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KX3 power reverts from 10W back to 5W

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Arno Dienhart

KX3 power reverts from 10W back to 5W

I would like to come back to this topic with an update after still
experiencing the same issue.

I now use my ZS6BKW with a 1:1 current balun between the twin line and the
coax. I have tried a 70' and a 30' length of coax to the rig. If you think
it will solve the problem, I might even try a 5' length and smolder in the
sun!

My battery shows 11.4 V during transmit on the KX3's PS meter.

SWRs are never higher than 1.3:1 after tuning.

PA temperatures are never very high (sitting in the shade).

I have tried lower W settings, like 8W, which, on some bands, hold for a
while. On other bands, they too revert back to 5W.

So, if this is all normal, I don't understand why the KX3 is rated at 10W.
Or asking in a different way: what needs to be present to keep the
transmitter from reverting down from 10W, and how can I achieve that state
with my setup?

Please keep in mind that I don't have any antenna analyzing instruments
other than what the KX3 provides.

Thank you and 73,

Arno K7RNO

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Don Wilhelm-4

Re: KX3 power reverts from 10W back to 5W

Arno,

Even though the battery voltage measures (as an average) at 11.7 volts
during transmit, my suspicion is that it may be "glitching" for brief
periods below 11 volts and the detection circuit trips forcing the KX3
to low power.

Check all the connections to your power source and make certain they are
"wrench tight" for a starting effort.

The other thing to check are the connections in the antenna system.
Again, a loose connection can cause a 'glitch' to a higher SWR. PL-259
connections that are simply 'finger tightened' are possible suspects,
snug them up a bit with pliers. Unlike BNC, N, TNC, etc, PL-259s depend
on being tight to make the shield connection.

73,
Don W3FPR

On 8/30/2013 1:50 PM, Arno Dienhart wrote:

> I would like to come back to this topic with an update after still
> experiencing the same issue.
>
> I now use my ZS6BKW with a 1:1 current balun between the twin line and the
> coax. I have tried a 70' and a 30' length of coax to the rig. If you think
> it will solve the problem, I might even try a 5' length and smolder in the
> sun!
>
> My battery shows 11.4 V during transmit on the KX3's PS meter.
>
> SWRs are never higher than 1.3:1 after tuning.
>
> PA temperatures are never very high (sitting in the shade).
>
> I have tried lower W settings, like 8W, which, on some bands, hold for a
> while. On other bands, they too revert back to 5W.
>
> So, if this is all normal, I don't understand why the KX3 is rated at 10W.
> Or asking in a different way: what needs to be present to keep the
> transmitter from reverting down from 10W, and how can I achieve that state
> with my setup?
>
> Please keep in mind that I don't have any antenna analyzing instruments
> other than what the KX3 provides.
>
> Thank you and 73,
>
> Arno K7RNO
>
>

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vk2rq

Re: KX3 power reverts from 10W back to 5W

In reply to this post by Arno Dienhart

Hi Arno,

I run a similar setup, ZS6BKW, 1:1 current balun, 100ft RG213 coax, I normally run 10W, and haven't observed problems with the rig switching back to 5W. I do run my rig off a 13.8V 20A supply. If you run at a lower voltage, the rig needs to draw more current to maintain a particular power output. Have you observed the display on the rig at the moment it switches back to 5W? Does it display any warning such as Hi Curr(ent)?

I am a bit concerned about the fact that you report an SWR of 1.3 *after* tuning. I find the SWR is already low on the bands of interest, and after tuning it shows 1.0:1 VSWR. Even on 80m with a native SWR of 7:1 it tunes up to 1.0:1 and happily runs 10W. So, apart from the power supply, I would be a bit concerned that something may be amiss with your antenna system.

73, Matt VK2RQ

On 31/08/2013, at 3:50 AM, "Arno Dienhart" <[hidden email]> wrote:

> I would like to come back to this topic with an update after still
> experiencing the same issue.
>
>
>
> I now use my ZS6BKW with a 1:1 current balun between the twin line and the
> coax. I have tried a 70' and a 30' length of coax to the rig. If you think
> it will solve the problem, I might even try a 5' length and smolder in the
> sun!
>
> My battery shows 11.4 V during transmit on the KX3's PS meter.
>
> SWRs are never higher than 1.3:1 after tuning.
>
> PA temperatures are never very high (sitting in the shade).
>
>
>
> I have tried lower W settings, like 8W, which, on some bands, hold for a
> while. On other bands, they too revert back to 5W.
>
>
>
> So, if this is all normal, I don't understand why the KX3 is rated at 10W.
> Or asking in a different way: what needs to be present to keep the
> transmitter from reverting down from 10W, and how can I achieve that state
> with my setup?
>
>
>
> Please keep in mind that I don't have any antenna analyzing instruments
> other than what the KX3 provides.
>
>
>
> Thank you and 73,
>
> Arno K7RNO
>
> ______________________________________________________________
> 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

Arno Dienhart

Re: KX3 power reverts from 10W back to 5W

Hi Matt,
Maybe I gave a wrong impression with my statement of "SWR never higher than
1.3". Usually, SWR is at 1.0 and only at rare instances do I see 1.3. What I
wanted to express is that SWR should not be the cause of the issue.

I have not observed the display at the very moment of power switching back
and will look for it next time.

73,
Arno K7RNO

-----Original Message-----
From: Matt VK2RQ [mailto:[hidden email]]
Sent: Friday, August 30, 2013 12:32
To: Arno Dienhart
Cc: <[hidden email]>
Subject: Re: [Elecraft] KX3 power reverts from 10W back to 5W

Hi Arno,

I run a similar setup, ZS6BKW, 1:1 current balun, 100ft RG213 coax, I
normally run 10W, and haven't observed problems with the rig switching back
to 5W. I do run my rig off a 13.8V 20A supply. If you run at a lower
voltage, the rig needs to draw more current to maintain a particular power
output. Have you observed the display on the rig at the moment it switches
back to 5W? Does it display any warning such as Hi Curr(ent)?

I am a bit concerned about the fact that you report an SWR of 1.3 *after*
tuning. I find the SWR is already low on the bands of interest, and after
tuning it shows 1.0:1 VSWR. Even on 80m with a native SWR of 7:1 it tunes up
to 1.0:1 and happily runs 10W. So, apart from the power supply, I would be a
bit concerned that something may be amiss with your antenna system.

73, Matt VK2RQ

On 31/08/2013, at 3:50 AM, "Arno Dienhart" <[hidden email]> wrote:

> I would like to come back to this topic with an update after still
> experiencing the same issue.
>
>
>
> I now use my ZS6BKW with a 1:1 current balun between the twin line and
> the coax. I have tried a 70' and a 30' length of coax to the rig. If
> you think it will solve the problem, I might even try a 5' length and
> smolder in the sun!
>
> My battery shows 11.4 V during transmit on the KX3's PS meter.
>
> SWRs are never higher than 1.3:1 after tuning.
>
> PA temperatures are never very high (sitting in the shade).
>
>
>
> I have tried lower W settings, like 8W, which, on some bands, hold for
> a while. On other bands, they too revert back to 5W.
>
>
>
> So, if this is all normal, I don't understand why the KX3 is rated at 10W.
> Or asking in a different way: what needs to be present to keep the
> transmitter from reverting down from 10W, and how can I achieve that
> state with my setup?
>
>
>
> Please keep in mind that I don't have any antenna analyzing
> instruments other than what the KX3 provides.
>
>
>
> Thank you and 73,
>
> Arno K7RNO
>
> ______________________________________________________________
> 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

Richard E Neese

Re: KX3 power reverts from 10W back to 5W

In reply to this post by vk2rq

Here is a few questions.

1) are you running from a external battery or the internal aa batts.
2) have you run a check on the cables to make sure there are no
crimps/bends/breaks in the line with a volt meter ot cable tester or such
3) what is your external power source ? anything under 13.8v like a 12v
laptop power supply will have issues.
4) do you get a high current warning when you transmit before it fails
back to 5w from 10w ?
5) have to proply grounded your station even when portable when possible ?

--
R.Neese
KB3VGW

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Arno Dienhart

Re: KX3 power reverts from 10W back to 5W

In reply to this post by Don Wilhelm-4

Hi Don,

You (and Matt) might have a point with the power connection. I connect to
the battery poles (which have the shape of blades) with copper clips, which
are of rather thin copper sheet, so the contact surface is perhaps too small
and too "loose". I will build a better connection next.

My 259 connectors are well tight, so I don't expect any improvement there
using pliers. However, should the battery connection improvement not yield
the desired result, I will look at the 259s (of which I have four in the
feedlines/balun string, plus two female-to-male adapters). Contingency tests
have not shown any issues, though. But that was just an Ohm meter with 3V
running through.

73,
Arno K7RNO

-----Original Message-----
From: Don Wilhelm [mailto:[hidden email]]
Sent: Friday, August 30, 2013 12:17
To: Arno Dienhart
Cc: [hidden email]
Subject: Re: [Elecraft] KX3 power reverts from 10W back to 5W

Arno,

Even though the battery voltage measures (as an average) at 11.7 volts
during transmit, my suspicion is that it may be "glitching" for brief
periods below 11 volts and the detection circuit trips forcing the KX3 to
low power.

Check all the connections to your power source and make certain they are
"wrench tight" for a starting effort.

The other thing to check are the connections in the antenna system.
Again, a loose connection can cause a 'glitch' to a higher SWR. PL-259
connections that are simply 'finger tightened' are possible suspects, snug
them up a bit with pliers. Unlike BNC, N, TNC, etc, PL-259s depend on being
tight to make the shield connection.

73,
Don W3FPR

On 8/30/2013 1:50 PM, Arno Dienhart wrote:

> I would like to come back to this topic with an update after still
> experiencing the same issue.
>
> I now use my ZS6BKW with a 1:1 current balun between the twin line and
> the coax. I have tried a 70' and a 30' length of coax to the rig. If
> you think it will solve the problem, I might even try a 5' length and
> smolder in the sun!
>
> My battery shows 11.4 V during transmit on the KX3's PS meter.
>
> SWRs are never higher than 1.3:1 after tuning.
>
> PA temperatures are never very high (sitting in the shade).
>
> I have tried lower W settings, like 8W, which, on some bands, hold for
> a while. On other bands, they too revert back to 5W.
>
> So, if this is all normal, I don't understand why the KX3 is rated at 10W.
> Or asking in a different way: what needs to be present to keep the
> transmitter from reverting down from 10W, and how can I achieve that
> state with my setup?
>
> Please keep in mind that I don't have any antenna analyzing
> instruments other than what the KX3 provides.
>
> Thank you and 73,
>
> Arno K7RNO
>
>

Arno Dienhart

Re: KX3 power reverts from 10W back to 5W

In reply to this post by Arno Dienhart

I should have mentioned it again: I am powering from a 12V 17Ah sealed lead
acid battery.

From: KENT TRIMBLE [mailto:[hidden email]]
Sent: Friday, August 30, 2013 12:26
To: Arno Dienhart
Subject: Re: [Elecraft] KX3 power reverts from 10W back to 5W

Are you powering the rig with internal batteries?

K9ZTV

On 8/30/2013 12:50 PM, Arno Dienhart wrote:

I would like to come back to this topic with an update after still
experiencing the same issue.

I now use my ZS6BKW with a 1:1 current balun between the twin line and the
coax. I have tried a 70' and a 30' length of coax to the rig. If you think
it will solve the problem, I might even try a 5' length and smolder in the
sun!

My battery shows 11.4 V during transmit on the KX3's PS meter.

SWRs are never higher than 1.3:1 after tuning.

PA temperatures are never very high (sitting in the shade).

I have tried lower W settings, like 8W, which, on some bands, hold for a
while. On other bands, they too revert back to 5W.

So, if this is all normal, I don't understand why the KX3 is rated at 10W.
Or asking in a different way: what needs to be present to keep the
transmitter from reverting down from 10W, and how can I achieve that state
with my setup?

Please keep in mind that I don't have any antenna analyzing instruments
other than what the KX3 provides.

Thank you and 73,

Arno K7RNO

______________________________________________________________
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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Don Wilhelm-4

Re: KX3 power reverts from 10W back to 5W

In reply to this post by Arno Dienhart

Arno,

Also check the connections to the fuse in your power cord. You *DO*
have it fused do you not?
A fuse near the battery is essential to prevent a shower of molten metal
if there is any fault in the wire or the connected equipment. Any
battery stores a LOT of energy.
The automotive blade type fuses are the best for lower resistance
connections.

73,
Don W3FPR

On 8/30/2013 2:45 PM, Arno Dienhart wrote:

> Hi Don,
>
> You (and Matt) might have a point with the power connection. I connect to
> the battery poles (which have the shape of blades) with copper clips, which
> are of rather thin copper sheet, so the contact surface is perhaps too small
> and too "loose". I will build a better connection next.
>
> My 259 connectors are well tight, so I don't expect any improvement there
> using pliers. However, should the battery connection improvement not yield
> the desired result, I will look at the 259s (of which I have four in the
> feedlines/balun string, plus two female-to-male adapters). Contingency tests
> have not shown any issues, though. But that was just an Ohm meter with 3V
> running through.
>
> 73,
> Arno K7RNO
>

vk2rq

Re: KX3 power reverts from 10W back to 5W

In reply to this post by Arno Dienhart

But why is the SWR varying like that? Is it wind moving the antenna or ladder line around, maybe close to something metal? Is it bad connection? Is the balun saturating or heating up (unlikely at 10W, but then I don't know the details of your balun)?

With the power, it is important to have solid connections and decent gauge wire, and as Don says, a fuse (preferably an automotive style blade fuse) in order to minimise transient voltage drops. Are you running anything else off the battery?

73, Matt VK2RQ

On 31/08/2013, at 4:37 AM, "Arno Dienhart" <[hidden email]> wrote:

> Hi Matt,
> Maybe I gave a wrong impression with my statement of "SWR never higher than
> 1.3". Usually, SWR is at 1.0 and only at rare instances do I see 1.3. What I
> wanted to express is that SWR should not be the cause of the issue.
>
> I have not observed the display at the very moment of power switching back
> and will look for it next time.
>
> 73,
> Arno K7RNO
>
> -----Original Message-----
> From: Matt VK2RQ [mailto:[hidden email]]
> Sent: Friday, August 30, 2013 12:32
> To: Arno Dienhart
> Cc: <[hidden email]>
> Subject: Re: [Elecraft] KX3 power reverts from 10W back to 5W
>
> Hi Arno,
>
> I run a similar setup, ZS6BKW, 1:1 current balun, 100ft RG213 coax, I
> normally run 10W, and haven't observed problems with the rig switching back
> to 5W. I do run my rig off a 13.8V 20A supply. If you run at a lower
> voltage, the rig needs to draw more current to maintain a particular power
> output. Have you observed the display on the rig at the moment it switches
> back to 5W? Does it display any warning such as Hi Curr(ent)?
>
> I am a bit concerned about the fact that you report an SWR of 1.3 *after*
> tuning. I find the SWR is already low on the bands of interest, and after
> tuning it shows 1.0:1 VSWR. Even on 80m with a native SWR of 7:1 it tunes up
> to 1.0:1 and happily runs 10W. So, apart from the power supply, I would be a
> bit concerned that something may be amiss with your antenna system.
>
> 73, Matt VK2RQ
>
> On 31/08/2013, at 3:50 AM, "Arno Dienhart" <[hidden email]> wrote:
>
>> I would like to come back to this topic with an update after still
>> experiencing the same issue.
>>
>>
>>
>> I now use my ZS6BKW with a 1:1 current balun between the twin line and
>> the coax. I have tried a 70' and a 30' length of coax to the rig. If
>> you think it will solve the problem, I might even try a 5' length and
>> smolder in the sun!
>>
>> My battery shows 11.4 V during transmit on the KX3's PS meter.
>>
>> SWRs are never higher than 1.3:1 after tuning.
>>
>> PA temperatures are never very high (sitting in the shade).
>>
>>
>>
>> I have tried lower W settings, like 8W, which, on some bands, hold for
>> a while. On other bands, they too revert back to 5W.
>>
>>
>>
>> So, if this is all normal, I don't understand why the KX3 is rated at 10W.
>> Or asking in a different way: what needs to be present to keep the
>> transmitter from reverting down from 10W, and how can I achieve that
>> state with my setup?
>>
>>
>>
>> Please keep in mind that I don't have any antenna analyzing
>> instruments other than what the KX3 provides.
>>
>>
>>
>> Thank you and 73,
>>
>> Arno K7RNO
>>
>> ______________________________________________________________
>> 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

DL6OAP

Re: KX3 power reverts from 10W back to 5W

In reply to this post by Arno Dienhart

Hi Arno,

If your fully charged batt reads 11.4 V AFTER the KX3 has switched back to 5 W, the voltage reading with 10 W (maybe 50% more current?) will most probably be below 11 V.

I would suggest that you try to gradually increase the output power from 5 Watts and read the voltage and currents from the KX3s meters. This way you will have a measure for the voltage drop and the series resistance in your battery connection and power leads.

Greetings

Ralf

DL6OAP

Am 30.08.2013 um 19:50 schrieb "Arno Dienhart" <[hidden email]>:

Arno Dienhart

Re: KX3 power reverts from 10W back to 5W

All are good suggestions, this and the others. I will try them out and
report back. At this point, my money is on my flimsy clips.

FTR, I do have an inline 7.5A fuse, automotive dual blade type.

To Matt: maybe I am still not communicating clearly. The SWR does not vary
ceteris paribus, only when I go on certain bands (or even only one band). I
didn't make a record of which one and how many but I did tune each band from
160 to 10m (except 60m).

The balun is specified for 200W (LDG). No metal contact along the feedline.
Antenna is 14 gauge, twin is 18 gauge, coax is RG-8x. Nothing else is
running off the battery (a UPS type).

-----Original Message-----
From: Ralf Wilhelm [mailto:[hidden email]]
Sent: Friday, August 30, 2013 13:19
To: Arno Dienhart
Cc: <[hidden email]>
Subject: Re: [Elecraft] KX3 power reverts from 10W back to 5W

Hi Arno,

If your fully charged batt reads 11.4 V AFTER the KX3 has switched back to 5
W, the voltage reading with 10 W (maybe 50% more current?) will most
probably be below 11 V.

I would suggest that you try to gradually increase the output power from 5
Watts and read the voltage and currents from the KX3s meters. This way you
will have a measure for the voltage drop and the series resistance in your
battery connection and power leads.

Greetings

Ralf

DL6OAP

______________________________________________________________
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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