What tubes is the amp builder going to use for single band amps what bands
do you want them for.
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Today's Topics:
1. Re: Builder Wanted (Louis Parascondola)
2. Re: Pre-Distortion Linearizer (Roger (K8RI))
3. Re: Pre-Distortion Linearizer (Roger (K8RI))
4. Re: Pre-Distortion Linearizer (Fuqua, Bill L)
5. Re: Pre-Distortion Linearizer (Fuqua, Bill L)
6. Re: ?4CX5000A in common grid ?circuit (peter chadwick)
----------------------------------------------------------------------
Message: 1
Date: Sun, 5 May 2013 23:03:37 -0400 (EDT)
From: Louis Parascondola <gudguyham@aol.com>
To: km1h@jeremy.mv.com, n5dx2005@yahoo.com, amps@contesting.com
Subject: Re: [Amps] Builder Wanted
Message-ID: <8D0181D6FFC6793-1B88-60F3@webmail-m147.sysops.aol.com>
Content-Type: text/plain; charset="us-ascii"
I am slowly building mono band amps using Clipperton L amps. The first one
I did is a 160 meter monobander. Easily does legal limit with 100w drive.
-----Original Message-----
From: Carl <km1h@jeremy.mv.com>
To: Kevin Stockton <n5dx2005@yahoo.com>; amps <amps@contesting.com>
Sent: Sun, May 5, 2013 2:02 pm
Subject: Re: [Amps] Builder Wanted
What tube(s)?
Carl
KM1H
----- Original Message -----
From: "Kevin Stockton" <n5dx2005@yahoo.com>
To: <amps@contesting.com>
Sent: Sunday, May 05, 2013 7:46 AM
Subject: [Amps] Builder Wanted
We are looking for an experienced amp builder to build us 6 single band
amplifiers for contest use.
Does anyone have any recommendations?
Thanks,
Kevin, N5DX
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Message: 2
Date: Sun, 05 May 2013 20:53:06 -0700
From: "Roger (K8RI)" <k8ri@rogerhalstead.com>
To: amps@contesting.com
Subject: Re: [Amps] Pre-Distortion Linearizer
Message-ID: <51872922.80008@rogerhalstead.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
On 5/5/2013 3:47 AM, Ian White wrote:
You have a point, Joe; both transmitters and receivers fall into
different classes of performance depending on the price range. But there
is still no valid reason for any transceiver to perform significantly
worse than the comparable "best in class".
Stepping up to a completely different performance class does indeed cost
money; but improving performance to equal the "best in class" is much
more often about attention to detail.
Because there has been such a market-driven obsession with "receiver
numbers" like IP3, the best designers in the development team are
working on the receivers, while the design of the transmitter is
apparently being left to the tea boy. There is a real lack of managerial
- and indeed, moral - imperative to design the best possible transmitter
that can be produced within the given budget.
Another aspect of the "$900 rig problem" is that most of these
transceivers were originally designed for the domestic market in Japan,
which is much more heavily biased towards mobile operation due to the
population density. Many aspects of performance are sacrificed for the
sake of compactness as well as low cost; but in addition to that, they
are specifically designed for operation with relatively inefficient
mobile antennas. That means the receiver needs to be quite sensitive and
the transmitted IMD will be 6-10dB further into the noise. But when the
same radio is used at a fixed station with even a simple wire antenna,
the receiver becomes overly sensitive and has poor strong-signal
handling, while the transmitted IMD looks very poor indeed.
Some years ago, the Japanese manufacturers were quite surprised that
what they thought of as "mobile" transceivers were being marketed in the
West for fixed-station use; but now these $900 rigs have become a major
part of the Western market. Beginners reasonably ask why they should pay
more... and I don't think that anyone is telling them.
And I don't think it would make much of a difference if someone did.
It's not just beginners who use these little rigs in base stations.
Our local group is heavily involved with the NWS and the local EOC from
more than just a weather approach as are two adjoining counties and
their hams. All three have informally standardized on one of those
small rigs for mobile use. Probably between a third and a half also use
those rigs from home. Only a few of us are DX chasers running QRO and I
dont think any of us are using the small rigs from home, but I do know
one who is a serious traffic handler and working regularly on 5B-WAS
with one. I think a number of the traffic handlers are using the small
rigs.
So between the 3 counties, as an educated or SWAG I'd say we probably
have 30 to 50 of those small rigs operating from home stations. Several
are pushing notoriously over rated amps on the bands that are noted for
short tube life. So you start out with a 897D or IC7000 pushing 4 811As
for more than they are worth you do not end up with ideal band
conditions. A number of these stations are pushing their budgets to get
a use 897D let alone a used set of 4 811As.
It's not just that many can't afford more than the $900 dollar rig,
there are a lot more who can't justify one in the car and a better rig
in the house
It's all they can afford so I can't fault them for the rigs they are
using but I can for the way they use them. However many of the
experienced try to "shoe them the way" and why to follow it.
IM figures are difficult to find but I found a QST review of the IC7000
listing 3rd order IM at -33db, but they are regarded as being overly
optimistic.
I haven't been able to find even a QST review on the 897D. The E-Ham
reviews were ... well... shall we say written by those who called it
well constructed and said some were giving it a bum wrap, but I do not
call a rig where the jacks are held only by the solder joints to the PC
board as well constructed.
IOW I did not find the E-Ham reviews to offer any real substance.
I'll leave the realistic IM figures for both rigs to someone who has
done a realistic measurement.
73
Roger (K8RI)
73 from Ian GM3SEK
------------------------------
Message: 3
Date: Sun, 05 May 2013 21:42:30 -0700
From: "Roger (K8RI)" <k8ri@rogerhalstead.com>
To: amps@contesting.com
Subject: Re: [Amps] Pre-Distortion Linearizer
Message-ID: <518734B6.60501@rogerhalstead.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
On 5/5/2013 4:19 AM, peter chadwick wrote:
Manufacturers have gone mad about IMD in receivers but can you use it?
e.g. a +40dBm TOIP with a 10dB NF. In SSB, that's an rx noise floor
of -130dBm and an SFDR of 113dB. To use that, you need phase noise
of -147dBc/Hz averaged over the 3 kHz bandwidth at whatever offset you are
worrying about.....even that leads to a 3dB degradation. So to properly
use that TOIP, the phase noise should be 10dB lower or -157dBc/Hz.
To quote Dominie Sampson "Prodigious!"
Measurements suggest that 95 to 100dB of instantaneous receiver dynamic
range i.e. phase noise or imd limited, is about all the average amateur
needs....
Now how far do you need to improve transmitter wideband noise to make a
difference to other users? Just consider the wide band noise effects of a
250kW broadcast tx on say 7310 and how much trouble that will make.......
Although the degradation from about -30 or -35dB IM3 wrt tone has been
undesirable, I do wonder how much difference it really makes compared with
the effects of 'all knobs clockwise' which we will never stop.
For commercial ISB, the usual requirement has been -36dB wrt PEP, and
that's based on acceptable crud in the wanted sideband. It's unfortunate
that bipolar transistors on 12volts are inherently limited, but that's
what the market appears to want at the moment.
Now is not the time to expect much from the semiconductor industry
either. World wide, I believe the entire industry in in the largest
pull back ,or contraction from poly Silicon to finished devices in its
history.
I mention this as the solar industry is the major user of Silicon and
thus indirectly determines the price price and availability of devices
for the entire semiconductor industry.
Having been associated with the industry almost since its inception, my
own educated guess is, including this year, over the next 3 to 5 years
we will lose between half and 3/4 of the poly producers. After one of
the earlier contractions I believe there were only 3 poly producers left
operating. Recently I believe there were around 60. However I think
only 3 or 4 of those are major world players.
This is an industry noted for its "Feast or Famine" cycles, but jut two
years ago some companies were going through multi Billion dollar
expansions and now we are looking at losing maybe half or more of
existing production. How would you like to be the CFOs who have to
explain "those expenditures that may never start."? It's certainly
cheaper to never start and mothball them rather than run the chemicals
they use through the pipes.
China has been supporting its solar industry with subsidies that would
likely make Solyndra look like pocket change. They couldn't do it
forever. That created a market for poly from other countries as well as
developing their own poly capacity.
This allowed them to sell solar panels cheaper than we could make them
causing the failure of many panel makers.
To top this I believe (for lack of a current figure) that poly which was
selling for more than several hundred US dollars a kilo has dropped to
less than $60 and might go to $20 (my figure, not official and I've been
ouy-of-the-loop for some time.)
The normal cycle would result in culling the producers because of
prices, then the prices would again head for the stratosphere due to low
capacity. The industry has been doing this for over 50 years.
To point out just how sensitive and precariously balanced this industry
is: Many years ago, we developed a method of sawing silicon wafers that
produced 50% less waste. Waste at that time was running 50% so cutting
it in half was a major change that Virtually over night (as long as it
takes to set up the saws) we doubled Silicon production with virtually
no increase in cost. The industry nearly collapsed from over capacity.
Again this all has an effect on the price and availability of chips
throughout the industry as well as development of new devices that we
depend on.
73
Roger (KK8RI)
73
Peter G3RZP
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------------------------------
Message: 4
Date: Mon, 6 May 2013 04:44:09 +0000
From: "Fuqua, Bill L" <wlfuqu00@uky.edu>
To: "Roger (K8RI)" <k8ri@rogerhalstead.com>, "amps@contesting.com"
<amps@contesting.com>
Subject: Re: [Amps] Pre-Distortion Linearizer
Message-ID:
<B7E8B5B4A202074084E2515A7B10A7F30B0BBB0A@ex10mb02.ad.uky.edu>
Content-Type: text/plain; charset="us-ascii"
I have not read all of this thread, a lot said and I just not on computer
much these days.
However, a mulit-op contest station would benefit from a receivers and
transmitters with low IMD as well
as low phase noise. While most operators would not.
However, I have observed that receivers that have fewer mixer and
amplifier stages sound "cleaner" and
"clearer" than those many stages that the signal must past thru before it
gets to your ears.
It seems that many rigs are designed by committee with each designer
responsible for some piece and
they seem to use "cookbook" engineering rather than spending time to
optimize the design with only the
necessary parts to achieve their target. I am just amaze how complex, even
setting aside the synthesizers,
cpus, and fancy displays, transceivers have grown compared to say a KWM-2 or
SB-100.
As I said, just an observation.
73
Bill wa4lav
________________________________________
From: Amps [amps-bounces@contesting.com] on behalf of Roger (K8RI)
[k8ri@rogerhalstead.com]
Sent: Sunday, May 05, 2013 11:53 PM
To: amps@contesting.com
Subject: Re: [Amps] Pre-Distortion Linearizer
On 5/5/2013 3:47 AM, Ian White wrote:
You have a point, Joe; both transmitters and receivers fall into
different classes of performance depending on the price range. But there
is still no valid reason for any transceiver to perform significantly
worse than the comparable "best in class".
Stepping up to a completely different performance class does indeed cost
money; but improving performance to equal the "best in class" is much
more often about attention to detail.
Because there has been such a market-driven obsession with "receiver
numbers" like IP3, the best designers in the development team are
working on the receivers, while the design of the transmitter is
apparently being left to the tea boy. There is a real lack of managerial
- and indeed, moral - imperative to design the best possible transmitter
that can be produced within the given budget.
Another aspect of the "$900 rig problem" is that most of these
transceivers were originally designed for the domestic market in Japan,
which is much more heavily biased towards mobile operation due to the
population density. Many aspects of performance are sacrificed for the
sake of compactness as well as low cost; but in addition to that, they
are specifically designed for operation with relatively inefficient
mobile antennas. That means the receiver needs to be quite sensitive and
the transmitted IMD will be 6-10dB further into the noise. But when the
same radio is used at a fixed station with even a simple wire antenna,
the receiver becomes overly sensitive and has poor strong-signal
handling, while the transmitted IMD looks very poor indeed.
Some years ago, the Japanese manufacturers were quite surprised that
what they thought of as "mobile" transceivers were being marketed in the
West for fixed-station use; but now these $900 rigs have become a major
part of the Western market. Beginners reasonably ask why they should pay
more... and I don't think that anyone is telling them.
And I don't think it would make much of a difference if someone did.
It's not just beginners who use these little rigs in base stations.
Our local group is heavily involved with the NWS and the local EOC from
more than just a weather approach as are two adjoining counties and
their hams. All three have informally standardized on one of those
small rigs for mobile use. Probably between a third and a half also use
those rigs from home. Only a few of us are DX chasers running QRO and I
dont think any of us are using the small rigs from home, but I do know
one who is a serious traffic handler and working regularly on 5B-WAS
with one. I think a number of the traffic handlers are using the small
rigs.
So between the 3 counties, as an educated or SWAG I'd say we probably
have 30 to 50 of those small rigs operating from home stations. Several
are pushing notoriously over rated amps on the bands that are noted for
short tube life. So you start out with a 897D or IC7000 pushing 4 811As
for more than they are worth you do not end up with ideal band
conditions. A number of these stations are pushing their budgets to get
a use 897D let alone a used set of 4 811As.
It's not just that many can't afford more than the $900 dollar rig,
there are a lot more who can't justify one in the car and a better rig
in the house
It's all they can afford so I can't fault them for the rigs they are
using but I can for the way they use them. However many of the
experienced try to "shoe them the way" and why to follow it.
IM figures are difficult to find but I found a QST review of the IC7000
listing 3rd order IM at -33db, but they are regarded as being overly
optimistic.
I haven't been able to find even a QST review on the 897D. The E-Ham
reviews were ... well... shall we say written by those who called it
well constructed and said some were giving it a bum wrap, but I do not
call a rig where the jacks are held only by the solder joints to the PC
board as well constructed.
IOW I did not find the E-Ham reviews to offer any real substance.
I'll leave the realistic IM figures for both rigs to someone who has
done a realistic measurement.
73
Roger (K8RI)
73 from Ian GM3SEK
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------------------------------
Message: 5
Date: Mon, 6 May 2013 04:49:26 +0000
From: "Fuqua, Bill L" <wlfuqu00@uky.edu>
To: "Roger (K8RI)" <k8ri@rogerhalstead.com>, "amps@contesting.com"
<amps@contesting.com>
Subject: Re: [Amps] Pre-Distortion Linearizer
Message-ID:
<B7E8B5B4A202074084E2515A7B10A7F30B0BBB1C@ex10mb02.ad.uky.edu>
Content-Type: text/plain; charset="us-ascii"
The last great subsidy in manufacturing and electronics industry was the
1960's space race.
I expect we will never see another like it.
73
Bill wa4lav
------------------------------
Message: 6
Date: Mon, 06 May 2013 10:00:00 +0200
From: peter chadwick <g8on@fsmail.net>
To: Markku Oksanen <markku.a.oksanen@kolumbus.fi>,
"amps@contesting.com" <amps@contesting.com>
Subject: Re: [Amps] ?4CX5000A in common grid ?circuit
Message-ID: <4018462.1151367827200349.JavaMail.www@wwinf3708>
Content-Type: text/plain; charset=UTF-8
Hi Markku,
Have a look at 'Single Sideband Principals and Circuits' by Pappenfus,
Bruene and Schoenike - the 1964 edition. Or better, see if your local
library can get you a copy of the article.
E.L.Chaffee, A Simplified Harmonic Analysis, Rev. Sci. Instr., pp384-389,
October 1936.
If need be, I'll scan the pages from Pappenfus for you.
The main difference between estimating gain in grounded cathode and grounded
grid is that you need to take into account the negative feedback.
The gain in Class A is given by {RL/(Rp + RL)}{mu + 1} = {RL/(Rp + RL)}
{[gm.Rp] + 1}: in other classes, the variation in gm over the cycle will
have some effect.
For a tetrode or pentode, Rp is fairly high.
73
Peter G3RZP
========================================
Message Received: May 06 2013, 06:51 AM
From: "Markku Oksanen" <markku.a.oksanen@kolumbus.fi>
To: "g8on@fsmail.net" <g8on@fsmail.net>, "amps@contesting.com"
<amps@contesting.com>
Cc:
Subject: RE: [Amps] ?4CX5000A in common grid ?circuit
Hi Peter, All
First, it looks like my posts don't go to the list at all for some reason
but naturally reach direct emails.
What is mean by muu here is "muu" in the sense it appears in discussion and
formulas for triode GG power gain.
I believe I am making this a bit more complicated than necessary by trying
to calculate the Tetrode GG power gain from first principles but I would
finally like to understand how this works compared to a simple, high muu
triode in GG.
Not being familiar with the Chaffee analysis, (google helped none), could
you point me to the correct direction here.Going through the motions with
the characteristic curves is not a problem, just an other little interesting
task in this project.
The main reason for GG thinking for this tube was simplicity and perhaps
additional better IMD from inherent RF feedback in GG setup. And I have
build grid driven amps and would like to do something different....
Thanks for the help!
MarkkuWW1C
Date: Mon, 6 May 2013 00:20:30 +0200
From: g8on@fsmail.net
To: markku.a.oksanen@kolumbus.fi; km1h@jeremy.mv.com;
villelintervo@hotmail.com; amps@contesting.com
Subject: Re: [Amps] 4CX5000A in common grid circuit
I'm not sure what you mean here by mu.
mu is dVp/dVg. Gm is dIp/dVg and ra is dVp/dIp
so mu is Gm times ra.
So for any given screen voltage, you can figure the mu, because at a given
grid voltage, Va has increased or decreased (depending on phase) with
control grid voltage and you can then figure out the plate current.
Likewise, you can fix the screen volts and calculate the plate current at
various points in the cycle and then apply Chaffee analysis.
OK, it's long and messy but can be done by hand from the characteristic
curves......
73
Peter G3RZP
========================================
Message Received: May 05 2013, 09:38 PM
From: "Markku Oksanen" <markku.a.oksanen@kolumbus.fi>
To: "Carl" <km1h@jeremy.mv.com>, "g8on@fsmail.net" <g8on@fsmail.net>,
"Ville Lintervo" <villelintervo@hotmail.com>, "amps@contesting.com"
<amps@contesting.com>
Cc:
Subject: RE: [Amps] 4CX5000A in common grid circuit
Hi
I have all the components to build the grid supplies to fit the need,
screen to +1600 V if necessary.I know the DC operating conditions need to
be about the same no matter what the RF configuration is.
I would still hope to find the a way to calculate the power gain in GG.I
have a hard time finding the a way to translate tetrode (grid to screen
grid) muu to equivalent triode muu.Or perhaps this is a silly question.
Thanks
MarkkuWW1C
> From: km1h@jeremy.mv.com
> To: g8on@fsmail.net; villelintervo@hotmail.com; amps@contesting.com
> Date: Sun, 5 May 2013 09:41:01 -0400
> Subject: Re: [Amps] FW: 4CX5000A in common grid circuit
>
> That is a typical British understatement (-;
>
> But also typical of many European signals.
>
> Carl
>
>
>
>
> >
> > The G2DAF configuration has had, over many years, a very poor
reputation
> > for producing broad signals.
> >
> > 73
> >
> > Peter G3RZP
> >
> > ========================================
> > Message Received: May 05 2013, 11:07 AM
> > From: "Ville Lintervo" <villelintervo@hotmail.com>
> > To: "amps@contesting.com" <amps@contesting.com>
> > Cc:
> > Subject: Re: [Amps] FW: 4CX5000A in common grid circuit
> >
> > Markku, Have you given a thought for g2daf -configuration tog serve
your
> > purposes ? http://www.g4dmp.co.uk/g2daf-lin.pdfSM2CEW describes his
> > implementation with QBL5/3500 http://www.sm2cew.com/ampli.html Ville
> > oh1jd
> >
> >
> > _______________________________________________
> > 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
> >
> >
> > -----
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> > Checked by AVG - www.avg.com
> > Version: 10.0.1432 / Virus Database: 3162/5799 - Release Date:
05/05/13
> >
>
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