contesting.com;Measures <r@somis.org>
>Subject: Re: [Amps] TL922A
>To: Steve Thompson <g8gsq@eltac.co.uk>
>Cc: amps@contesting.com
>Message-ID: <f34ff3d478f00c8341a475852d94f05f@somis.org>
>Content-Type: text/plain; charset=US-ASCII; format=flowed
>
>
>On Apr 2, 2006, at 1:18 AM, Steve Thompson wrote:
>
> >
> >
> > Dan Hearn wrote:
> >> I am trying to identify the resistor value and type used in the TL922A
> >> parasitic suppressors. I believe it is a 2W ohmite carbon but not
> >> sure and
> >> don't know the value. The schematic in the instruction manual does
> >> not give
> >> the value. I am aware of the problems of using carbon resistors in
> >> this
> >> application and the use of resistance wire suppressors with metal film
> >> resistors.
> > The one I have appears to be 2x47R in parallel.
>
>What is the measured R on yours, Steve?
> >
> > Steve
> > _______________________________________________
> > Amps mailing list
> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
> >
> >
>
>
>
>Rich Measures, 805.386.3734, AG6K, www.somis.org
>
>
>
>------------------------------
>
>Message: 9
>Date: Sun, 02 Apr 2006 11:35:21 +0100
>From: Steve Thompson <g8gsq@eltac.co.uk>
>Subject: Re: [Amps] TL922A
>To: amps@contesting.com
>Message-ID: <442FA8E9.2060301@eltac.co.uk>
>Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
>
>
>R; Measures wrote:
> >
> > On Apr 2, 2006, at 1:18 AM, Steve Thompson wrote:
> >
> >>
> >>
> >> Dan Hearn wrote:
> >>
> >>> I am trying to identify the resistor value and type used in the TL922A
> >>> parasitic suppressors. I believe it is a 2W ohmite carbon but not
> >>> sure and
> >>> don't know the value. The schematic in the instruction manual does
> >>> not give
> >>> the value. I am aware of the problems of using carbon resistors in
>this
> >>> application and the use of resistance wire suppressors with metal film
> >>> resistors.
> >>
> >> The one I have appears to be 2x47R in parallel.
> >
> >
> > What is the measured R on yours, Steve?
>24.9 ohms. It's the one you send me to characterise.
>
>Steve
>
>
>------------------------------
>
>Message: 10
>Date: Sun, 2 Apr 2006 03:41:29 -0700
>From: R@contesting.com;Measures <r@somis.org>
>Subject: Re: [Amps] TL922A
>To: Steve Thompson <g8gsq@eltac.co.uk>
>Cc: amps@contesting.com
>Message-ID: <c1478ea30d31347ba0b6315c8826f5a6@somis.org>
>Content-Type: text/plain; charset=US-ASCII; format=flowed
>
>
>On Apr 2, 2006, at 3:35 AM, Steve Thompson wrote:
>
> >
> >
> > R; Measures wrote:
> >>
> >> On Apr 2, 2006, at 1:18 AM, Steve Thompson wrote:
> >>
> >>>
> >>>
> >>> Dan Hearn wrote:
> >>>
> >>>> I am trying to identify the resistor value and type used in the
> >>>> TL922A
> >>>> parasitic suppressors. I believe it is a 2W ohmite carbon but not
> >>>> sure and
> >>>> don't know the value. The schematic in the instruction manual does
> >>>> not give
> >>>> the value. I am aware of the problems of using carbon resistors in
> >>>> this
> >>>> application and the use of resistance wire suppressors with metal
> >>>> film
> >>>> resistors.
> >>>
> >>> The one I have appears to be 2x47R in parallel.
> >>
> >>
> >> What is the measured R on yours, Steve?
> > 24.9 ohms. It's the one you sent me to characterise.
>
>Thanks. That one was virtually unused.
> >
> > Steve
> > _______________________________________________
> > Amps mailing list
> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
> >
> >
>
>
>
>Rich Measures, 805.386.3734, AG6K, www.somis.org
>
>
>
>------------------------------
>
>_______________________________________________
>Amps mailing list
>Amps@contesting.com
>http://lists.contesting.com/mailman/listinfo/amps
>
>
>End of Amps Digest, Vol 40, Issue 2
>***********************************
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