It occurs to me Ameritron may be trying to compensate for operators who
do not 'scope their station. With an oscilloscope you can see how
undercoupling
the output causes the tube to flat top. That creates distortion, both IM and
harmonic. It seems to me that Ameritron, with their suggested tuning method
insures the tubes are overcoupled and then underdriven.
We have all heard the square wave clipping during contests where the Bozo
operators
take 10-12 Khz with a severly overdriven radios and amplifiers.
I used RF clipping in my Drake stuff in the 60's and 70's, but there we had
passband filters insuring the energey was contained in the 2.8 khz passband
of
the exciter (Magnum 6). RF clipping isn't popular anymore, we want to
eliminate it
in our stations to stay clean and no "nastygrams" from OOs.
Respectfully submitted;
Ed K0KL
-----Original Message-----
From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com]On
Behalf Of amps-request@contesting.com
Sent: Monday, June 26, 2006 8:37 PM
To: amps@contesting.com
Subject: Amps Digest, Vol 42, Issue 67
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Today's Topics:
1. L-4B connector (Tom Sessions)
2. Re: AL-80B questions (Peter Chadwick)
3. Re: IM distortion and such (Bill Coleman)
4. Re: IM distortion and such (Mike Sawyer)
5. Re: IM distortion and such (Bill Coleman)
6. Re: IM distortion and such (Will Matney)
7. Re: L-4B connector (Will Matney)
8. Re: IM distortion and such (Will Matney)
----------------------------------------------------------------------
Message: 1
Date: Tue, 27 Jun 2006 00:25:29 -0000
From: "Tom Sessions" <radio_k4rv@peoplepc.com>
Subject: [Amps] L-4B connector
To: <amps@contesting.com>
Message-ID: <000701c69980$329ef660$27e0133f@Peggy>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
I need a connector for my L-4B power supply, the one for the end of the cord
that plugs onto the back of the L-4B. It has eight terminals.
(1) Anybody got a spare for sale?
(2) Where can one be obtained?
Thanks/73
Tom K4RV
------------------------------
Message: 2
Date: Tue, 27 Jun 2006 02:45:08 +0200 (CEST)
From: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Subject: Re: [Amps] AL-80B questions
To: Steve Katz <stevek@jmr.com>, "'dcoffman@iquest.net'"
<dcoffman@iquest.net>, Tom W8JI <w8ji@w8ji.com>
Cc: amps@contesting.com
Message-ID: <31997389.1151369108224.JavaMail.www@wwinf3201>
Content-Type: text/plain; charset=UTF-8
OK, probably a stupid question. Are we sure that the tuning point with
minimum input capacitance is actually tuned to 50MHz, and not 100MHz, with
the stage acting as a power doubler?
73
Peter G3RZP
------------------------------
Message: 3
Date: Mon, 26 Jun 2006 20:53:45 -0400
From: Bill Coleman <aa4lr@arrl.net>
Subject: Re: [Amps] IM distortion and such
To: Tom W8JI <w8ji@w8ji.com>
Cc: amps@contesting.com
Message-ID: <A4570471-E094-4F33-AC09-F18D08ADDE6B@arrl.net>
Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed
On Jun 26, 2006, at 6:03 AM, Tom W8JI wrote:
> The original subject was the manual of the AL80 says to load
> to 550mA and then as a final step back off drive to obtain
> 400mA. This ensures the loading is heavy enough and grid
> current is proper to handle ALC overshoots common with
> exciters. That horrified a couple people, ...
I don't know why. With just a little bit of searching, I found a
3-500Z spec sheet that clearly shows constant current curves going as
high as 2.2 amps! (Here:<http://www.mif.pg.gda.pl/homepages/frank/
sheets/088/3/3-500Z.pdf>)
So much for the claim that the 3-500Z can't pass more than 420 mA....
Besides, if it offends people, they can just tune their amps some
other way.
I don't see what the big deal is.
Bill Coleman, AA4LR, PP-ASEL Mail: aa4lr@arrl.net
Quote: "Not within a thousand years will man ever fly!"
-- Wilbur Wright, 1901
------------------------------
Message: 4
Date: Mon, 26 Jun 2006 21:15:04 -0400
From: "Mike Sawyer" <w3slk@uplink.net>
Subject: Re: [Amps] IM distortion and such
To: "Bill Coleman" <aa4lr@arrl.net>, "Tom W8JI" <w8ji@w8ji.com>
Cc: amps@contesting.com
Message-ID: <004501c69987$20a8dcd0$c8d69741@D9PBT931>
Content-Type: text/plain; charset="Windows-1252"
Bill said: .....I don't know why. With just a little bit of searching, I
found a
3-500Z spec sheet that clearly shows constant current curves going as
high as 2.2 amps! (Here:<http://www.mif.pg.gda.pl/homepages/frank/
sheets/088/3/3-500Z.pdf>)
So much for the claim that the 3-500Z can't pass more than 420 mA....
I call your attention to that same link where it refers to 'RF Linear
Amplifier Grounded Grid, Class B'. It clearly states: Maximum Ratings
DC Plate Voltage........ 4000 Volts
DC Plate Current........ 0.400 Amp
Plate Dissipation........ 500 Watts
Grid Dissipation........ 20 Watts
I think someone ought to recant their statements with regards to what the
manufacturer's maximum rating specifications.
Mod-U-Lator,
Mike(y)
W3SLK
----- Original Message -----
From: "Bill Coleman" <aa4lr@arrl.net>
To: "Tom W8JI" <w8ji@w8ji.com>
Cc: <amps@contesting.com>
Sent: Monday, June 26, 2006 8:53 PM
Subject: Re: [Amps] IM distortion and such
On Jun 26, 2006, at 6:03 AM, Tom W8JI wrote:
> The original subject was the manual of the AL80 says to load
> to 550mA and then as a final step back off drive to obtain
> 400mA. This ensures the loading is heavy enough and grid
> current is proper to handle ALC overshoots common with
> exciters. That horrified a couple people, ...
I don't know why. With just a little bit of searching, I found a
3-500Z spec sheet that clearly shows constant current curves going as
high as 2.2 amps! (Here:<http://www.mif.pg.gda.pl/homepages/frank/
sheets/088/3/3-500Z.pdf>)
So much for the claim that the 3-500Z can't pass more than 420 mA....
Besides, if it offends people, they can just tune their amps some
other way.
I don't see what the big deal is.
Bill Coleman, AA4LR, PP-ASEL Mail: aa4lr@arrl.net
Quote: "Not within a thousand years will man ever fly!"
-- Wilbur Wright, 1901
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
------------------------------
Message: 5
Date: Mon, 26 Jun 2006 21:17:21 -0400
From: Bill Coleman <aa4lr@arrl.net>
Subject: Re: [Amps] IM distortion and such
To: craxd1@verizon.net
Cc: amps@contesting.com
Message-ID: <A028D76D-4676-4E22-BCD0-29B47D3762C6@arrl.net>
Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed
On Jun 26, 2006, at 10:51 AM, Will Matney wrote:
> Now what if a designer said they'd carry a 40 amp load at 10
> amperes a piece? How long would they last at this output? Would
> Motorola warranty them at this? What kind of reputation would the
> manufacturer get over their power supplies blowing pass transistors
> under full load? Are they willing to replace the product? Are they
> ready for a law suit from a disgruntled customer? The design falls
> back on the engineer, his license, and liability at worse case.
> Where I worked in mining machinery, it occurred often.
In mechanical engineering, they usually refer to this as a "design
rule". For example, light aircraft are typically designed to
withstand 3.8 positive Gs (in the Normal category). But, you wouldn't
build a structure that can just withstand 3.8 positive Gs and then
fail. No, you'd design a structure that could withstand 1.5 to 2.5
times MORE, depending on the materials and construction techniques.
Aircraft are a good example, because that extra strength comes at a
price: weight. Excess weight costs aircraft dearly in nearly every
performance category. The design rule is purposely kept low.
The design rule allows you to compensate for factors that are beyond
your control, such as differences in assembly, deterioration of
materials, improper use, improper installation.
Design rules vary depending on the type of design. Man-carrying
equipment, for example, requires, by law, design rules of 10 or more.
That's why that clip for your tower belt is rated for 5000 lbs, even
though it isn't even likely to see 500 lbs.
--
The AL-80A and AL-80B have been around long enough to establish a
positive track record. It's pretty clear, that regardless of what the
manual says, these units are not self-destructing because of
excessive plate current.
Bill Coleman, AA4LR, PP-ASEL Mail: aa4lr@arrl.net
Quote: "Not within a thousand years will man ever fly!"
-- Wilbur Wright, 1901
------------------------------
Message: 6
Date: Mon, 26 Jun 2006 20:46:37 -0400
From: "Will Matney" <craxd1@verizon.net>
Subject: Re: [Amps] IM distortion and such
To: amps@contesting.com
Message-ID: <200606262046370920.03D3AAEC@outgoing.verizon.net>
Content-Type: text/plain; charset=us-ascii
Mike,
I was at the Kentucky licensure website several years back, and you could
download the whole state law on this. I did and read it through. It said
that if you designed any equipment for the public that was electrical, you
were supposed to carry a valid engineers license in that state. To be a PE
there, you had to have a 4 year BSc degree in the field, then work for two
more years under a licensed PE as an EIT to be allowed to take the test. If
you then could pass the test, you were granted your license. I then e-mailed
the director about what I had read and asked what all was included under
design. He wrote back and told me it meant everything, and that designing
anything without a license was breaking the law. He also mentioned that even
using the term engineer with your name was considered illegal. I don't have
the link to the website, but you can look this all up there if they haven't
changed it. The director does answer the e-mails also.
Now the way a lot of companies get around this is hiring ones without a
license and placing them under a licensed engineer as a "designer" or
"draftsman". They'll have like a VP of Engineering who is licensed, and will
view over any drawing before they hit the shop, or any materials purchased.
That's the way I worked at both places as I never wanted to get a license
over law suits. Belive me, my boss was tied up in every one they had and it
was several at a time where it was mining related. You have people out there
who are just waiting to say they got hurt off a piece of equipment to file a
law suit. I helped bust one of these by designing and building a full scale
model of a drill arm with wood. The guy suing was required to show how it
happened in court, and his butt couldn't hit the lever that he claimed
caused his hand to be mashed. The man was found to have done this his self!
After it got out, two other employees stepped forward and verified what the
guy done.
Another way around this if you own a business is to have an EE or ME look at
all the prints, ok the design, and stamp it. That relieves you of any
liability. I did this when I ran the shop I had as I was building equipment
for the railroads and the coal mines. I had friends doing both, and I paid
them for their professional services.
I think the state licensure boards turn a blind eye to a lot unless someone
reports something or your a large corporation. Then, if they do, you better
have all your ducks in a row, or one could be looking at both fines and jail
time. If you get a chance, drop by that website, or e-mail the director. He
can enlighten you more really than the law that is written as he knows how
the courts interpret it.
Best,
Will
*********** REPLY SEPARATOR ***********
On 6/26/06 at 3:44 PM Michael Tope wrote:
>----- Original Message -----
>From: "Will Matney" <craxd1@verizon.net>
>
>> Gary,
>>
>> You would think being sued is the worst part. What if a disgruntled
>> customer reported you to the state license board? You would then have a
>> review about your engineering license. Here, they beileve the reporter
>> more, and your guilty to them having to prove yourself innocent. If they
>> pull your license, you can no longer be an engineer. If one even says
>that
>> you can do this over a limit, and they see this, you could sure loose
>that
>> slip of paper and your stamp. According to how bad it is, or what all
>the
>> reporter said to them, it could be a temporary suspension all the way to
>a
>> permenant. It's according to what you can prove. Then, I guess one could
>> find a job as a draftsman or in sales. It's worse today too. People have
>> gotten law suit crazy, and attorneys don't hold no punches back if they
>> think there's extra money they can collect. Even if you fight all this
>> succesfully, how much out of pocket expense did it cost you? Even though
>> things can be done over the limit, I will har
>> dly ever tell someone to do something other than published standards.
>> Heck, if you tell someone to build something some way, and it doesn't
>work
>> out, you can be in trouble for doing engineering without a license! That
>> is if someone is mad enough to report you. Another thing is if you've
>> designed something to be used by another manufacturer. They will sue for
>> down time if your product caused it. That can run into tons of money.
>The
>> reason I know about this is I used to have to design and build full
>scale
>> mock ups or models of our equipment to be used in court cases. I've
>heard
>> some of the craziest stories about law suits that can be heard. It's a
>> shame to say, but today, people will sue you at the drop of a hat.
>>
>> Best,
>>
>> Will
>>
>>
>
>Will,
>
>Since when do you need a PE license to be an electronic design engineer?
>Only a handful of the design engineers that I have worked with over the
>years actually had a PE license.
>
>73, Mike W4EF........................................
>
>
>_______________________________________________
>Amps mailing list
>Amps@contesting.com
>http://lists.contesting.com/mailman/listinfo/amps
------------------------------
Message: 7
Date: Mon, 26 Jun 2006 20:55:23 -0400
From: "Will Matney" <craxd1@verizon.net>
Subject: Re: [Amps] L-4B connector
To: "Tom Sessions" <radio_k4rv@peoplepc.com>, amps@contesting.com
Message-ID: <200606262055230390.03DBAFF3@outgoing.verizon.net>
Content-Type: text/plain; charset=us-ascii
Tom,
I've seen both the 8 and 11 pins on ebay with ready made cords out of rotor
cable which most used. I think they're wired for Heathkit stuff though, but
the guy has single connectors also. I can't remember who made these as you
can't hardly find them now. The square types with the flat terminlas are
made by Cinch and available everywhere. If I recall, your's is the round
type?
Best,
Will
*********** REPLY SEPARATOR ***********
On 6/27/06 at 12:25 AM Tom Sessions wrote:
>I need a connector for my L-4B power supply, the one for the end of the
>cord
>that plugs onto the back of the L-4B. It has eight terminals.
>
>(1) Anybody got a spare for sale?
>
>(2) Where can one be obtained?
>
>Thanks/73
>Tom K4RV
>
>_______________________________________________
>Amps mailing list
>Amps@contesting.com
>http://lists.contesting.com/mailman/listinfo/amps
------------------------------
Message: 8
Date: Mon, 26 Jun 2006 21:28:58 -0400
From: "Will Matney" <craxd1@verizon.net>
Subject: Re: [Amps] IM distortion and such
To: amps@contesting.com
Message-ID: <200606262128580380.03FA7037@outgoing.verizon.net>
Content-Type: text/plain; charset=us-ascii
Bill,
I totally agree with everything you said. I'm not trying to down the AL-80,
it's just saying that in the manual can set a company up for liability. That
was the point I was trying to get across. If Ameritron has a letter from
Eimac saying it's ok, then they are relieved of the liability.
By the way, the factor you mention, I always called the fudge factor or
safety factor. Same thing all around : )
Best,
Will
*********** REPLY SEPARATOR ***********
On 6/26/06 at 9:17 PM Bill Coleman wrote:
>On Jun 26, 2006, at 10:51 AM, Will Matney wrote:
>
>> Now what if a designer said they'd carry a 40 amp load at 10
>> amperes a piece? How long would they last at this output? Would
>> Motorola warranty them at this? What kind of reputation would the
>> manufacturer get over their power supplies blowing pass transistors
>> under full load? Are they willing to replace the product? Are they
>> ready for a law suit from a disgruntled customer? The design falls
>> back on the engineer, his license, and liability at worse case.
>> Where I worked in mining machinery, it occurred often.
>
>In mechanical engineering, they usually refer to this as a "design
>rule". For example, light aircraft are typically designed to
>withstand 3.8 positive Gs (in the Normal category). But, you wouldn't
>build a structure that can just withstand 3.8 positive Gs and then
>fail. No, you'd design a structure that could withstand 1.5 to 2.5
>times MORE, depending on the materials and construction techniques.
>
>Aircraft are a good example, because that extra strength comes at a
>price: weight. Excess weight costs aircraft dearly in nearly every
>performance category. The design rule is purposely kept low.
>
>The design rule allows you to compensate for factors that are beyond
>your control, such as differences in assembly, deterioration of
>materials, improper use, improper installation.
>
>Design rules vary depending on the type of design. Man-carrying
>equipment, for example, requires, by law, design rules of 10 or more.
>That's why that clip for your tower belt is rated for 5000 lbs, even
>though it isn't even likely to see 500 lbs.
>
>--
>
>The AL-80A and AL-80B have been around long enough to establish a
>positive track record. It's pretty clear, that regardless of what the
>manual says, these units are not self-destructing because of
>excessive plate current.
>
>Bill Coleman, AA4LR, PP-ASEL Mail: aa4lr@arrl.net
>Quote: "Not within a thousand years will man ever fly!"
> -- Wilbur Wright, 1901
>
>_______________________________________________
>Amps mailing list
>Amps@contesting.com
>http://lists.contesting.com/mailman/listinfo/amps
------------------------------
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End of Amps Digest, Vol 42, Issue 67
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