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KX3 Intermittent changes in audio gain

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Kevin Luxford

KX3 Intermittent changes in audio gain

Hi Guys,
My KX3 has just developed an apparent fault - the audio level changes
abruptly every few seconds from a comfortable listening level to quiet,
but still audible.

I am using my Proset headphones.

Any thoughts on where I should start looking? I am nervous about poking
around surface mount circuits!

vy 73
Kevin
VK3DAP / ZL2DAP
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Keith Heimbold

Re: KX3 Intermittent changes in audio gain

I had this happen to me during mobile operations and not sure why either. Signals dropped right out and then when I turned off the radio for a few minutes and when i turned on the KX3 it went back to where it was prior and remained that way.

I will keep an eye on it to see if it happens again.

Keith
AG6AZ

Sent from my iPhone please excuse typos

On Sep 20, 2012, at 7:43 PM, "Kevin Luxford" <[hidden email]> wrote:

> Hi Guys,
> My KX3 has just developed an apparent fault - the audio level changes
> abruptly every few seconds from a comfortable listening level to quiet,
> but still audible.
>
> I am using my Proset headphones.
>
> Any thoughts on where I should start looking? I am nervous about poking
> around surface mount circuits!
>
> vy 73
> Kevin
> VK3DAP / ZL2DAP
> ______________________________________________________________
> 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

Matt Zilmer

Re: KX3 Intermittent changes in audio gain

The KX3 probably detected a HI CUR condition. This can happen because
of high (or low) PS voltage due to automotive electrical fluctuations.
Sometimes this can happen because of ground current with the antenna
connected, so check this for a positive correlation.

You should not see HI CUR while on the KX3's internal batteries. This
proves the automotive supply is caused it.

When the KX3 sees HI CUR (usually something higher than 300 mA on RX),
it will flash that HI CUR message on VFO A. If the condition
persists, it will drop the AF gain to some predetermined value. If
the condition continues beyond that point, the KX3 will shut itself
off to protect itself. In my own case, both the AF gain and
self-shutdown events were happening. HI CUR is preventable in a
mobile setting - see below.

I produced a pretty good document on KX3 mobile ops, which I'm about
to add to. It's posted on the Elecraft web site at
http://www.elecraft.com/K2_Manual_Download_Page.htm#kx3_mobile.

Keith, I saw that same type of problem while mobile with KX3 #6 right
up until I installed a DC-DC converter. See the doc for details of
all that.

73,
matt W6NIA
KX3 #6, K3 #24, etc.

On Fri, 21 Sep 2012 05:45:18 -0700, you wrote:

>I had this happen to me during mobile operations and not sure why either. Signals dropped right out and then when I turned off the radio for a few minutes and when i turned on the KX3 it went back to where it was prior and remained that way.
>
>I will keep an eye on it to see if it happens again.
>
>Keith
>AG6AZ
>
>Sent from my iPhone please excuse typos
>
>On Sep 20, 2012, at 7:43 PM, "Kevin Luxford" <[hidden email]> wrote:
>
>> Hi Guys,
>> My KX3 has just developed an apparent fault - the audio level changes
>> abruptly every few seconds from a comfortable listening level to quiet,
>> but still audible.
>>
>> I am using my Proset headphones.
>>
>> Any thoughts on where I should start looking? I am nervous about poking
>> around surface mount circuits!
>>
>> vy 73
>> Kevin
>> VK3DAP / ZL2DAP
>> ______________________________________________________________
>> 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

Keith Heimbold

Re: KX3 Intermittent changes in audio gain

Matt

That's exactly what has happened I saw the high current flash I didn't see it before because I was driving but I just saw it now so I think there's a positive correlation.

Thank you very much for the insight!

Keith
AG6AZ

Sent from my iPhone please excuse typos

On Sep 21, 2012, at 7:18 AM, "Matt Zilmer" <[hidden email]> wrote:

> The KX3 probably detected a HI CUR condition. This can happen because
> of high (or low) PS voltage due to automotive electrical fluctuations.
> Sometimes this can happen because of ground current with the antenna
> connected, so check this for a positive correlation.
>
> You should not see HI CUR while on the KX3's internal batteries. This
> proves the automotive supply is caused it.
>
> When the KX3 sees HI CUR (usually something higher than 300 mA on RX),
> it will flash that HI CUR message on VFO A. If the condition
> persists, it will drop the AF gain to some predetermined value. If
> the condition continues beyond that point, the KX3 will shut itself
> off to protect itself. In my own case, both the AF gain and
> self-shutdown events were happening. HI CUR is preventable in a
> mobile setting - see below.
>
> I produced a pretty good document on KX3 mobile ops, which I'm about
> to add to. It's posted on the Elecraft web site at
> http://www.elecraft.com/K2_Manual_Download_Page.htm#kx3_mobile.
>
> Keith, I saw that same type of problem while mobile with KX3 #6 right
> up until I installed a DC-DC converter. See the doc for details of
> all that.
>
> 73,
> matt W6NIA
> KX3 #6, K3 #24, etc.
>
> On Fri, 21 Sep 2012 05:45:18 -0700, you wrote:
>
>> I had this happen to me during mobile operations and not sure why either. Signals dropped right out and then when I turned off the radio for a few minutes and when i turned on the KX3 it went back to where it was prior and remained that way.
>>
>> I will keep an eye on it to see if it happens again.
>>
>> Keith
>> AG6AZ
>>
>> Sent from my iPhone please excuse typos
>>
>> On Sep 20, 2012, at 7:43 PM, "Kevin Luxford" <[hidden email]> wrote:
>>
>>> Hi Guys,
>>> My KX3 has just developed an apparent fault - the audio level changes
>>> abruptly every few seconds from a comfortable listening level to quiet,
>>> but still audible.
>>>
>>> I am using my Proset headphones.
>>>
>>> Any thoughts on where I should start looking? I am nervous about poking
>>> around surface mount circuits!
>>>
>>> vy 73
>>> Kevin
>>> VK3DAP / ZL2DAP
>>> ______________________________________________________________
>>> 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

Matt Zilmer

Re: KX3 Intermittent changes in audio gain

Yup. All you have to do is stabilize the power supply at the K3. I
recommend a DC-DC converter for this.

73,
matt W6NIA

On Fri, 21 Sep 2012 14:22:26 -0700, you wrote:

>Matt
>
>That's exactly what has happened I saw the high current flash I didn't see it before because I was driving but I just saw it now so I think there's a positive correlation.
>
>Thank you very much for the insight!
>
>Keith
>AG6AZ
>
>Sent from my iPhone please excuse typos
>
>On Sep 21, 2012, at 7:18 AM, "Matt Zilmer" <[hidden email]> wrote:
>
>> The KX3 probably detected a HI CUR condition. This can happen because
>> of high (or low) PS voltage due to automotive electrical fluctuations.
>> Sometimes this can happen because of ground current with the antenna
>> connected, so check this for a positive correlation.
>>
>> You should not see HI CUR while on the KX3's internal batteries. This
>> proves the automotive supply is caused it.
>>
>> When the KX3 sees HI CUR (usually something higher than 300 mA on RX),
>> it will flash that HI CUR message on VFO A. If the condition
>> persists, it will drop the AF gain to some predetermined value. If
>> the condition continues beyond that point, the KX3 will shut itself
>> off to protect itself. In my own case, both the AF gain and
>> self-shutdown events were happening. HI CUR is preventable in a
>> mobile setting - see below.
>>
>> I produced a pretty good document on KX3 mobile ops, which I'm about
>> to add to. It's posted on the Elecraft web site at
>> http://www.elecraft.com/K2_Manual_Download_Page.htm#kx3_mobile.
>>
>> Keith, I saw that same type of problem while mobile with KX3 #6 right
>> up until I installed a DC-DC converter. See the doc for details of
>> all that.
>>
>> 73,
>> matt W6NIA
>> KX3 #6, K3 #24, etc.
>>
>> On Fri, 21 Sep 2012 05:45:18 -0700, you wrote:
>>
>>> I had this happen to me during mobile operations and not sure why either. Signals dropped right out and then when I turned off the radio for a few minutes and when i turned on the KX3 it went back to where it was prior and remained that way.
>>>
>>> I will keep an eye on it to see if it happens again.
>>>
>>> Keith
>>> AG6AZ
>>>
>>> Sent from my iPhone please excuse typos
>>>
>>> On Sep 20, 2012, at 7:43 PM, "Kevin Luxford" <[hidden email]> wrote:
>>>
>>>> Hi Guys,
>>>> My KX3 has just developed an apparent fault - the audio level changes
>>>> abruptly every few seconds from a comfortable listening level to quiet,
>>>> but still audible.
>>>>
>>>> I am using my Proset headphones.
>>>>
>>>> Any thoughts on where I should start looking? I am nervous about poking
>>>> around surface mount circuits!
>>>>
>>>> vy 73
>>>> Kevin
>>>> VK3DAP / ZL2DAP
>>>> ______________________________________________________________
>>>> 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

Keith Heimbold

Re: KX3 Intermittent changes in audio gain

Any recommendation or specific brand or place to purchase one for a KX3. Appreciate the sharing of knowledge.

Thanks,

Keith
AG6AZ

Sent from my iPhone please excuse typos

On Sep 21, 2012, at 4:19 PM, "Matt Zilmer" <[hidden email]> wrote:

> Yup. All you have to do is stabilize the power supply at the K3. I
> recommend a DC-DC converter for this.
>
> 73,
> matt W6NIA
>
> On Fri, 21 Sep 2012 14:22:26 -0700, you wrote:
>
>> Matt
>>
>> That's exactly what has happened I saw the high current flash I didn't see it before because I was driving but I just saw it now so I think there's a positive correlation.
>>
>> Thank you very much for the insight!
>>
>> Keith
>> AG6AZ
>>
>> Sent from my iPhone please excuse typos
>>
>> On Sep 21, 2012, at 7:18 AM, "Matt Zilmer" <[hidden email]> wrote:
>>
>>> The KX3 probably detected a HI CUR condition. This can happen because
>>> of high (or low) PS voltage due to automotive electrical fluctuations.
>>> Sometimes this can happen because of ground current with the antenna
>>> connected, so check this for a positive correlation.
>>>
>>> You should not see HI CUR while on the KX3's internal batteries. This
>>> proves the automotive supply is caused it.
>>>
>>> When the KX3 sees HI CUR (usually something higher than 300 mA on RX),
>>> it will flash that HI CUR message on VFO A. If the condition
>>> persists, it will drop the AF gain to some predetermined value. If
>>> the condition continues beyond that point, the KX3 will shut itself
>>> off to protect itself. In my own case, both the AF gain and
>>> self-shutdown events were happening. HI CUR is preventable in a
>>> mobile setting - see below.
>>>
>>> I produced a pretty good document on KX3 mobile ops, which I'm about
>>> to add to. It's posted on the Elecraft web site at
>>> http://www.elecraft.com/K2_Manual_Download_Page.htm#kx3_mobile.
>>>
>>> Keith, I saw that same type of problem while mobile with KX3 #6 right
>>> up until I installed a DC-DC converter. See the doc for details of
>>> all that.
>>>
>>> 73,
>>> matt W6NIA
>>> KX3 #6, K3 #24, etc.
>>>
>>> On Fri, 21 Sep 2012 05:45:18 -0700, you wrote:
>>>
>>>> I had this happen to me during mobile operations and not sure why either. Signals dropped right out and then when I turned off the radio for a few minutes and when i turned on the KX3 it went back to where it was prior and remained that way.
>>>>
>>>> I will keep an eye on it to see if it happens again.
>>>>
>>>> Keith
>>>> AG6AZ
>>>>
>>>> Sent from my iPhone please excuse typos
>>>>
>>>> On Sep 20, 2012, at 7:43 PM, "Kevin Luxford" <[hidden email]> wrote:
>>>>
>>>>> Hi Guys,
>>>>> My KX3 has just developed an apparent fault - the audio level changes
>>>>> abruptly every few seconds from a comfortable listening level to quiet,
>>>>> but still audible.
>>>>>
>>>>> I am using my Proset headphones.
>>>>>
>>>>> Any thoughts on where I should start looking? I am nervous about poking
>>>>> around surface mount circuits!
>>>>>
>>>>> vy 73
>>>>> Kevin
>>>>> VK3DAP / ZL2DAP
>>>>> ______________________________________________________________
>>>>> 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

Matt Zilmer

Re: KX3 Intermittent changes in audio gain

There is one recommended in that doc I authored - the one posted on
the Elecraft manuals section.

73,
matt

On Fri, 21 Sep 2012 16:24:43 -0700, you wrote:

>Any recommendation or specific brand or place to purchase one for a KX3. Appreciate the sharing of knowledge.
>
>Thanks,
>
>Keith
>AG6AZ
>
>Sent from my iPhone please excuse typos
>
>On Sep 21, 2012, at 4:19 PM, "Matt Zilmer" <[hidden email]> wrote:
>
>> Yup. All you have to do is stabilize the power supply at the K3. I
>> recommend a DC-DC converter for this.
>>
>> 73,
>> matt W6NIA
>>
>> On Fri, 21 Sep 2012 14:22:26 -0700, you wrote:
>>
>>> Matt
>>>
>>> That's exactly what has happened I saw the high current flash I didn't see it before because I was driving but I just saw it now so I think there's a positive correlation.
>>>
>>> Thank you very much for the insight!
>>>
>>> Keith
>>> AG6AZ
>>>
>>> Sent from my iPhone please excuse typos
>>>
>>> On Sep 21, 2012, at 7:18 AM, "Matt Zilmer" <[hidden email]> wrote:
>>>
>>>> The KX3 probably detected a HI CUR condition. This can happen because
>>>> of high (or low) PS voltage due to automotive electrical fluctuations.
>>>> Sometimes this can happen because of ground current with the antenna
>>>> connected, so check this for a positive correlation.
>>>>
>>>> You should not see HI CUR while on the KX3's internal batteries. This
>>>> proves the automotive supply is caused it.
>>>>
>>>> When the KX3 sees HI CUR (usually something higher than 300 mA on RX),
>>>> it will flash that HI CUR message on VFO A. If the condition
>>>> persists, it will drop the AF gain to some predetermined value. If
>>>> the condition continues beyond that point, the KX3 will shut itself
>>>> off to protect itself. In my own case, both the AF gain and
>>>> self-shutdown events were happening. HI CUR is preventable in a
>>>> mobile setting - see below.
>>>>
>>>> I produced a pretty good document on KX3 mobile ops, which I'm about
>>>> to add to. It's posted on the Elecraft web site at
>>>> http://www.elecraft.com/K2_Manual_Download_Page.htm#kx3_mobile.
>>>>
>>>> Keith, I saw that same type of problem while mobile with KX3 #6 right
>>>> up until I installed a DC-DC converter. See the doc for details of
>>>> all that.
>>>>
>>>> 73,
>>>> matt W6NIA
>>>> KX3 #6, K3 #24, etc.
>>>>
>>>> On Fri, 21 Sep 2012 05:45:18 -0700, you wrote:
>>>>
>>>>> I had this happen to me during mobile operations and not sure why either. Signals dropped right out and then when I turned off the radio for a few minutes and when i turned on the KX3 it went back to where it was prior and remained that way.
>>>>>
>>>>> I will keep an eye on it to see if it happens again.
>>>>>
>>>>> Keith
>>>>> AG6AZ
>>>>>
>>>>> Sent from my iPhone please excuse typos
>>>>>
>>>>> On Sep 20, 2012, at 7:43 PM, "Kevin Luxford" <[hidden email]> wrote:
>>>>>
>>>>>> Hi Guys,
>>>>>> My KX3 has just developed an apparent fault - the audio level changes
>>>>>> abruptly every few seconds from a comfortable listening level to quiet,
>>>>>> but still audible.
>>>>>>
>>>>>> I am using my Proset headphones.
>>>>>>
>>>>>> Any thoughts on where I should start looking? I am nervous about poking
>>>>>> around surface mount circuits!
>>>>>>
>>>>>> vy 73
>>>>>> Kevin
>>>>>> VK3DAP / ZL2DAP
>>>>>> ______________________________________________________________
>>>>>> 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

Matt Zilmer

Re: KX3 Intermittent changes in audio gain

In reply to this post by Keith Heimbold

We're on (anniversary) travel, but found the doc here on the laptop:

In Figure 2, take a close look at the KX3's DC power input. The DC to
DC converter shown eliminates whatever power impurities remain at this
end of the interior DC branch circuit. Being a boost-buck regulator,
the converter can accept a wide range of input voltages and produces a
steady 13.8VDC (adjustable). The converter used in this example
installation is made by QSKJ (model QS-1212CCBA-80W). In addition to
cleaning up the DC, the converter reduces voltage sag from the smaller
gauge interior wiring. In order to prevent the converter from
introducing its own emissions, a Laird LFB174095 ferrite core was used
with 3 turns of the KX3's stock cable. This killed all converter
emissions.

See
http://ca.picclick.com/DC-DC-Converter-QS-1212CCBA-80W-Power-Supply-251036051706.html.

73,
matt

On Fri, 21 Sep 2012 16:24:43 -0700, you wrote: