Elecraft

KX3 a teacher for the K3...

Classic

List

Threaded

17 messages Options

Phillip Lontz

KX3 a teacher for the K3...

The KX3 has really helped me learn the ins and outs of the K3.

The K3, I was able to run it and make contacts but it is such a large body of work it has taken me along time to "get it".

The KX3 for some reason really helped to put the K3 into perspective. Really helped... soooo....

Would I buy a KX3 to learn the K3?

Sure...

But then I think the KX3 it so cool, It simply had to be designed and built in Calif. Santa Cruz no less...

Phil
If you don't know what it is... Don't poke it...
Santa Fe

K5SSR
K2 sold (sorry I sold it)
K3 4636
KX1 2664
KX3 1695

______________________________________________________________
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

Jeff Herr

laptop power supply to power KX3

While at work I went through our stock of power supplies for the various
makes of laptops we use.
I found that Toshiba supplies are specified 15v and ranged in current
capability from 2.5 amps and up.

Dell, Lenovo, HP, Acer, Asus all use 19v supplies.

Those Toshiba supplies are very small.

WW6L

______________________________________________________________
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

Fred Townsend

Re: laptop power supply to power KX3

Jeff, caution. Laptop power external supplies are designed to be followed
by precision internal regulators that handle the logic voltages and charging
the battery. The external supplies are not well regulated and can be quite
noisy. They may not be the best supplies for ham rigs.
73
Fred, AE6QL

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Jeff Herr
Sent: Monday, September 17, 2012 6:40 PM
To: 'Elecraft Reflector'
Subject: [Elecraft] laptop power supply to power KX3

While at work I went through our stock of power supplies for the various
makes of laptops we use.
I found that Toshiba supplies are specified 15v and ranged in current
capability from 2.5 amps and up.

Dell, Lenovo, HP, Acer, Asus all use 19v supplies.

Those Toshiba supplies are very small.

WW6L

______________________________________________________________
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

______________________________________________________________
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

Johnny Siu

Re: laptop power supply to power KX3

Yes , correct , laptop supplies are often RF noisy.

Sent from my iPhone 4

"Fred Townsend" <[hidden email]> 於 2012年9月18日下午2:04 寫道：

> Jeff, caution. Laptop power external supplies are designed to be followed
> by precision internal regulators that handle the logic voltages and charging
> the battery. The external supplies are not well regulated and can be quite
> noisy. They may not be the best supplies for ham rigs.
> 73
> Fred, AE6QL
>
> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Jeff Herr
> Sent: Monday, September 17, 2012 6:40 PM
> To: 'Elecraft Reflector'
> Subject: [Elecraft] laptop power supply to power KX3
>
> While at work I went through our stock of power supplies for the various
> makes of laptops we use.
> I found that Toshiba supplies are specified 15v and ranged in current
> capability from 2.5 amps and up.
>
> Dell, Lenovo, HP, Acer, Asus all use 19v supplies.
>
> Those Toshiba supplies are very small.
>
> WW6L
>
>
> ______________________________________________________________
> 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
>
> ______________________________________________________________
> 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

______________________________________________________________
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

Jon Kåre Hellan

Re: laptop power supply to power KX3

On 09/18/2012 01:44 PM, Johnny wrote:
> Yes , correct , laptop supplies are often RF noisy.

Any particular laptop and laptop supply brands favoured by dxpeditions?

Jon LA4RT

>
> Sent from my iPhone 4
>
> "Fred Townsend" <[hidden email]> 於 2012年9月18日下午2:04 寫道：
>
>> Jeff, caution. Laptop power external supplies are designed to be followed
>> by precision internal regulators that handle the logic voltages and charging
>> the battery. The external supplies are not well regulated and can be quite
>> noisy. They may not be the best supplies for ham rigs.
>> 73
>> Fred, AE6QL
>>
>> -----Original Message-----
>> From: [hidden email]
>> [mailto:[hidden email]] On Behalf Of Jeff Herr
>> Sent: Monday, September 17, 2012 6:40 PM
>> To: 'Elecraft Reflector'
>> Subject: [Elecraft] laptop power supply to power KX3
>>
>> While at work I went through our stock of power supplies for the various
>> makes of laptops we use.
>> I found that Toshiba supplies are specified 15v and ranged in current
>> capability from 2.5 amps and up.
>>
>> Dell, Lenovo, HP, Acer, Asus all use 19v supplies.
>>
>> Those Toshiba supplies are very small.
>>
>> WW6L
>>
>>
>> ______________________________________________________________
>> 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
>>
>> ______________________________________________________________
>> 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
> ______________________________________________________________
> 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
>

David Cutter

Re: laptop power supply to power KX3

Thinkpad used on T32C and others.

David
G3UNA

----- Original Message -----
From: "Jon K Hellan" <[hidden email]>
To: <[hidden email]>
Sent: Tuesday, September 18, 2012 11:56 AM
Subject: Re: [Elecraft] laptop power supply to power KX3

> On 09/18/2012 01:44 PM, Johnny wrote:
>> Yes , correct , laptop supplies are often RF noisy.
>
> Any particular laptop and laptop supply brands favoured by dxpeditions?
>
> Jon LA4RT
>
>>
>> Sent from my iPhone 4
>>
>> "Fred Townsend" <[hidden email]> 於 2012年9月18日下午2:04 寫道：
>>
>>
>>> Jeff, caution. Laptop power external supplies are designed to be
>>> followed
>>> by precision internal regulators that handle the logic voltages and
>>> charging
>>> the battery. The external supplies are not well regulated and can be
>>> quite
>>> noisy. They may not be the best supplies for ham rigs.
>>> 73
>>> Fred, AE6QL
>>>
>>> -----Original Message-----
>>> From: [hidden email]
>>> [mailto:[hidden email]] On Behalf Of Jeff Herr
>>> Sent: Monday, September 17, 2012 6:40 PM
>>> To: 'Elecraft Reflector'
>>> Subject: [Elecraft] laptop power supply to power KX3
>>>
>>> While at work I went through our stock of power supplies for the various
>>> makes of laptops we use.
>>> I found that Toshiba supplies are specified 15v and ranged in current
>>> capability from 2.5 amps and up.
>>>
>>> Dell, Lenovo, HP, Acer, Asus all use 19v supplies.
>>>
>>> Those Toshiba supplies are very small.
>>>
>>> WW6L
>>>
>>>
>>> ______________________________________________________________
>>> 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
>>>
>>> ______________________________________________________________
>>> 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
>> ______________________________________________________________
>> 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
>>
>
> ______________________________________________________________
> 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

Bill Tubbs, WK6A

Re: laptop power supply to power KX3

In reply to this post by Johnny Siu

After sending my note about using the little MFJ power supply at 2.89 amps, I realized that it works fine on my FT-817D at 5 watts but would obviously be taxed at the full 12 watts of the KX3. So fuggetabowdit.

Now I'M looking for a sufficient supply for the KX3 ;-)

Bill
WK6A

Sent from my iPhone

On Sep 18, 2012, at 4:44 AM, Johnny <[hidden email]> wrote:

> Yes , correct , laptop supplies are often RF noisy.
>
> Sent from my iPhone 4
>
> "Fred Townsend" <[hidden email]> 於 2012年9月18日下午2:04 寫道：
>
>> Jeff, caution. Laptop power external supplies are designed to be followed
>> by precision internal regulators that handle the logic voltages and charging
>> the battery. The external supplies are not well regulated and can be quite
>> noisy. They may not be the best supplies for ham rigs.
>> 73
>> Fred, AE6QL
>>
>> -----Original Message-----
>> From: [hidden email]
>> [mailto:[hidden email]] On Behalf Of Jeff Herr
>> Sent: Monday, September 17, 2012 6:40 PM
>> To: 'Elecraft Reflector'
>> Subject: [Elecraft] laptop power supply to power KX3
>>
>> While at work I went through our stock of power supplies for the various
>> makes of laptops we use.
>> I found that Toshiba supplies are specified 15v and ranged in current
>> capability from 2.5 amps and up.
>>
>> Dell, Lenovo, HP, Acer, Asus all use 19v supplies.
>>
>> Those Toshiba supplies are very small.
>>
>> WW6L
>>
>>
>> ______________________________________________________________
>> 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
>>
>> ______________________________________________________________
>> 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
> ______________________________________________________________
> 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

Don Wilhelm-4

Re: laptop power supply to power KX3

Bill,

I would suggest an Astron 20 amp supply (or even the 35 amp linear).
Yes, it is overkill for the 12 watt KX3, but that is no problem, the
current will not exceed what the connected device (the KX3) needs even
though the supply is capable of much more current. When you also have
the KXPA3, you will need that extra current. You also have other 12
volt powered devices around the shack, so the extra current rating will
help with powering those devices.

For those who want to homebrew for the basic KX3, I suggest you look at
the article in QST from November 1993 page 27 for a 5 amp regulated 13.8
volt 5 amp power supply with crowbar overvoltage protection. We are
hams, so think "build your own" It is a good philisophy/

73,
Don W3FPR

On 9/18/2012 4:53 PM, Bill Tubbs wrote:

> After sending my note about using the little MFJ power supply at 2.89 amps, I realized that it works fine on my FT-817D at 5 watts but would obviously be taxed at the full 12 watts of the KX3. So fuggetabowdit.
>
> Now I'M looking for a sufficient supply for the KX3 ;-)
>
> Bill
> WK6A
>
> Sent from my iPhone
>
> On Sep 18, 2012, at 4:44 AM, Johnny <[hidden email]> wrote:
>
>> Yes , correct , laptop supplies are often RF noisy.
>>
>> Sent from my iPhone 4
>>
>> "Fred Townsend" <[hidden email]> 於 2012年9月18日下午2:04 寫道：
>>
>>> Jeff, caution. Laptop power external supplies are designed to be followed
>>> by precision internal regulators that handle the logic voltages and charging
>>> the battery. The external supplies are not well regulated and can be quite
>>> noisy. They may not be the best supplies for ham rigs.
>>> 73
>>> Fred, AE6QL
>>>
>>> -----Original Message-----
>>> From: [hidden email]
>>> [mailto:[hidden email]] On Behalf Of Jeff Herr
>>> Sent: Monday, September 17, 2012 6:40 PM
>>> To: 'Elecraft Reflector'
>>> Subject: [Elecraft] laptop power supply to power KX3
>>>
>>> While at work I went through our stock of power supplies for the various
>>> makes of laptops we use.
>>> I found that Toshiba supplies are specified 15v and ranged in current
>>> capability from 2.5 amps and up.
>>>
>>> Dell, Lenovo, HP, Acer, Asus all use 19v supplies.
>>>
>>> Those Toshiba supplies are very small.
>>>
>>> WW6L
>>>
>>>
>>> ______________________________________________________________
>>> 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
>>>
>>> ______________________________________________________________
>>> 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
>> ______________________________________________________________
>> 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
> ______________________________________________________________
> 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

Bill Tubbs, WK6A

Re: laptop power supply to power KX3

I actually have a 20-amp Astron, as well as a 20-amp Icom supply, but I was hoping for something in the middle. If I were just going to consider using only the KX3 i suppose a 6-7 Amp supply would do the trick, and I would think it might be no bigger than the KX3 itself, no?

Bill
WK6A

Sent from my iPhone

On Sep 18, 2012, at 2:16 PM, Don Wilhelm <[hidden email]> wrote:

> Bill,
>
> I would suggest an Astron 20 amp supply (or even the 35 amp linear). Yes, it is overkill for the 12 watt KX3, but that is no problem, the current will not exceed what the connected device (the KX3) needs even though the supply is capable of much more current. When you also have the KXPA3, you will need that extra current. You also have other 12 volt powered devices around the shack, so the extra current rating will help with powering those devices.
>
> For those who want to homebrew for the basic KX3, I suggest you look at the article in QST from November 1993 page 27 for a 5 amp regulated 13.8 volt 5 amp power supply with crowbar overvoltage protection. We are hams, so think "build your own" It is a good philisophy/
>
> 73,
> Don W3FPR
>
> On 9/18/2012 4:53 PM, Bill Tubbs wrote:
>> After sending my note about using the little MFJ power supply at 2.89 amps, I realized that it works fine on my FT-817D at 5 watts but would obviously be taxed at the full 12 watts of the KX3. So fuggetabowdit.
>>
>> Now I'M looking for a sufficient supply for the KX3 ;-)
>>
>> Bill
>> WK6A
>>
>> Sent from my iPhone
>>
>> On Sep 18, 2012, at 4:44 AM, Johnny <[hidden email]> wrote:
>>
>>> Yes , correct , laptop supplies are often RF noisy.
>>>
>>> Sent from my iPhone 4
>>>
>>> "Fred Townsend" <[hidden email]> 於 2012年9月18日下午2:04 寫道：
>>>
>>>> Jeff, caution. Laptop power external supplies are designed to be followed
>>>> by precision internal regulators that handle the logic voltages and charging
>>>> the battery. The external supplies are not well regulated and can be quite
>>>> noisy. They may not be the best supplies for ham rigs.
>>>> 73
>>>> Fred, AE6QL
>>>>
>>>> -----Original Message-----
>>>> From: [hidden email]
>>>> [mailto:[hidden email]] On Behalf Of Jeff Herr
>>>> Sent: Monday, September 17, 2012 6:40 PM
>>>> To: 'Elecraft Reflector'
>>>> Subject: [Elecraft] laptop power supply to power KX3
>>>>
>>>> While at work I went through our stock of power supplies for the various
>>>> makes of laptops we use.
>>>> I found that Toshiba supplies are specified 15v and ranged in current
>>>> capability from 2.5 amps and up.
>>>>
>>>> Dell, Lenovo, HP, Acer, Asus all use 19v supplies.
>>>>
>>>> Those Toshiba supplies are very small.
>>>>
>>>> WW6L
>>>>
>>>>
>>>> ______________________________________________________________
>>>> 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
>>>>
>>>> ______________________________________________________________
>>>> 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
>>> ______________________________________________________________
>>> 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
>> ______________________________________________________________
>> 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
>

Don Wilhelm-4

Re: laptop power supply to power KX3

Bill,

If it sits on the floor, what is the problem. No meters in your face,
just good DC power provided to the rigrunner. The fuse sets the current
supplied to the transceiver. The KX3 will only draw 3 amps on transmit
at full power. The maximum current available from the power supply has
no meaning other that the requirements of the load cannot exceed the
power supply ratings. In other words, one cannot power a 100 watt
amplifier from a 6 ampere power supply.

I detect that there are many monitoring this thread who do not
understand the voltage, current. power relationship as it relates to
DC. I do not want to enlighten all, but some of the questions have gone
below the level that all radio amateurs should understand from basic
principles of Ohms Law - some of the most fundamental equations relating
voltage, current, and power. If there is not a basic understanding of
those parameters, there is a great communications loss. I am sorry, but
I cannot "spoon feed" those who do not have a grasp of those basic
electrical parameters. If it was not on your amateur radio exam, then
you can find it in the ARRL Handbook Electrical Laws and Circuits chapter.
It is simple - voltage equals current times resistance, Power equals
voltage times current - fundamental formulas, but I feel that many hams
do not have any concept of those parameters - this is basic, entry level
stuff.

73,
Don W3FPR

On 9/18/2012 6:40 PM, Bill Tubbs wrote:

> I actually have a 20-amp Astron, as well as a 20-amp Icom supply, but I was hoping for something in the middle. If I were just going to consider using only the KX3 i suppose a 6-7 Amp supply would do the trick, and I would think it might be no bigger than the KX3 itself, no?
>
> Bill
> WK6A
>
> Sent from my iPhone
>
> On Sep 18, 2012, at 2:16 PM, Don Wilhelm <[hidden email]> wrote:
>
>> Bill,
>>
>> I would suggest an Astron 20 amp supply (or even the 35 amp linear). Yes, it is overkill for the 12 watt KX3, but that is no problem, the current will not exceed what the connected device (the KX3) needs even though the supply is capable of much more current. When you also have the KXPA3, you will need that extra current. You also have other 12 volt powered devices around the shack, so the extra current rating will help with powering those devices.
>>
>> For those who want to homebrew for the basic KX3, I suggest you look at the article in QST from November 1993 page 27 for a 5 amp regulated 13.8 volt 5 amp power supply with crowbar overvoltage protection. We are hams, so think "build your own" It is a good philisophy/
>>
>> 73,
>> Don W3FPR
>>
>> On 9/18/2012 4:53 PM, Bill Tubbs wrote:
>>> After sending my note about using the little MFJ power supply at 2.89 amps, I realized that it works fine on my FT-817D at 5 watts but would obviously be taxed at the full 12 watts of the KX3. So fuggetabowdit.
>>>
>>> Now I'M looking for a sufficient supply for the KX3 ;-)
>>>
>>> Bill
>>> WK6A
>>>
>>> Sent from my iPhone
>>>
>>> On Sep 18, 2012, at 4:44 AM, Johnny <[hidden email]> wrote:
>>>
>>>> Yes , correct , laptop supplies are often RF noisy.
>>>>
>>>> Sent from my iPhone 4
>>>>
>>>> "Fred Townsend" <[hidden email]> 於 2012年9月18日下午2:04 寫道：
>>>>
>>>>> Jeff, caution. Laptop power external supplies are designed to be followed
>>>>> by precision internal regulators that handle the logic voltages and charging
>>>>> the battery. The external supplies are not well regulated and can be quite
>>>>> noisy. They may not be the best supplies for ham rigs.
>>>>> 73
>>>>> Fred, AE6QL
>>>>>
>>>>> -----Original Message-----
>>>>> From: [hidden email]
>>>>> [mailto:[hidden email]] On Behalf Of Jeff Herr
>>>>> Sent: Monday, September 17, 2012 6:40 PM
>>>>> To: 'Elecraft Reflector'
>>>>> Subject: [Elecraft] laptop power supply to power KX3
>>>>>
>>>>> While at work I went through our stock of power supplies for the various
>>>>> makes of laptops we use.
>>>>> I found that Toshiba supplies are specified 15v and ranged in current
>>>>> capability from 2.5 amps and up.
>>>>>
>>>>> Dell, Lenovo, HP, Acer, Asus all use 19v supplies.
>>>>>
>>>>> Those Toshiba supplies are very small.
>>>>>
>>>>> WW6L
>>>>>
>>>>>
>>>>> ______________________________________________________________
>>>>> 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
>>>>>
>>>>> ______________________________________________________________
>>>>> 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
>>>> ______________________________________________________________
>>>> 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
>>> ______________________________________________________________
>>> 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
> ______________________________________________________________
> 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

Phil Salas

Re: laptop power supply to power KX3

In reply to this post by Bill Tubbs, WK6A

“After sending my note about using the little MFJ power supply at 2.89 amps,
I realized that it works fine on my FT-817D at 5 watts but would obviously
be taxed at the full 12 watts of the KX3. So fuggetabowdit.”

The MFJ supply will power the KX3 just fine at 10 watts. The KX3 draws
about 2-amps at 10 watts. I used the little MFJ supply (which is rated at
2.8 amps) to power my IC-703 which also put out 10 watts at about 2-amps.

Phil – AD5X

______________________________________________________________
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

KU7Y

Re: laptop power supply to power KX3

When in AZ, I run the KX3 with a 3 Amp RS supply.

I have seen no problems with it.

At one time I had 4 or 5 of these little supplies but down to 2 or 3
now..... gave the others away!

I bought them several years ago and have used them for many items, including
my NorCal 40a, a couple of the MFJ CW rigs and etc.

Like the old Timex commercial, they just keep on ticking!

OK, back in my hole,

Ron, KU7Y
SOWP 5545M
Arizona Outlaws Contest Club
Brenda, AZ (Winter)
Caldwell, ID (Summer)
[hidden email]
http://www.hatpinsandmore.com
KX3 #0062

______________________________________________________________
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

David Moorman

Re: laptop power supply to power KX3

In reply to this post by Bill Tubbs, WK6A

The specs say the KX3 current draw is typically one to two amps when transmitting, so your 2.89 amp PS should do fine.

Dave, K9SW

On Sep 18, 2012, at 3:53 PM, Bill Tubbs <[hidden email]> wrote:

Matt Maguire

Re: laptop power supply to power KX3

In reply to this post by Don Wilhelm-4

On 19/09/2012, at 9:08 AM, Don Wilhelm <[hidden email]> wrote:
> I detect that there are many monitoring this thread who do not
> understand the voltage, current. power relationship as it relates to
> DC.

Perhaps these links will help those people:
http://gsuryalss.wordpress.com/tag/ohm-amp-volt/
http://xkcd.com/643/

73, Matt VK2ACL

______________________________________________________________
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

Bill Tubbs, WK6A

Re: laptop power supply to power KX3

In reply to this post by Phil Salas

Yeah, I spoke before doing the math. As Don said, the math is simple. P=EI. Or, I=P/E. So, I don't know what the KX3 input is but if we say it's 20 watts, 20/12=1.67 amps. Clearly the MFJ should handle the KX3 at full power, at least for non-data modes. Thanks for shaking my cobwebs loose!

Bill
WK6A

Sent from my iPhone

On Sep 18, 2012, at 5:06 PM, "Phil&Debbie" <[hidden email]> wrote:

> “After sending my note about using the little MFJ power supply at 2.89 amps,
> I realized that it works fine on my FT-817D at 5 watts but would obviously
> be taxed at the full 12 watts of the KX3. So fuggetabowdit.”
>
> The MFJ supply will power the KX3 just fine at 10 watts. The KX3 draws
> about 2-amps at 10 watts. I used the little MFJ supply (which is rated at
> 2.8 amps) to power my IC-703 which also put out 10 watts at about 2-amps.
>
> Phil – AD5X
>
> ______________________________________________________________
> 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

David Cutter

Re: laptop power supply to power KX3

In reply to this post by Phil Salas

To optimise the size of the supply to the load, one could examine the rms
current draw v peak current draw. It might only be a case of fitting a
large capacitor close to the radio (perhaps in a tiny box or heat shrunk
"speed bump" in the cable) to supply those current peaks from a very small
supply. This technique is used in some supplies that use super-capacitors
and a small switchmode for 100W transceivers. This has the advantage of
creating much lower switching noise which is easier/smaller/cheaper to
filter out.

David
G3UNA

______________________________________________________________
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

Bob Nielsen-3

Re: laptop power supply to power KX3

In reply to this post by Bill Tubbs, WK6A

I have used the same supply with my K2 at 10 watts with no issues.

Bob N7XY

On Sep 18, 2012, at 10:26 PM, Bill Tubbs <[hidden email]> wrote:

> Yeah, I spoke before doing the math. As Don said, the math is simple. P=EI. Or, I=P/E. So, I don't know what the KX3 input is but if we say it's 20 watts, 20/12=1.67 amps. Clearly the MFJ should handle the KX3 at full power, at least for non-data modes. Thanks for shaking my cobwebs loose!
>
> Bill
> WK6A
>
> Sent from my iPhone
>
> On Sep 18, 2012, at 5:06 PM, "Phil&Debbie" <[hidden email]> wrote:
>
>> “After sending my note about using the little MFJ power supply at 2.89 amps,
>> I realized that it works fine on my FT-817D at 5 watts but would obviously
>> be taxed at the full 12 watts of the KX3. So fuggetabowdit.”
>>
>> The MFJ supply will power the KX3 just fine at 10 watts. The KX3 draws
>> about 2-amps at 10 watts. I used the little MFJ supply (which is rated at
>> 2.8 amps) to power my IC-703 which also put out 10 watts at about 2-amps.
>>
>> Phil – AD5X
>>
>> ______________________________________________________________
>> 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
>
> ______________________________________________________________
> 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