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Re: bad audio at K4XU

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Dick Frey

Re: bad audio at K4XU

Okay, I need to be more specific about my "bad audio".. The audio is raspy,
like it has rf in it. It is independent of frequency, power, mic type,
recorded or not, Hi or Lo mic gain setting, and mic drive level.

The only other issue I have is that the low power carrier is 5W when the
PWR is set at 12W and jumps to 15W when PWR is set to 13W. It is 100W at
the 100W setting.

Perhaps the two issues are related. CW operation is unaffected.
--
Dick - K4XU
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donovanf

Re: bad audio at K4XU

Hi Dick,

I had the same problem when my power supply voltage was too low
(12 volts with no load).

73
Frank
W3LPL

----- Original Message -----

From: "Dick Frey" <[hidden email]>
To: "Elecraft list" <[hidden email]>
Sent: Friday, December 7, 2018 7:02:54 PM
Subject: Re: [Elecraft] bad audio at K4XU

Okay, I need to be more specific about my "bad audio".. The audio is raspy,
like it has rf in it. It is independent of frequency, power, mic type,
recorded or not, Hi or Lo mic gain setting, and mic drive level.

The only other issue I have is that the low power carrier is 5W when the
PWR is set at 12W and jumps to 15W when PWR is set to 13W. It is 100W at
the 100W setting.

Perhaps the two issues are related. CW operation is unaffected.
--
Dick - K4XU
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k6dgw

Re: bad audio at K4XU

In reply to this post by Dick Frey

Is your power supply stable and at 14V? I had an Astron lose its
regulation becoming "wobbly" and down to about 11.5 V and the K3 audio
sounded like it had RF feedback.

73,
Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

On 12/7/2018 11:02 AM, Dick Frey wrote:
> Okay, I need to be more specific about my "bad audio".. The audio is raspy,
> like it has rf in it. It is independent of frequency, power, mic type,
> recorded or not, Hi or Lo mic gain setting, and mic drive level.
>
> The only other issue I have is that the low power carrier is 5W when the
> PWR is set at 12W and jumps to 15W when PWR is set to 13W. It is 100W at
> the 100W setting.
>
> Perhaps the two issues are related. CW operation is unaffected.

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Bob McGraw - K4TAX

Re: bad audio at K4XU

In reply to this post by Dick Frey

I suggest you use the K3 utility and run a full power calibration. This does require a known good 50 ohm dummy load. If the problem persists, then I suspect failure of the LPA and/or the KPA3 stages. Contact Elecraft support.

Bob, K4TAX

Sent from my iPhone

> On Dec 7, 2018, at 1:02 PM, Dick Frey <[hidden email]> wrote:
>
> Okay, I need to be more specific about my "bad audio".. The audio is raspy,
> like it has rf in it. It is independent of frequency, power, mic type,
> recorded or not, Hi or Lo mic gain setting, and mic drive level.
>
> The only other issue I have is that the low power carrier is 5W when the
> PWR is set at 12W and jumps to 15W when PWR is set to 13W. It is 100W at
> the 100W setting.
>
> Perhaps the two issues are related. CW operation is unaffected.
> --
> Dick - K4XU
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>
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> Please help support this email list: http://www.qsl.net/donate.html
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>

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Bob McGraw - K4TAX

Re: bad audio at K4XU

In reply to this post by k6dgw

Good point Fred. Yes the voltage at the radio should be 13 to 14 volts under all conditions. Check power cables and connectors, visually, physically, and electrically.

Bob, K4TAX

Sent from my iPhone

> On Dec 7, 2018, at 1:19 PM, Fred Jensen <[hidden email]> wrote:
>
> Is your power supply stable and at 14V? I had an Astron lose its regulation becoming "wobbly" and down to about 11.5 V and the K3 audio sounded like it had RF feedback.
>
> 73,
> Fred ["Skip"] K6DGW
> Sparks NV DM09dn
> Washoe County
>
>> On 12/7/2018 11:02 AM, Dick Frey wrote:
>> Okay, I need to be more specific about my "bad audio".. The audio is raspy,
>> like it has rf in it. It is independent of frequency, power, mic type,
>> recorded or not, Hi or Lo mic gain setting, and mic drive level.
>>
>> The only other issue I have is that the low power carrier is 5W when the
>> PWR is set at 12W and jumps to 15W when PWR is set to 13W. It is 100W at
>> the 100W setting.
>>
>> Perhaps the two issues are related. CW operation is unaffected.
>
> ______________________________________________________________
> 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]

Joe Subich, W4TV-4

Re: bad audio at K4XU

>>> On 12/7/2018 11:02 AM, Dick Frey wrote:
>>> The only other issue I have is that the low power carrier is 5W
>>> when the PWR is set at 12W and jumps to 15W when PWR is set to
>>> 13W. It is 100W at the 100W setting.
This "smells" like an LPA failure to me. Low power should increase
smoothly from 0 to 12 W. The HPA should kick in above 12 W and the
power should increase smoothly again. The behavior is very much like
severe compression above 5W in the LPA.

I would first perform both the LP and HP power calibration. If that
does not resolve the issue I would contact Elecraft Support.

73,

... Joe, W4TV

>>> On 12/7/2018 11:02 AM, Dick Frey wrote:
>>> Okay, I need to be more specific about my "bad audio".. The audio is raspy,
>>> like it has rf in it. It is independent of frequency, power, mic type,
>>> recorded or not, Hi or Lo mic gain setting, and mic drive level.
>>>
>>> The only other issue I have is that the low power carrier is 5W when the
>>> PWR is set at 12W and jumps to 15W when PWR is set to 13W. It is 100W at
>>> the 100W setting.
>>>
>>> Perhaps the two issues are related. CW operation is unaffected.
>>