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Re: [Amps] IM Distortion

To: edk0kl@centurytel.net
Subject: Re: [Amps] IM Distortion
From: R L Measures <r@somis.org>
Date: Wed, 28 Jun 2006 07:47:13 -0700
List-post: <mailto:amps@contesting.com>
On Jun 28, 2006, at 5:16 AM, Edwin Karl wrote:

> Does the new graphite tubes change any of the dynamic of the
> discussion? i.e. 3-500Zg. It would appear the supposed extra
> 100 watts of plate dissipation

The dissipation ability of a graphite anode is not more than the  
dissipation ability of a similarly sized metal one.

> should enable you to "Pump up
> the Volume". Something that post dates the Eimac sheets  ...

To pump things up, one needs more peak emission or/and more HVDC.
>
> ed K0KL
>
>
>
> -----Original Message-----
> From: amps-bounces@contesting.com [mailto:amps- 
> bounces@contesting.com]On
> Behalf Of amps-request@contesting.com
> Sent: Tuesday, June 27, 2006 4:07 PM
> To: amps@contesting.com
> Subject: Amps Digest, Vol 42, Issue 75
>
>
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> Today's Topics:
>
>    1. Re: IM distortion and such (Will Matney)
>    2. Re: IM distortion and such (Will Matney)
>    3. Re: IM distortion and such (R L Measures)
>    4. Re: IM distortion and such (R L Measures)
>    5. Re: IM distortion and such (R L Measures)
>    6. WTB: Johnson SK-650 or Johnson 124-109-1 socket (wc6w@juno.com)
>    7. Re: IM distortion and such (Will Matney)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Tue, 27 Jun 2006 14:44:18 -0400
> From: "Will Matney" <craxd1@verizon.net>
> Subject: Re: [Amps] IM distortion and such
> To: amps@contesting.com
> Message-ID: <200606271444180130.07AE73EF@outgoing.verizon.net>
> Content-Type: text/plain; charset=us-ascii
>
> Tom,
>
> No, your not showing everything I said. It does in fact mention  
> "Two-Tone DC
> Plate Current 280 mA" It lists it in the same place with two different
> currents that would cause the same result (with single tone). That  
> would be
> the only reason to place both under the same title. Though this is  
> for class
> B, I said in a later e-mail that I know IMD would be better under  
> class AB
> or B. Actually the IMD shown drops 5 dB by dropping the plate  
> voltage and
> the plate current a small amount under another reference in the  
> spec sheet
> before this.
>
> For some odd reason, during the last 3-4 days, my mails to this  
> list are not
> posting as soon as I send them. It is like they are being delayed  
> by a few
> hours sometimes before they are posted. Some of these reference  
> mail I have
> sent but hasn't been posted yet.
>
> Again Quote;
>
> RF Linear Amplifier
> Grounded-Grid, Class B
>
> Maximum Ratings
>
> Typical operation (Minimum distortion products at 1 KW PEP input)**
> DC Plate Voltage 2500V
> Zero Signal DC Plate Current* 130 mA
> Single-Tone DC Plate Current 400 mA
> Single-Tone DC Grid Current 120 mA
> Two-Tone DC Plate Current 280 mA
> Two-Tone DC Grid Current 70 mA
> Peak Envelope Useful Output Power 600W
> Resonant Load Impedance 3450 Ohms
> Intermodulation Distortion Products -33 dB
>
> *Approximate Value
> ** Measured Data From A Single Tube
>
> End Quote
>
> Better IMD was obtained by lowering the plate voltage under "(Minimum
> Distortion Products)" at -38 dB, 500W, and at 2000 Vdc.
>
> Best,
>
> Will
>
>
> *********** REPLY SEPARATOR  ***********
>
> On 6/27/06 at 2:22 PM Tom W8JI wrote:
>
>>> Tom,
>>>
>>> It says it on page two of the Eimac 3-500Z spec sheet. See
>>> the one the link was provided for earlier.
>>
>> Single tone carrier level has absolutely nothing to do with
>> operation in a different set of conditions such as two-tone
>> modulation at a different anode voltage, bias, and power
>> level. You are reading more into the data sheet than it is
>> saying.
>>
>> For a given set of tuning conditions (load line) a person
>> can make the single tone level any level he wants by varying
>> drive and the two-tone test will remain the same as long as
>> the two-tone power level isn't changed. Single tone and
>> two-tone are two totally different conditions, and as the
>> data sheets say other operation is permissible.
>>
>> Two other random people besides myself have now posted that
>> the did the equivalent of a transfer function (which is what
>> really measures linearity) and both posted the best
>> linearity when the steady-state loadline was established at
>> about 550mA. Actual performance under one set of conditions
>> cannot be determined by extracting data from a test under
>> totally different conditions.
>>
>> 73 Tom
>>
>>
>> _______________________________________________
>> Amps mailing list
>> Amps@contesting.com
>> http://lists.contesting.com/mailman/listinfo/amps
>
>
>
>
>
> ------------------------------
>
> Message: 2
> Date: Tue, 27 Jun 2006 16:37:30 -0400
> From: "Will Matney" <craxd1@verizon.net>
> Subject: Re: [Amps] IM distortion and such
> To: r@somis.org, amps@contesting.com
> Message-ID: <200606271637300990.08161EA1@outgoing.verizon.net>
> Content-Type: text/plain; charset=us-ascii
>
> It's in the PDF file that was posted by someone earlier. There was  
> nothing
> in it though about class AB RF amp operation.
>
> http://www.mif.pg.gda.pl/homepages/frank/sheets/088/3/3-500Z.pdf
>
> Best,
>
> Will
>
> *********** REPLY SEPARATOR  ***********
>
> On 6/27/06 at 1:31 PM R L Measures wrote:
>
>> On Jun 27, 2006, at 6:51 AM, Will Matney wrote:
>>
>>> Rich,
>>>
>>> It was the same thing as they printed it I was refering, or to me
>>> it was as I wrote it. It was Eimacs maximum rating at 1 KW input, G-
>>> G, class B RF amp showing it's minimum distortion, or the way they
>>> have it listed.
>>
>> I have seen no info from Eimac on Class B for the 3-500Z.
>>>
>>> Best,
>>>
>>> Will
>>>
>>> *********** REPLY SEPARATOR  ***********
>>>
>>> On 6/27/06 at 6:19 AM R L Measures wrote:
>>>
>>>> On Jun 27, 2006, at 2:46 AM, Tom W8JI wrote:
>>>>
>>>>>> They can be used on up in current, say for pulse circuits
>>>>>> and RF heating. The 400 mA is the maximum plate current at
>>>>>> single tone for minimum distortion. That's for 600 watts
>>>>>> PEP useful power each. That's listed in the tables on page
>>>>>> 2 or 3 under a class B RF amp.
>>>>>
>>>>> Will,
>>>>>
>>>>> Where did you get the idea 400mA is a "minimum distortion"
>>>>> condition?
>>>>
>>>> Good point, Tom.  Will should have said something like:  for  
>>>> minimal
>>>> distortion, the max rated anode-I is 400mA.
>>>>>
>>>>> 73 Tom
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Amps mailing list
>>>>> Amps@contesting.com
>>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>>
>>>>
>>>> R L MEASURES, AG6K. 805-386-3734
>>>> r@somis.org
>>>
>>>
>>>
>>> _______________________________________________
>>> Amps mailing list
>>> Amps@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/amps
>>>
>>
>> R L MEASURES, AG6K. 805-386-3734
>> r@somis.org
>
>
>
>
>
> ------------------------------
>
> Message: 3
> Date: Tue, 27 Jun 2006 13:11:23 -0700
> From: R L Measures <r@somis.org>
> Subject: Re: [Amps] IM distortion and such
> To: "Tom W8JI" <w8ji@w8ji.com>
> Cc: amps@contesting.com
> Message-ID: <5C0B4587-16AC-471C-8C86-370583FA370B@somis.org>
> Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed
>
>
> On Jun 27, 2006, at 11:22 AM, Tom W8JI wrote:
>
>>> Tom,
>>>
>>> It says it on page two of the Eimac 3-500Z spec sheet. See
>>> the one the link was provided for earlier.
>>
>> Single tone carrier level has absolutely nothing to do with
>> operation in a different set of conditions such as two-tone
>> modulation at a different anode voltage, bias, and power
>> level. You are reading more into the data sheet than it is
>> saying.
>
> As I see it, no matter what kind of modulation one is trying to
> amplify, at the point when an incremental increase in input no longer
> increases output (which call the transfer function) by the same
> factor as was observed at lesser currents, the cathode is running out
> steam and the tube is beginning to lose linearity.  Even though there
> is a 3a line on the 3-500Z/ 8002 characteristic curves, does this
> mean that all will be well in linear service at 3 peak anode
> amperes?  If this were the case, at 4kV, single 3-500 linear
> amplifiers could produce 2500w PEP.
>
> OTOH, Tom may be right in saying that tuning up at 550mA produces
> good linearity in an AL-80 or SB-1000, but from the impure matter I
> hear from these two amps on the air that are driven with 100w, I have
> doubts.
>>
>> For a given set of tuning conditions (load line) a person
>> can make the single tone level any level he wants by varying
>> drive and the two-tone test will remain the same as long as
>> the two-tone power level isn't changed. Single tone and
>> two-tone are two totally different conditions, and as the
>> data sheets say other operation is permissible.
>
> But there can be no help if the cathode is running out of emission.
>>
>> Two other random people
>
> What are their callsigns, e-mail addresses, and telephone numbers?
>
>> besides myself have now posted that
>> the did the equivalent of a transfer function (which is what
>> really measures linearity) and both posted the best
>> linearity when the steady-state loadline was established at
>> about 550mA.
>
>
> I don't see how because 550mA corresponds to c. 1650mA peak, which is
> well into the non-linear region.
>
>> Actual performance under one set of conditions
>> cannot be determined by extracting data from a test under
>> totally different conditions.
>
> Peak emission capability is negotiable?
>
> cheerz, Tom
>>
>> 73 Tom
>>
>>
>> _______________________________________________
>> Amps mailing list
>> Amps@contesting.com
>> http://lists.contesting.com/mailman/listinfo/amps
>>
>
> R L MEASURES, AG6K. 805-386-3734
> r@somis.org
>
>
>
>
>
> ------------------------------
>
> Message: 4
> Date: Tue, 27 Jun 2006 13:28:13 -0700
> From: R L Measures <r@somis.org>
> Subject: Re: [Amps] IM distortion and such
> To: "Joe Subich, W4TV" <w4tv@subich.com>
> Cc: amps@contesting.com
> Message-ID: <184482BA-C1F0-4E39-802D-D4B4BB8ED09E@somis.org>
> Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed
>
>
> On Jun 27, 2006, at 9:39 AM, Joe Subich, W4TV wrote:
>
>>
>> No, Will should have said "for minimum distortion at 1 KW PEP
>> input and class B service at 2500 Volts, the maximum plate
>> current at single tone ..."
>>
>> There is no indication that 1KW PEP class B produces more or
>> less distortion that say 1500 W PEP in class AB2 at 3000 V
>> on the plate.  You cannot arbitrarily apply one set of conditions
>> to a completely different set of circumstances.
>>
> Class B has zero ZSAG.  Class AB2's ZSAG is typically 20% of  I-anode
> max.  For Producing IMD, Class B is the queen bee.
>> 73,
>>
>>    ... Joe, W4TV
>>
>>
>>> -----Original Message-----
>>> From: amps-bounces@contesting.com
>>> [mailto:amps-bounces@contesting.com] On Behalf Of R L Measures
>>> Sent: Tuesday, June 27, 2006 9:20 AM
>>> To: Tom W8JI
>>> Cc: craxd1@verizon.net; amps@contesting.com
>>> Subject: Re: [Amps] IM distortion and such
>>>
>>>
>>>
>>> On Jun 27, 2006, at 2:46 AM, Tom W8JI wrote:
>>>
>>>>> They can be used on up in current, say for pulse circuits
>>>>> and RF heating. The 400 mA is the maximum plate current at
>>>>> single tone for minimum distortion. That's for 600 watts
>>>>> PEP useful power each. That's listed in the tables on page
>>>>> 2 or 3 under a class B RF amp.
>>>>
>>>> Will,
>>>>
>>>> Where did you get the idea 400mA is a "minimum distortion"
>>>> condition?
>>>
>>> Good point, Tom.  Will should have said something like:  for minimal
>>> distortion, the max rated anode-I is 400mA.
>>>>
>>>> 73 Tom
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> Amps mailing list
>>>> Amps@contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>
>>>
>>> R L MEASURES, AG6K. 805-386-3734
>>> r@somis.org
>>>
>>>
>>>
>>> _______________________________________________
>>> Amps mailing list
>>> Amps@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/amps
>>>
>>>
>>
>>
>
> R L MEASURES, AG6K. 805-386-3734
> r@somis.org
>
>
>
>
>
> ------------------------------
>
> Message: 5
> Date: Tue, 27 Jun 2006 13:31:08 -0700
> From: R L Measures <r@somis.org>
> Subject: Re: [Amps] IM distortion and such
> To: craxd1@verizon.net
> Cc: amps@contesting.com
> Message-ID: <8E7B071D-D953-4B2A-A6E5-016EED4448A8@somis.org>
> Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed
>
>
> On Jun 27, 2006, at 6:51 AM, Will Matney wrote:
>
>> Rich,
>>
>> It was the same thing as they printed it I was refering, or to me
>> it was as I wrote it. It was Eimacs maximum rating at 1 KW input, G-
>> G, class B RF amp showing it's minimum distortion, or the way they
>> have it listed.
>
> I have seen no info from Eimac on Class B for the 3-500Z.
>>
>> Best,
>>
>> Will
>>
>> *********** REPLY SEPARATOR  ***********
>>
>> On 6/27/06 at 6:19 AM R L Measures wrote:
>>
>>> On Jun 27, 2006, at 2:46 AM, Tom W8JI wrote:
>>>
>>>>> They can be used on up in current, say for pulse circuits
>>>>> and RF heating. The 400 mA is the maximum plate current at
>>>>> single tone for minimum distortion. That's for 600 watts
>>>>> PEP useful power each. That's listed in the tables on page
>>>>> 2 or 3 under a class B RF amp.
>>>>
>>>> Will,
>>>>
>>>> Where did you get the idea 400mA is a "minimum distortion"
>>>> condition?
>>>
>>> Good point, Tom.  Will should have said something like:  for minimal
>>> distortion, the max rated anode-I is 400mA.
>>>>
>>>> 73 Tom
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> Amps mailing list
>>>> Amps@contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>
>>>
>>> R L MEASURES, AG6K. 805-386-3734
>>> r@somis.org
>>
>>
>>
>> _______________________________________________
>> Amps mailing list
>> Amps@contesting.com
>> http://lists.contesting.com/mailman/listinfo/amps
>>
>
> R L MEASURES, AG6K. 805-386-3734
> r@somis.org
>
>
>
>
>
> ------------------------------
>
> Message: 6
> Date: Tue, 27 Jun 2006 20:59:41 GMT
> From: "wc6w@juno.com" <wc6w@juno.com>
> Subject: [Amps] WTB: Johnson SK-650 or Johnson 124-109-1 socket
> To: amps@contesting.com
> Message-ID: <20060627.140039.10883.295404@webmail28.lax.untd.com>
> Content-Type: text/plain
>
> QST
>
> Anyone on the group happen to have an extra Eimac SK-650 socket handy?
>  Or a Johnson 124-109-1
>
> This is the all white plastic version, no metal frame or mounting  
> ears,
> which accetps the 4CX250 family.
>
> I just need one.
>
> 73 & Good afternoon,
>    Marv WC6W
>
>
>
>
>
>
>
>
> *
>
>
> ______________________________________________________________________ 
> __
> Try Juno Platinum for Free! Then, only $9.95/month!
> Unlimited Internet Access with 1GB of Email Storage.
> Visit http://www.juno.com/value to sign up today!
>
>
>
>
> ------------------------------
>
> Message: 7
> Date: Tue, 27 Jun 2006 16:58:08 -0400
> From: "Will Matney" <craxd1@verizon.net>
> Subject: Re: [Amps] IM distortion and such
> To: r@somis.org, amps@contesting.com
> Message-ID: <200606271658080950.08290331@outgoing.verizon.net>
> Content-Type: text/plain; charset=us-ascii
>
> Ok,
>
> I went and pulled my Eimac book down. I hadn't earlier where it was  
> at as I
> couldn't hardly reach it from my wheelchair.
> I guess I need shorter book shelves : ) Anyhow, this one does have  
> the Class
> AB2 listed as below from page 2. Strangely, this one does not  
> mention class
> B like the pdf did.
>
> Quote;
>
> Radio frequency Linear Amplifier
> Cathode driven
> Class AB2
>
> Maximum Ratings:
>
> DC plate voltage 4000 Vdc
> DC plate current 0.4 ampere
> Plate dissapation 500 watts
> Grid dissapation 20 watts
>
> Typical operation (Frequencies to 110 MHz)
> Class AB2, peak envelope or modulation crest conditions
>
>>> (Here I'm going to show the maximum plate voltage they show of  
>>> 3500 Vdc)
>
> Plate voltage 3500 Vdc
> Cathode voltage +15 (+10 at 3000 and 0 at 2500)
> Zero signal plate current 53 mA
> Single-tone plate current, CW 3/4 400 mA
> Two-tone plate current 262 mA
> Single-tone grid current  108 mA
> Two-tone grid current 58 mA
> Single-tone power input 1400 W
> Useful output power, CW or PEP 890 W
> Resonant load impedance 5000 ohms
> Intermodulation distortion products;
> 3rd order -40 dB
> 5th order -45 dB
>
> Single-tone current for 3500 Vdc operation may reach this value  
> during short
> periods of circuit adjustment only.
>
> IMD products are referenced against one tone of a two equal tone  
> signal.
>
> Currents listed corrospond to SSB, or "two-tone" average current at  
> peak of
> signal envelope.
>
> End Quote.
>
> Best,
>
> Will
>
>
>
> *********** REPLY SEPARATOR  ***********
>
> On 6/27/06 at 1:31 PM R L Measures wrote:
>
>> On Jun 27, 2006, at 6:51 AM, Will Matney wrote:
>>
>>> Rich,
>>>
>>> It was the same thing as they printed it I was refering, or to me
>>> it was as I wrote it. It was Eimacs maximum rating at 1 KW input, G-
>>> G, class B RF amp showing it's minimum distortion, or the way they
>>> have it listed.
>>
>> I have seen no info from Eimac on Class B for the 3-500Z.
>>>
>>> Best,
>>>
>>> Will
>>>
>>> *********** REPLY SEPARATOR  ***********
>>>
>>> On 6/27/06 at 6:19 AM R L Measures wrote:
>>>
>>>> On Jun 27, 2006, at 2:46 AM, Tom W8JI wrote:
>>>>
>>>>>> They can be used on up in current, say for pulse circuits
>>>>>> and RF heating. The 400 mA is the maximum plate current at
>>>>>> single tone for minimum distortion. That's for 600 watts
>>>>>> PEP useful power each. That's listed in the tables on page
>>>>>> 2 or 3 under a class B RF amp.
>>>>>
>>>>> Will,
>>>>>
>>>>> Where did you get the idea 400mA is a "minimum distortion"
>>>>> condition?
>>>>
>>>> Good point, Tom.  Will should have said something like:  for  
>>>> minimal
>>>> distortion, the max rated anode-I is 400mA.
>>>>>
>>>>> 73 Tom
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Amps mailing list
>>>>> Amps@contesting.com
>>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>>
>>>>
>>>> R L MEASURES, AG6K. 805-386-3734
>>>> r@somis.org
>>>
>>>
>>>
>>> _______________________________________________
>>> Amps mailing list
>>> Amps@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/amps
>>>
>>
>> R L MEASURES, AG6K. 805-386-3734
>> r@somis.org
>
>
>
>
>
> ------------------------------
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>
> End of Amps Digest, Vol 42, Issue 75
> ************************************
>
>
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>

R L MEASURES, AG6K. 805-386-3734
r@somis.org



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