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The amp I would like to see Elecraft build.

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Dan Baker

The amp I would like to see Elecraft build.

Once the FCC removes the 15 dB gain limitation on amateur amplifiers *Petition
for Rule Making* (*RM-11767*
<http://apps.fcc.gov/ecfs/comment/view?id=60001536394>) Then Elecraft can
build us a 12 volt version of the KPA500. That would give us the ability to
run our KX’s as a very effective mobile rig. This would compliment
Elecrafts theme of products much more than a legal limit amp, that really
you can find anywhere.

73, Dan KM6CQ

Don't sacrifice your hobby
for the right house.
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Joe Subich, W4TV-4

Re: The amp I would like to see Elecraft build.

> Then Elecraft can build us a 12 volt version of the KPA500.

Heaven help us, NO! The 12V amplifiers are marginally clean enough
at 100W. A 500W 12V amplifier is likely to have IMD be much poorer
than -30 dB PEP. What we really need is a 48V final for the K3/K3S
(maybe at 200W) so we can see IMD in the -45 dB to -50 dB PEP range
where it really should be.

It's time to make a stand for cleaner signals ... not signals in the
same class as the "no name" Italian and Chinese amplifiers.

73,

... Joe, W4TV

On 7/31/2016 8:30 PM, Dan Baker wrote:

> Once the FCC removes the 15 dB gain limitation on amateur amplifiers *Petition
> for Rule Making* (*RM-11767*
> <http://apps.fcc.gov/ecfs/comment/view?id=60001536394>) Then Elecraft can
> build us a 12 volt version of the KPA500. That would give us the ability to
> run our KX’s as a very effective mobile rig. This would compliment
> Elecrafts theme of products much more than a legal limit amp, that really
> you can find anywhere.
>
> 73, Dan KM6CQ
>
> Don't sacrifice your hobby
> for the right house.
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
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>

Bob Nielsen-4

Re: The amp I would like to see Elecraft build.

In reply to this post by Dan Baker

Although it would add to the cost, building in a 12 to 60 volt DC-DC
converter would avoid compromising the performance.

73, Bob N7XY

On 7/31/16 7:15 PM, Ron D'Eau Claire wrote:

> Dan, the issue is producing more than 100 watts from a 12-volt supply without unacceptable levels of IMD. That's why Elecraft used a 60-volt power supply in the KPA500.
>
> If the gain restrictions are removed, Elecraft (and anyone else) could produce a 500 watt amplifier that worked from an exciter with any level of drive, even less than 1 watt.
>
> 73, Ron AC7AC
>
>
>
> -----Original Message-----
> From: Elecraft [mailto:[hidden email]] On Behalf Of Dan Baker
> Sent: Sunday, July 31, 2016 5:31 PM
> To: [hidden email]
> Subject: [Elecraft] The amp I would like to see Elecraft build.
>
> Once the FCC removes the 15 dB gain limitation on amateur amplifiers *Petition for Rule Making* (*RM-11767*
> <http://apps.fcc.gov/ecfs/comment/view?id=60001536394>) Then Elecraft can build us a 12 volt version of the KPA500. That would give us the ability to run our KX’s as a very effective mobile rig. This would compliment Elecrafts theme of products much more than a legal limit amp, that really you can find anywhere.
>
> 73, Dan KM6CQ

Gary K9GS

Re: The amp I would like to see Elecraft build.

Or better yet, do what other SS amp manufacturer's are doing, use
surplus HP Proliant server power supplies? Here's a 3KW one/50V for
$30.00. There are warehouses full of these things available.

http://www.ebay.com/itm/HP-ESP120-2950W-Power-Supply-226519-501-406424-001-253232-001/391114939625?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D37577%26meid%3D7a666926576944989b8c1bc8c2e7ec53%26pid%3D100005%26rk%3D1%26rkt%3D6%26sd%3D122038440431

They have other current capacities available. These can be run in
series or parallel too.

Sure beats re-inventing the wheel.

On 8/1/2016 1:04 AM, Bob Nielsen wrote:

> Although it would add to the cost, building in a 12 to 60 volt DC-DC
> converter would avoid compromising the performance.
>
> 73, Bob N7XY
>
> On 7/31/16 7:15 PM, Ron D'Eau Claire wrote:
>> Dan, the issue is producing more than 100 watts from a 12-volt supply
>> without unacceptable levels of IMD. That's why Elecraft used a
>> 60-volt power supply in the KPA500.
>>
>> If the gain restrictions are removed, Elecraft (and anyone else)
>> could produce a 500 watt amplifier that worked from an exciter with
>> any level of drive, even less than 1 watt.
>>
>> 73, Ron AC7AC
>>
>>
>>
>> -----Original Message-----
>> From: Elecraft [mailto:[hidden email]] On Behalf Of
>> Dan Baker
>> Sent: Sunday, July 31, 2016 5:31 PM
>> To: [hidden email]
>> Subject: [Elecraft] The amp I would like to see Elecraft build.
>>
>> Once the FCC removes the 15 dB gain limitation on amateur amplifiers
>> *Petition for Rule Making* (*RM-11767*
>> <http://apps.fcc.gov/ecfs/comment/view?id=60001536394>) Then Elecraft
>> can build us a 12 volt version of the KPA500. That would give us the
>> ability to run our KX’s as a very effective mobile rig. This would
>> compliment Elecrafts theme of products much more than a legal limit
>> amp, that really you can find anywhere.
>>
>> 73, Dan KM6CQ
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
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--
73,

Gary K9GS

Greater Milwaukee DX Association: http://www.gmdxa.org
Society of Midwest Contesters: http://www.w9smc.com
CW Ops #1032 http://www.cwops.org

************************************************

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Lewis Phelps

Re: The amp I would like to see Elecraft build.

I picked up one of these things at a local surplus store. Noisy as hell. Not a good idea.

Lew N6LEW

> On Aug 1, 2016, at 7:35 PM, Gary K9GS <[hidden email]> wrote:
>
> Or better yet, do what other SS amp manufacturer's are doing, use surplus HP Proliant server power supplies? Here's a 3KW one/50V for $30.00. There are warehouses full of these things available.
>
> http://www.ebay.com/itm/HP-ESP120-2950W-Power-Supply-226519-501-406424-001-253232-001/391114939625?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D37577%26meid%3D7a666926576944989b8c1bc8c2e7ec53%26pid%3D100005%26rk%3D1%26rkt%3D6%26sd%3D122038440431 <http://www.ebay.com/itm/HP-ESP120-2950W-Power-Supply-226519-501-406424-001-253232-001/391114939625?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D37577%26meid%3D7a666926576944989b8c1bc8c2e7ec53%26pid%3D100005%26rk%3D1%26rkt%3D6%26sd%3D122038440431>
>
> They have other current capacities available. These can be run in series or parallel too.
>
> Sure beats re-inventing the wheel.
>
>
> On 8/1/2016 1:04 AM, Bob Nielsen wrote:
>> Although it would add to the cost, building in a 12 to 60 volt DC-DC converter would avoid compromising the performance.
>>
>> 73, Bob N7XY
>>
>> On 7/31/16 7:15 PM, Ron D'Eau Claire wrote:
>>> Dan, the issue is producing more than 100 watts from a 12-volt supply without unacceptable levels of IMD. That's why Elecraft used a 60-volt power supply in the KPA500.
>>>
>>> If the gain restrictions are removed, Elecraft (and anyone else) could produce a 500 watt amplifier that worked from an exciter with any level of drive, even less than 1 watt.
>>>
>>> 73, Ron AC7AC
>>>
>>>
>>>
>>> -----Original Message-----
>>> From: Elecraft [mailto:[hidden email]] On Behalf Of Dan Baker
>>> Sent: Sunday, July 31, 2016 5:31 PM
>>> To: [hidden email]
>>> Subject: [Elecraft] The amp I would like to see Elecraft build.
>>>
>>> Once the FCC removes the 15 dB gain limitation on amateur amplifiers *Petition for Rule Making* (*RM-11767*
>>> <http://apps.fcc.gov/ecfs/comment/view?id=60001536394>) Then Elecraft can build us a 12 volt version of the KPA500. That would give us the ability to run our KX’s as a very effective mobile rig. This would compliment Elecrafts theme of products much more than a legal limit amp, that really you can find anywhere.
>>>
>>> 73, Dan KM6CQ
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to [hidden email] <mailto:[hidden email]>
>
> --
> 73,
>
> Gary K9GS
>
> Greater Milwaukee DX Association: http://www.gmdxa.org <http://www.gmdxa.org/>
> Society of Midwest Contesters: http://www.w9smc.com <http://www.w9smc.com/>
> CW Ops #1032 http://www.cwops.org <http://www.cwops.org/>
>
> ************************************************
>
>
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Lew Phelps N6LEW
Pasadena, CA DM04wd
Elecraft K3-10 / KXV144 / XV432
Yaesu FT-7800
[hidden email]
www.n6lew.us

Generalized Law of Entropy: Sooner or later, everything that has been put together will fall apart.

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Wes Stewart-2

Re: The amp I would like to see Elecraft build.

In reply to this post by Joe Subich, W4TV-4

I'm not always on the same page as Joe, but this time I could not agree more.
As someone who has measured the TX IMD of both my kit K3/100 and a factory built
K3S/100 I can attest to this. First of all, they like every other manufacturer
and the ARRL fudge the numbers by 6 dB (in their favor of course) by comparing
one distortion product to the sum of the two tones.

EIMAC and MIL-Specs say, "The standard method of specifying the magnitude of the
distortion products is to specify the reduction in decibels of
one product from one tone of a two-equal-tone signal."

Elecraft isn't to be singled out for this, they are just doing what the ham
industry is doing.

One of several motivations for replacing a perfectly working K3 with the K3S was
the hope that the FET PA would be cleaner than the bipolar PA in the K3. Big
disappointment. One factor is the fact that it's still a nominal "12 V" PA.
Another is that it's still driven by a bipolar "10 W" exciter. If some of you
are using a bare K3/10 and running at greater than 10 W, shame on you. And
shame on Elecraft for letting you do it. Based upon my measurements (which BTW
correlated to 1 dB or less with Elecraft measurements) the IMD of the 10W PA
above 10W is abysmal.

So, no higher power "12 V" PAs please!

Wes N7WS

On 7/31/2016 6:43 PM, Joe Subich, W4TV wrote:

>
>> Then Elecraft can build us a 12 volt version of the KPA500.
>
> Heaven help us, NO! The 12V amplifiers are marginally clean enough
> at 100W. A 500W 12V amplifier is likely to have IMD be much poorer
> than -30 dB PEP. What we really need is a 48V final for the K3/K3S
> (maybe at 200W) so we can see IMD in the -45 dB to -50 dB PEP range
> where it really should be.
>
> It's time to make a stand for cleaner signals ... not signals in the
> same class as the "no name" Italian and Chinese amplifiers.
>
> 73,
>
> ... Joe, W4TV

k6mrmagnet

Re: The amp I would like to see Elecraft build.

In reply to this post by Dan Baker

While making these changes would help, they pale in comparison to a SDR implemented pre-distortion system like Pure Signal. The big advantage will be that the entire transmit chain will be cleaned up as a system, rather than trying to deal with each box separately.

Time to move into the 21st Century.

Ken K6MR

From: Wes Stewart<mailto:[hidden email]>
Sent: Monday, August 1, 2016 21:41
To: [hidden email]<mailto:[hidden email]>
Subject: Re: [Elecraft] The amp I would like to see Elecraft build.

I'm not always on the same page as Joe, but this time I could not agree more.
As someone who has measured the TX IMD of both my kit K3/100 and a factory built
K3S/100 I can attest to this. First of all, they like every other manufacturer
and the ARRL fudge the numbers by 6 dB (in their favor of course) by comparing
one distortion product to the sum of the two tones.

EIMAC and MIL-Specs say, "The standard method of specifying the magnitude of the
distortion products is to specify the reduction in decibels of
one product from one tone of a two-equal-tone signal."

Elecraft isn't to be singled out for this, they are just doing what the ham
industry is doing.

One of several motivations for replacing a perfectly working K3 with the K3S was
the hope that the FET PA would be cleaner than the bipolar PA in the K3. Big
disappointment. One factor is the fact that it's still a nominal "12 V" PA.
Another is that it's still driven by a bipolar "10 W" exciter. If some of you
are using a bare K3/10 and running at greater than 10 W, shame on you. And
shame on Elecraft for letting you do it. Based upon my measurements (which BTW
correlated to 1 dB or less with Elecraft measurements) the IMD of the 10W PA
above 10W is abysmal.

So, no higher power "12 V" PAs please!

Wes N7WS

On 7/31/2016 6:43 PM, Joe Subich, W4TV wrote:

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Joe Subich, W4TV-4

Re: The amp I would like to see Elecraft build.

On 8/2/2016 1:32 AM, Ken K6MR wrote:
> While making these changes would help, they pale in comparison to a
> SDR implemented pre-distortion system like Pure Signal.

SDR based predistortion are most effective if the individual stages
are as clean as possible. That means 24/48V amplifiers for power
levels above 25 to 50 W and 60/100V devices for 500+W amplifiers.

The issue relates to voltage clipping and current saturation. No
amount of predistortion is going to clean up square waves.

73,

... Joe, W4TV

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Ignacy

Re: The amp I would like to see Elecraft build.

12 V PA would open a new type of portable operation.
Call at 500W, conclude the contact at 100W or even 12 W if sufficient.

Power for 500W short term could supplied by a few Li-ion batteries with superconductors. Perhaps 3 lb total.

No more frustration at a campground....

But larger power brings new problems as antenna tuners are larger, and or resonant antennas limit band coverage.

Ignacy, NO9E

briancom

Re: The amp I would like to see Elecraft build.

In reply to this post by Joe Subich, W4TV-4

Of course if one sticks to CW this isn't necessary.

73 de Brian/K3KO

On 8/2/2016 12:45 PM, Joe Subich, W4TV wrote:

>
> On 8/2/2016 1:32 AM, Ken K6MR wrote:
> > While making these changes would help, they pale in comparison to a
> > SDR implemented pre-distortion system like Pure Signal.
>
> SDR based predistortion are most effective if the individual stages
> are as clean as possible. That means 24/48V amplifiers for power
> levels above 25 to 50 W and 60/100V devices for 500+W amplifiers.
>
> The issue relates to voltage clipping and current saturation. No
> amount of predistortion is going to clean up square waves.
>
> 73,
>
> ... Joe, W4TV
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
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Joe Subich, W4TV-4

Re: The amp I would like to see Elecraft build.

Yes but CW (and FSK/RTTY) are dead according to the FCC and ARRL.
Now its all modes that require linear amplification over at
least 2.7 KHz. Better get used to it!

73,

... Joe, W4TV

On 8/2/2016 10:11 AM, brian wrote:

> Of course if one sticks to CW this isn't necessary.
>
> 73 de Brian/K3KO
>
> On 8/2/2016 12:45 PM, Joe Subich, W4TV wrote:
>>
>> On 8/2/2016 1:32 AM, Ken K6MR wrote:
>> > While making these changes would help, they pale in comparison to a
>> > SDR implemented pre-distortion system like Pure Signal.
>>
>> SDR based predistortion are most effective if the individual stages
>> are as clean as possible. That means 24/48V amplifiers for power
>> levels above 25 to 50 W and 60/100V devices for 500+W amplifiers.
>>
>> The issue relates to voltage clipping and current saturation. No
>> amount of predistortion is going to clean up square waves.
>>
>> 73,
>>
>> ... Joe, W4TV
>>
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to [hidden email]
> ______________________________________________________________
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Jim Brown-10

Re: The amp I would like to see Elecraft build.

In reply to this post by briancom

FALSE. CW is 100% modulation of a carrier by a rectangular wave, and
that modulation, like ANY amplitude modulation, produces sidebands,
which will excite distortion in a non-linear amplifier. I don't know
enough about Warren's Pure Signal system to know if it could be used on
CW. IM sidebands can be clearly seen in the display of a CW signal on a P3.

73, Jim K9YC

On Tue,8/2/2016 7:11 AM, brian wrote:

Edward R Cole

Re: The amp I would like to see Elecraft build.

In reply to this post by Dan Baker

I am going to use one of these HP switching 50v PS to supply my
Harris TV amp conversion to 6m. Several others are using this PS for
this application. Use of Ferrite cores filter switching noise:
http://www.bigskyspaces.com/w7gj/HarrisAmps.htm

73, Ed - KL7UW
I paid $30 including shipping for the PS

From: Lewis Phelps <[hidden email]>
To: Elecraft Mailing List <[hidden email]>
Subject: Re: [Elecraft] The amp I would like to see Elecraft build.
Message-ID: <[hidden email]>
Content-Type: text/plain; charset=utf-8

I picked up one of these things at a local surplus store. Noisy as
hell. Not a good idea.

Lew N6LEW

> On Aug 1, 2016, at 7:35 PM, Gary K9GS <[hidden email]> wrote:
>
> Or better yet, do what other SS amp manufacturer's are doing, use
surplus HP Proliant server power supplies? Here's a 3KW one/50V for
$30.00. There are warehouses full of these things available.
snipped-----------

73, Ed - KL7UW
http://www.kl7uw.com
"Kits made by KL7UW"
Dubus Mag business:
[hidden email]

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