Elecraft

KX2/3 Amplifiers

Classic

List

Threaded

6 messages Options

Tom Francis, W1TEF

KX2/3 Amplifiers

Greetings,

I'm looking for a little practical advice about linear amplification for
the KX2/3 (I have both).

Hardrock-50 or KXPA100.

Essentially, it would be used mobile, although taking it out the car and
using it portable is
possible.

So any information from users of these two amps will be greatly
appreciated. Also, as the
Hardrock 50 is a kit, how hard is it to build for something with finger
nephropathy?

Thanks for any info.

Very best regards,

Tom, W1TEF
Lexington, SC

______________________________________________________________
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]

Phil Hystad-3

Re: KX2/3 Amplifiers

I looked into that very question a few months ago (February)…

My comments:

1. I don’t think Hardrock-50 has an auto-tuner so in pricing comparison, compare with
a separate vendors auto-tuner (as good as Elecraft’s) if you are assuming buying the KXPA100 with
auto tuner.

2. Hardrock-50 is half (or, less than half?) the output power of KXPA100 (of course, you know this).

3. Include your own labor time in $ for building the kit? I do this for everything I do to determine
if I want to do myself or pay to have it done. For many of my projects, my time is a lot more valuable than
the cost of somebody else’s time. For example, as a plumber my own labor costs are thousands of dollars
per hour.

Well, these are the three key items that I looked into in comparing leaving out the very likely quality
difference between a full soldering kit built by me versus a kit from Elecraft.

I chose the KXPA100+autotuner as a result of my evaluation.

But, the rest of the story.

I didn’t buy the KXPA100. My reason for 100 watts was to see about getting a 100-watt capable
backup rig and could also be used in portable operations (with adaquate DC power of course).

I made a wild decision. Instead of getting an amp for my KX3. I sold my KX3! In its place I
bought a new Icom IC-7300 and it is light-weight and could be portable (not mobile) as well.

But, I still loved QRP portable ops too so I bought a KX2 to replace my KX3. I also sold other
equipment that was merely collecting dust to also put together the funds to buy the KX2 as
well as a second KAT500 to work with the IC-7300 (since the 7300s internal tuner is not good
enough for all of my antennas in use on all of my bands of interest).

Net cost was minus $130. That is, I had a net gain after buying the IC-7300, the KX2,
and the KAT500 by selling the KX3, and a mobile HF rig, a mobile VHF/UHF rig, and a R-75
receiver.

73, phil, K7PEH

> On May 28, 2017, at 10:50 AM, Tom Francis, W1TEF <[hidden email]> wrote:
>
> Greetings,
>
> I'm looking for a little practical advice about linear amplification for the KX2/3 (I have both).
>
> Hardrock-50 or KXPA100.
>
> Essentially, it would be used mobile, although taking it out the car and using it portable is
> possible.
>
> So any information from users of these two amps will be greatly appreciated. Also, as the
> Hardrock 50 is a kit, how hard is it to build for something with finger nephropathy?
>
> Thanks for any info.
>
> Very best regards,
>
> Tom, W1TEF
> Lexington, SC
>
>
>
>
> ______________________________________________________________
> 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]

______________________________________________________________
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]

Tom Francis, W1TEF

Re: KX2/3 Amplifiers

Phil,

The Hardrock 50 has an atu - I don't know if the toroids are pre-wound
or not - if not, that's an
issue for me.

Actually, I'm kind of in the reverse situation - I want to keep my
KX2/3, but get rid of my FT-450D
- which is a nice radio, but it's bigger than I can use mobile.

All suggestions are welcome and you certainly gave me something to think
about.

Thanks.

Tom, W1TEF
Lexington, SC

On 5/28/2017 2:04 PM, Phil Hystad wrote:

> I looked into that very question a few months ago (February)…
>
> My comments:
>
> 1. I don’t think Hardrock-50 has an auto-tuner so in pricing comparison, compare with
> a separate vendors auto-tuner (as good as Elecraft’s) if you are assuming buying the KXPA100 with
> auto tuner.
>
> 2. Hardrock-50 is half (or, less than half?) the output power of KXPA100 (of course, you know this).
>
> 3. Include your own labor time in $ for building the kit? I do this for everything I do to determine
> if I want to do myself or pay to have it done. For many of my projects, my time is a lot more valuable than
> the cost of somebody else’s time. For example, as a plumber my own labor costs are thousands of dollars
> per hour.
>
> Well, these are the three key items that I looked into in comparing leaving out the very likely quality
> difference between a full soldering kit built by me versus a kit from Elecraft.
>
> I chose the KXPA100+autotuner as a result of my evaluation.
>
> But, the rest of the story.
>
> I didn’t buy the KXPA100. My reason for 100 watts was to see about getting a 100-watt capable
> backup rig and could also be used in portable operations (with adaquate DC power of course).
>
> I made a wild decision. Instead of getting an amp for my KX3. I sold my KX3! In its place I
> bought a new Icom IC-7300 and it is light-weight and could be portable (not mobile) as well.
>
> But, I still loved QRP portable ops too so I bought a KX2 to replace my KX3. I also sold other
> equipment that was merely collecting dust to also put together the funds to buy the KX2 as
> well as a second KAT500 to work with the IC-7300 (since the 7300s internal tuner is not good
> enough for all of my antennas in use on all of my bands of interest).
>
> Net cost was minus $130. That is, I had a net gain after buying the IC-7300, the KX2,
> and the KAT500 by selling the KX3, and a mobile HF rig, a mobile VHF/UHF rig, and a R-75
> receiver.
>
> 73, phil, K7PEH
>
>
>> On May 28, 2017, at 10:50 AM, Tom Francis, W1TEF <[hidden email]> wrote:
>>
>> Greetings,
>>
>> I'm looking for a little practical advice about linear amplification for the KX2/3 (I have both).
>>
>> Hardrock-50 or KXPA100.
>>
>> Essentially, it would be used mobile, although taking it out the car and using it portable is
>> possible.
>>
>> So any information from users of these two amps will be greatly appreciated. Also, as the
>> Hardrock 50 is a kit, how hard is it to build for something with finger nephropathy?
>>
>> Thanks for any info.
>>
>> Very best regards,
>>
>> Tom, W1TEF
>> Lexington, SC
>>
>>
>>
>>
>> ______________________________________________________________
>> 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]
>

Tex

Re: KX2/3 Amplifiers

In reply to this post by Tom Francis, W1TEF

Just ran across this the other day. Anyone know have any experience with this amp?
http://www.ebay.com/itm/Xiegu-XPA125-QRP-ALC-Antenna-Tuner-Function-125W-HF-Ham-Radio-Power-Amplifier-US-/132206081348?hash=item1ec818b544:g:cVQAAOSw9OFZKOkD

73 Tex
ka5y

k6dgw

Re: KX2/3 Amplifiers

It's Chinese, YMMV. The BOGO offer seems strange for ham radio
equipment. Of course, you could always put two into a combiner and get
250 W from a 10 W exciter. [:-) It's in the US, no specslisted,
5W-->125 W is 13.97 dB gain. Doesn't say it runs on nominal 12VDC. I
have no experience and don't intend to get any -- Caveat Emptor.

73,

Fred ("Skip") K6DGW
Sparks NV USA
Washoe County DM09dn

On 5/28/2017 4:15 PM, pkhjr via Elecraft wrote:

> Just ran across this the other day. Anyone know have any experience with
> this amp?
> http://www.ebay.com/itm/Xiegu-XPA125-QRP-ALC-Antenna-Tuner-Function-125W-HF-Ham-Radio-Power-Amplifier-US-/132206081348?hash=item1ec818b544:g:cVQAAOSw9OFZKOkD
>
> 73 Tex
> ka5y
>
>
>
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/KX2-3-Amplifiers-tp7631213p7631225.html
> Sent from the Elecraft mailing list archive at Nabble.com.
> ______________________________________________________________
> 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]
>
> ---
> This email has been checked for viruses by AVG.
> http://www.avg.com
>
>

Ron Manfredi

Re: KX2/3 Amplifiers

In reply to this post by Tex

The writer of the manual has a sense of humor. You can download the
manual, and on the last page of the "Troubleshooting" section the last
problem listed is: "Smoke comes from unit," and the solution, "Replace
the smoke...only kidding, return to dealer."

On 5/28/2017 7:15 PM, pkhjr via Elecraft wrote: