K3S drops 10db with Digital Modes

[Karel Cornelis]

Hi,


Somebody mentioned me that my signals goes up and down about 10db when I send out digital mode via pc. (psk, simpsk). ( checked it myself via  a websdr station close to my QTH, so no propagation )

I already switched off TX ALC but there is no difference. Compressor is off, tried low and high power, low and high output of pc sound does not change a thing, TX EQ is not used, ...

When I do the same with my Flex, with the same pc and the same programs I don't have this up and down issue.

I checked the USB Audio Codec sound card settings, but I don't see any settings in there that could cause this issue.

Has anybody got an idea about this? It's not a real issue to work digital modes, but I'm curious to know of what is causing this.


Tnx 73 Karel

ON7TA

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[Richard Ferch-2]

Karel,

What is the reading on the K3S's ALC meter? In order to achieve correct
power control in audio data modes, you must set the audio input level so
that the meter reads 4-5 bars - not zero as with most other transceivers.
If the audio input is at zero bars, the K3S's microprocessor will not be
able to control the transmitter output power correctly.

Set the audio level to give you 4-5 bars on the ALC meter,and use the PWR
control to select the desired output power. Do not leave the PWR control at
full power and use the audio drive level to control output power, as is
sometimes recommended for other transceivers - that will not work with the
K3 and K3S.

73,
Rich VE3KI



ON7TA wrote:

Somebody mentioned me that my signals goes up and down about 10db when I
send out \
digital mode via pc. (psk, simpsk). ( checked it myself via  a websdr
station close \
to my QTH, so no propagation )

I already switched off TX ALC but there is no difference. Compressor is
off, tried \
low and high power, low and high output of pc sound does not change a
thing, TX EQ is \
not used, ...

When I do the same with my Flex, with the same pc and the same programs I
don't have \
this up and down issue.

I checked the USB Audio Codec sound card settings, but I don't see any
settings in \
there that could cause this issue.

Has anybody got an idea about this? It's not a real issue to work digital
modes, but \
I'm curious to know of what is causing this.
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Help: http://mailman.qth.net/mmfaq.htm
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[Karel Cornelis]

Hi Rich,


Thanks for your response.

The way you describe it is exact the same way I do it.

I do not use the Audio drive level to control the output power and ALC is around 4 to 5 bars. (it was for testing purposes to see if it did change something to the up-down phenomena)

I going to swap the Power Supply this evening, maybe that is the issue.


thanks


73's Karel

ON7TA


________________________________
From: Richard Ferch <[hidden email]>
Sent: 29 April 2016 12:49
To: [hidden email]
Cc: Karel Cornelis
Subject: Re: [Elecraft] K3S drops 10db with Digital Modes

Karel,

What is the reading on the K3S's ALC meter? In order to achieve correct power control in audio data modes, you must set the audio input level so that the meter reads 4-5 bars - not zero as with most other transceivers. If the audio input is at zero bars, the K3S's microprocessor will not be able to control the transmitter output power correctly.

Set the audio level to give you 4-5 bars on the ALC meter,and use the PWR control to select the desired output power. Do not leave the PWR control at full power and use the audio drive level to control output power, as is sometimes recommended for other transceivers - that will not work with the K3 and K3S.

73,
Rich VE3KI



ON7TA wrote:

Somebody mentioned me that my signals goes up and down about 10db when I send out \
digital mode via pc. (psk, simpsk). ( checked it myself via  a websdr station close \
to my QTH, so no propagation )

I already switched off TX ALC but there is no difference. Compressor is off, tried \
low and high power, low and high output of pc sound does not change a thing, TX EQ is \
not used, ...

When I do the same with my Flex, with the same pc and the same programs I don't have \
this up and down issue.

I checked the USB Audio Codec sound card settings, but I don't see any settings in \
there that could cause this issue.

Has anybody got an idea about this? It's not a real issue to work digital modes, but \
I'm curious to know of what is causing this.

______________________________________________________________
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]