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Low power KX1

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Richard-5

Low power KX1

From: Richard [mailto:[hidden email]]
Sent: Saturday, January 16, 2016 8:50 PM
To: [hidden email]'
Subject: Low power KX1

I am very new to the world of CW. Several months ago I built a KX1. Once I
was able to receive with it, I built the 30-80 band set, and once it was
installed and working, I built the ATU. With the ATU was the first time I
was able to measure power. I am only getting .4W out of internal, and 1W
with a 13 volt power supply. So I did the power modification changing the
resistors, and now I get .6 internal and 2W with 13V.

I could sure use some advice. I do not have a bridge or watt meter. I do
have a good scope Can I measure the signal voltage across 50 ohms?

Thank you in advance.

Richard
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Don Wilhelm-4

Re: Low power KX1

Richard,

Take a careful look at the Low Pass Filter board for the KXB3080
option. Count the turns. Each time the wire passes through the toroid
core is one turn. Make certain you have the correct number of turns.
That LPF is the downfall of many builders. In addition, count the turns
on T1 - the ame thing applies.
Also on the same toroids, be certain the leads were well stripped and
tinned. Look at the solder side. If you can see a ring around the
lead, that lead was not adequately stripped and tinned. You should be
able to see a small bit of tinned lead on the component side of the board.
The LPF board should be *exactly* like that shown in the KXB3080 option
manual illustrations. There is no room for exceptions. Be certain the
green lead of L2 is oriented away from red lead #4.

You will need an external QRP wattmeter to properly calibrate the
wattmeter in the KXAT1, but if you have a good 50 ohm dummy load, you
can use your 'scope to measure the RF voltage across it. Use a 10X
probe on the 'scope and measure the peak to peak voltage. If the dummy
load is sealed, use a T adapter to gain access to the center conductor.
The power is the square of the peak to peak voltage divided by 400.
Derivation of that formula is "left to the student".

73,
Don W3FPR

On 1/16/2016 8:53 PM, Richard wrote:

> From: Richard [mailto:[hidden email]]
> Sent: Saturday, January 16, 2016 8:50 PM
> To: [hidden email]'
> Subject: Low power KX1
>
>
> I am very new to the world of CW. Several months ago I built a KX1. Once I
> was able to receive with it, I built the 30-80 band set, and once it was
> installed and working, I built the ATU. With the ATU was the first time I
> was able to measure power. I am only getting .4W out of internal, and 1W
> with a 13 volt power supply. So I did the power modification changing the
> resistors, and now I get .6 internal and 2W with 13V.
>
> I could sure use some advice. I do not have a bridge or watt meter. I do
> have a good scope Can I measure the signal voltage across 50 ohms?
>
> Thank you in advance.
>
> Richard
> ______________________________________________________________
> 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]
>

Johnny Siu

Low power KX1

In reply to this post by Richard-5

Hello Richard,
Please have a look of my review :

http://www.eham.net/reviews/detail/3586
There are some construction hints.
73
Johnny VR2XMC

寄件人︰ Richard <[hidden email]>
收件人︰ [hidden email]
傳送日期︰ 2016年01月17日 (週日) 9:53 AM
主題︰ [Elecraft] Low power KX1

From: Richard [mailto:[hidden email]]
Sent: Saturday, January 16, 2016 8:50 PM
To: [hidden email]'
Subject: Low power KX1

I am very new to the world of CW. Several months ago I built a KX1. Once I
was able to receive with it, I built the 30-80 band set, and once it was
installed and working, I built the ATU. With the ATU was the first time I
was able to measure power. I am only getting .4W out of internal, and 1W
with a 13 volt power supply. So I did the power modification changing the
resistors, and now I get .6 internal and 2W with 13V.

I could sure use some advice. I do not have a bridge or watt meter. I do
have a good scope Can I measure the signal voltage across 50 ohms?

Thank you in advance.

Richard
______________________________________________________________
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Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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Message delivered to [hidden email]

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Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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Richard-5

Re: Low power KX1

In reply to this post by Don Wilhelm-4

Thank you Don and Ray,

The information proved valuable. Just pushing around on the toroids made a
change so I knew I had a bad connection somewhere. With minor surgery I was
able to reheat the joints, and without the ATU board installed I have 40 to
48 VPP across the bands. I also found that my dummy load was highly
inductive, going over 5 to 1 @ 14Mhz. (using a rigexpert AA-30) I made a new
one that came out at 51ohms resistive.

I think I have something attenuating the signal in the ATU board, as after
it, in both cal and tune modes I have quite a drop in signal.

Results No tuner tuner in cal tuner in tune
3 51v 25 20
7 48v 30 27
10 46v 45 45
14 40v 27 19

In the test modes, I can hear each relay click. And in cal mode they look
like they bypass by shorting the inductors, so I am lost. My electronic
skill is at "I wish I had a lot more" Any and all help is appriciated.

Thank you in advance.
Richard

-----Original Message-----
From: Don Wilhelm [mailto:[hidden email]]
Sent: Sunday, January 17, 2016 2:11 AM
To: [hidden email]; [hidden email]
Subject: Re: [Elecraft] Low power KX1

Richard,

Take a careful look at the Low Pass Filter board for the KXB3080 option.
Count the turns. Each time the wire passes through the toroid core is one
turn. Make certain you have the correct number of turns.
That LPF is the downfall of many builders. In addition, count the turns on
T1 - the ame thing applies.
Also on the same toroids, be certain the leads were well stripped and
tinned. Look at the solder side. If you can see a ring around the lead,
that lead was not adequately stripped and tinned. You should be able to see
a small bit of tinned lead on the component side of the board.
The LPF board should be *exactly* like that shown in the KXB3080 option
manual illustrations. There is no room for exceptions. Be certain the
green lead of L2 is oriented away from red lead #4.

You will need an external QRP wattmeter to properly calibrate the wattmeter
in the KXAT1, but if you have a good 50 ohm dummy load, you can use your
'scope to measure the RF voltage across it. Use a 10X probe on the 'scope
and measure the peak to peak voltage. If the dummy load is sealed, use a T
adapter to gain access to the center conductor.
The power is the square of the peak to peak voltage divided by 400.
Derivation of that formula is "left to the student".

73,
Don W3FPR

On 1/16/2016 8:53 PM, Richard wrote:
> From: Richard [mailto:[hidden email]]
> Sent: Saturday, January 16, 2016 8:50 PM
> To: [hidden email]'
> Subject: Low power KX1
>
>
> I am very new to the world of CW. Several months ago I built a KX1. Once
I

> was able to receive with it, I built the 30-80 band set, and once it was
> installed and working, I built the ATU. With the ATU was the first time I
> was able to measure power. I am only getting .4W out of internal, and 1W
> with a 13 volt power supply. So I did the power modification changing the
> resistors, and now I get .6 internal and 2W with 13V.
>
> I could sure use some advice. I do not have a bridge or watt meter. I do
> have a good scope Can I measure the signal voltage across 50 ohms?
>
> Thank you in advance.
>
> Richard
> ______________________________________________________________
> 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]
>

Johnny Siu

Low power KX1

Hello Richard,
Can you get full power output without the installation of the KXAT1? If yes, they can concentrate your trouble shoot on the KXAT1 only. Below is an extract from my review in eham.

"The tiny LPF1 pcb of KXB3080 is to be situated in the tight space formed between the C46-C49& C54 area of KX1 and R3-R4 & C10 area of KXAT1. Therefore, Page 3 of KXAT1 manual, R3, R4& C10 should be soldered on the component side and cut flush on the other side".

See whether there are component leads from the KXAT1 touch the KX1 components.
73
Johnny VR2XMC 寄件人︰ Richard <[hidden email]>
收件人︰ [hidden email]
傳送日期︰ 2016年01月18日 (週一) 5:11 AM
主題︰ Re: [Elecraft] Low power KX1

Thank you Don and Ray,

The information proved valuable. Just pushing around on the toroids made a
change so I knew I had a bad connection somewhere. With minor surgery I was
able to reheat the joints, and without the ATU board installed I have 40 to
48 VPP across the bands. I also found that my dummy load was highly
inductive, going over 5 to 1 @ 14Mhz. (using a rigexpert AA-30) I made a new
one that came out at 51ohms resistive.

I think I have something attenuating the signal in the ATU board, as after
it, in both cal and tune modes I have quite a drop in signal.

Results No tuner tuner in cal tuner in tune
3 51v 25 20
7 48v 30 27
10 46v 45 45
14 40v 27 19

In the test modes, I can hear each relay click. And in cal mode they look
like they bypass by shorting the inductors, so I am lost. My electronic
skill is at "I wish I had a lot more" Any and all help is appriciated.

Thank you in advance.
Richard

-----Original Message-----
From: Don Wilhelm [mailto:[hidden email]]
Sent: Sunday, January 17, 2016 2:11 AM
To: [hidden email]; [hidden email]
Subject: Re: [Elecraft] Low power KX1

Richard,

Take a careful look at the Low Pass Filter board for the KXB3080 option.
Count the turns. Each time the wire passes through the toroid core is one
turn. Make certain you have the correct number of turns.
That LPF is the downfall of many builders. In addition, count the turns on
T1 - the ame thing applies.
Also on the same toroids, be certain the leads were well stripped and
tinned. Look at the solder side. If you can see a ring around the lead,
that lead was not adequately stripped and tinned. You should be able to see
a small bit of tinned lead on the component side of the board.
The LPF board should be *exactly* like that shown in the KXB3080 option
manual illustrations. There is no room for exceptions. Be certain the
green lead of L2 is oriented away from red lead #4.

You will need an external QRP wattmeter to properly calibrate the wattmeter
in the KXAT1, but if you have a good 50 ohm dummy load, you can use your
'scope to measure the RF voltage across it. Use a 10X probe on the 'scope
and measure the peak to peak voltage. If the dummy load is sealed, use a T
adapter to gain access to the center conductor.
The power is the square of the peak to peak voltage divided by 400.
Derivation of that formula is "left to the student".

73,
Don W3FPR

On 1/16/2016 8:53 PM, Richard wrote:
> From: Richard [mailto:[hidden email]]
> Sent: Saturday, January 16, 2016 8:50 PM
> To: [hidden email]'
> Subject: Low power KX1
>
>
> I am very new to the world of CW. Several months ago I built a KX1. Once
I

______________________________________________________________
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]

Don Wilhelm-4

Re: Low power KX1

In reply to this post by Richard-5

Richard,

The power from the basic KX1 is good - excellent work there.
You apparently have something awry in the KXAT1 (it looks good on 30
meters, but the other bands have problems).

Look the KXAT1 over for soldering problems - solder bridges,
inadequately heated solder connections (reflow with a soldering
temperature of 750 degF), and properly stripped and tinned toroid leads.

Good analysis on the dummy load.

On 1/17/2016 4:11 PM, Richard wrote:

> Thank you Don and Ray,
>
> The information proved valuable. Just pushing around on the toroids made a
> change so I knew I had a bad connection somewhere. With minor surgery I was
> able to reheat the joints, and without the ATU board installed I have 40 to
> 48 VPP across the bands. I also found that my dummy load was highly
> inductive, going over 5 to 1 @ 14Mhz. (using a rigexpert AA-30) I made a new
> one that came out at 51ohms resistive.
>
> I think I have something attenuating the signal in the ATU board, as after
> it, in both cal and tune modes I have quite a drop in signal.
>
> Results No tuner tuner in cal tuner in tune
> 3 51v 25 20
> 7 48v 30 27
> 10 46v 45 45
> 14 40v 27 19
>
> In the test modes, I can hear each relay click. And in cal mode they look
> like they bypass by shorting the inductors, so I am lost. My electronic
> skill is at "I wish I had a lot more" Any and all help is appriciated.
>
> Thank you in advance.
> Richard
>
>
> -----Original Message-----
> From: Don Wilhelm [mailto:[hidden email]]
> Sent: Sunday, January 17, 2016 2:11 AM
> To: [hidden email]; [hidden email]
> Subject: Re: [Elecraft] Low power KX1
>
> Richard,
>
> Take a careful look at the Low Pass Filter board for the KXB3080 option.
> Count the turns. Each time the wire passes through the toroid core is one
> turn. Make certain you have the correct number of turns.
> That LPF is the downfall of many builders. In addition, count the turns on
> T1 - the ame thing applies.
> Also on the same toroids, be certain the leads were well stripped and
> tinned. Look at the solder side. If you can see a ring around the lead,
> that lead was not adequately stripped and tinned. You should be able to see
> a small bit of tinned lead on the component side of the board.
> The LPF board should be *exactly* like that shown in the KXB3080 option
> manual illustrations. There is no room for exceptions. Be certain the
> green lead of L2 is oriented away from red lead #4.
>
> You will need an external QRP wattmeter to properly calibrate the wattmeter
> in the KXAT1, but if you have a good 50 ohm dummy load, you can use your
> 'scope to measure the RF voltage across it. Use a 10X probe on the 'scope
> and measure the peak to peak voltage. If the dummy load is sealed, use a T
> adapter to gain access to the center conductor.
> The power is the square of the peak to peak voltage divided by 400.
> Derivation of that formula is "left to the student".
>
> 73,
> Don W3FPR
>
> On 1/16/2016 8:53 PM, Richard wrote:
>> From: Richard [mailto:[hidden email]]
>> Sent: Saturday, January 16, 2016 8:50 PM
>> To: [hidden email]'
>> Subject: Low power KX1
>>
>>
>> I am very new to the world of CW. Several months ago I built a KX1. Once
> I
>> was able to receive with it, I built the 30-80 band set, and once it was
>> installed and working, I built the ATU. With the ATU was the first time I
>> was able to measure power. I am only getting .4W out of internal, and 1W
>> with a 13 volt power supply. So I did the power modification changing the
>> resistors, and now I get .6 internal and 2W with 13V.
>>
>> I could sure use some advice. I do not have a bridge or watt meter. I do
>> have a good scope Can I measure the signal voltage across 50 ohms?
>>
>> Thank you in advance.
>>
>> Richard
>> ______________________________________________________________
>> 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]
>