Free DV (digital voice as reported in QST-April issue)

[ab2tc]

Hi again,

This slightly OT thread is becoming rather long but I'll risk another entry. Nobody has addressed the issue about whether these types of signals are actually permitted in our phone bands. I have never seen a precise definition of what the FCC means with the terms "phone", "digital" or "image". If digital voice meats the criteria for "digital", according to FCC they should go in the CW portion of the bands! I can't imagine that would be popular with the CW folks.

AB2TC - Knut

Bill Frantz wrote

On 4/3/13 at 3:47 PM, [hidden email] (Lynn W. Taylor, WB6UUT) wrote:

> Lyle answered me offlist and told me to RTFM, page 18.

And thank you Lyle for "The Fine Manual".

Bill, AE6JV
<snip>

[ab2tc]

Correction,

Replace term "digital" below with "data".

Knut - AB2TC

ab2tc wrote

Hi again,

This slightly OT thread is becoming rather long but I'll risk another entry. Nobody has addressed the issue about whether these types of signals are actually permitted in our phone bands. I have never seen a precise definition of what the FCC means with the terms "phone", "digital" or "image". If digital voice meats the criteria for "digital", according to FCC they should go in the CW portion of the bands! I can't imagine that would be popular with the CW folks.

AB2TC - Knut

<snip>

[Julian, G4ILO]

I have set it up that way, Don, and it works fine. I was in QSO with someone who had a Flex and I was running 25W and I increased the power to 40W and he told me that he was still getting perfect copy and could detect no increase in bandwidth. You really have to try hard to make a K3 splatter.

Julian, G4ILO

Don Wilhelm-4 wrote

Since this is just another digital mode, why would you not set the K3
ALC indication as specified for other digital modes.  4 bars on the ALC
meter with the 5th bar flickering.

If you do not do it that way, the K3 will "power hunt" and you will not
have consistent power output.
Bring the audio up as indicated in the digital operation section of the
K3 manual and set the power knob for the desired power output.

73,
Don W3FPR

[Richard Fjeld]

I have thought about this also.  

Some data modes use carrier, others are audio.  Some data modes in the phone portion will conserve bandwidth, but will consume bandwidth in the CW portion.

It will be interesting to see how it sorts out.

Rich, n0ce

  ----- Original Message -----
  From: ab2tc
  To: [hidden email]
  Sent: Friday, April 05, 2013 9:18 AM
  Subject: Re: [Elecraft] Free DV (digital voice as reported in QST-Aprilissue)


  Correction,

  Replace term "digital" below with "data".

  Knut - AB2TC


  ab2tc wrote
  > Hi again,
  >
  > This slightly OT thread is becoming rather long but I'll risk another
  > entry. Nobody has addressed the issue about whether these types of signals
  > are actually permitted in our phone bands. I have never seen a precise
  > definition of what the FCC means with the terms "phone", "digital" or
  > "image". If digital voice meats the criteria for "digital", according to
  > FCC they should go in the CW portion of the bands! I can't imagine that
  > would be popular with the CW folks.
  >
  > AB2TC - Knut
  > <snip>





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[Richard Fjeld]

It was me that was under question by Don.  I am glad to learn of the correct way, but I must say that I received very good reports the way I was running it.  However, I like the way the ALC looks using Don's recommendation.

As a comment, many of the people I have heard running freeDV are using Flex radios, yet a K3 is so simple to use and so few.  Go figure.

Rich, n0ce


  ----- Original Message -----
  From: Julian, G4ILO
  To: [hidden email]
  Sent: Friday, April 05, 2013 12:10 PM
  Subject: Re: [Elecraft] Free DV (digital voice as reported in QST-Aprilissue)


  I have set it up that way, Don, and it works fine. I was in QSO with someone
  who had a Flex and I was running 25W and I increased the power to 40W and he
  told me that he was still getting perfect copy and could detect no increase
  in bandwidth. You really have to try hard to make a K3 splatter.

  Julian, G4ILO


  Don Wilhelm-4 wrote
  > Since this is just another digital mode, why would you not set the K3
  > ALC indication as specified for other digital modes.  4 bars on the ALC
  > meter with the 5th bar flickering.
  >
  > If you do not do it that way, the K3 will "power hunt" and you will not
  > have consistent power output.
  > Bring the audio up as indicated in the digital operation section of the
  > K3 manual and set the power knob for the desired power output.
  >
  > 73,
  > Don W3FPR





  -----
  Julian, G4ILO. K2 #392  K3 #222 KX3 #110
  * G4ILO's Shack - http://www.g4ilo.com
  * KComm - http://www.g4ilo.com/kcomm.html
  * KTune - http://www.g4ilo.com/ktune.html

  --
  View this message in context: http://elecraft.365791.n2.nabble.com/Free-DV-digital-voice-as-reported-in-QST-April-issue-tp7572113p7572249.html
  Sent from the Elecraft mailing list archive at Nabble.com.
  ______________________________________________________________
  Elecraft mailing list
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[Eduardo González]

Digital modes as DV use a confined portion of BW, less than BW required by
SSB audio signal of relative high quality. Certainly is impossible the
coexistence of DV signal with audio signal at same channel, including
another DV signal, however several DV signals located one next to the other
are perfectly decoded (into normal audio BW of 3.3 Khz can be three DV
channels) but three audio signals located same manner become to non
discernible signals.

Edu YY4GMJ


On Fri, Apr 5, 2013 at 1:08 PM, Richard Fjeld <[hidden email]>wrote:

> It was me that was under question by Don.  I am glad to learn of the
> correct way, but I must say that I received very good reports the way I was
> running it.  However, I like the way the ALC looks using Don's
> recommendation.
>
> As a comment, many of the people I have heard running freeDV are using
> Flex radios, yet a K3 is so simple to use and so few.  Go figure.
>
> Rich, n0ce
>
>
>   ----- Original Message -----
>   From: Julian, G4ILO
>   To: [hidden email]
>   Sent: Friday, April 05, 2013 12:10 PM
>   Subject: Re: [Elecraft] Free DV (digital voice as reported in
> QST-Aprilissue)
>
>
>   I have set it up that way, Don, and it works fine. I was in QSO with
> someone
>   who had a Flex and I was running 25W and I increased the power to 40W
> and he
>   told me that he was still getting perfect copy and could detect no
> increase
>   in bandwidth. You really have to try hard to make a K3 splatter.
>
>   Julian, G4ILO
>
>
>   Don Wilhelm-4 wrote
>   > Since this is just another digital mode, why would you not set the K3
>   > ALC indication as specified for other digital modes.  4 bars on the ALC
>   > meter with the 5th bar flickering.
>   >
>   > If you do not do it that way, the K3 will "power hunt" and you will not
>   > have consistent power output.
>   > Bring the audio up as indicated in the digital operation section of the
>   > K3 manual and set the power knob for the desired power output.
>   >
>   > 73,
>   > Don W3FPR
>
>
>
>
>
>   -----
>   Julian, G4ILO. K2 #392  K3 #222 KX3 #110
>   * G4ILO's Shack - http://www.g4ilo.com
>   * KComm - http://www.g4ilo.com/kcomm.html
>   * KTune - http://www.g4ilo.com/ktune.html
>
>   --
>   View this message in context:
> http://elecraft.365791.n2.nabble.com/Free-DV-digital-voice-as-reported-in-QST-April-issue-tp7572113p7572249.html
>   Sent from the Elecraft mailing list archive at Nabble.com.
>   ______________________________________________________________
>   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
>

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[W6ODJ]

Hi Eduardo,

I think you've hit the problem.  A DV signal takes up, say, 2 kHz but it really takes it up.  Even when the speaker is pausing, there is still a signal sort of like a RTTY diddle filling the bandwidth.  This may give the subjective impression that a DV signal is more intrusive than an analog SSB one.  Also in a three-way SSB QSO two people can try to talk at the same time and both will at least be heard.  It is a bit like conversing at a party trying to focus on the speaker you want to hear.  But they don't completely cut each other off with SSB.  Maybe DV can have aggressive VOX so that it turns off when there are pauses?  Sort of digital break in keying?

73,

Oliver
W6ODJ


On 5 Jan. 2013, at 11:23 AM, Eduardo González <[hidden email]> wrote:

> Certainly is impossible the
> coexistence of DV signal with audio signal at same channel, including
> another DV signal

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[ve3dvy]

I did a little research on FCC Regs and found this according to a sub
article in QEX May/June 2000



"The transmission of telephony in digital format
(emission designator J1E or J2E) is
perfectly legal in the phone bands. The
restriction placed on transmitted baud
rate by §97.307(f)(3) of the FCC rules does
not apply. In fact, there is no upper limit
on the bit rate for this mode."


and later in a box on the second page it starts

Is Digital Voice Permissible under Part 97?
There has been some discussion about
Part 97 of the FCC Rules and whether
digital voice is “legal.” A careful
reading of the Rules will show that
digital voice is indeed provided for

The whole article can be read here

http://www.arrl.org/files/file/Technology/tis/info/pdf/0056x003.pdf

see the box on the second page which explains it in detail.
Unfortunately the main article is somewhat over my head much like most
stuff in QEX but I keep reading anyway.

In Canada we have less restrictions regarding the band plans and Digital
Voice is allowed here as well.

David Moes

[hidden email]
VE3DVY

On 4/5/2013 1:17 PM, Richard Fjeld wrote:

> I have thought about this also.
>
> Some data modes use carrier, others are audio.  Some data modes in the phone portion will conserve bandwidth, but will consume bandwidth in the CW portion.
>
> It will be interesting to see how it sorts out.
>
> Rich, n0ce
>
>    ----- Original Message -----
>    From: ab2tc
>    To: [hidden email]
>    Sent: Friday, April 05, 2013 9:18 AM
>    Subject: Re: [Elecraft] Free DV (digital voice as reported in QST-Aprilissue)
>
>
>    Correction,
>
>    Replace term "digital" below with "data".
>
>    Knut - AB2TC
>
>
>    ab2tc wrote
>    > Hi again,
>    >
>    > This slightly OT thread is becoming rather long but I'll risk another
>    > entry. Nobody has addressed the issue about whether these types of signals
>    > are actually permitted in our phone bands. I have never seen a precise
>    > definition of what the FCC means with the terms "phone", "digital" or
>    > "image". If digital voice meats the criteria for "digital", according to
>    > FCC they should go in the CW portion of the bands! I can't imagine that
>    > would be popular with the CW folks.
>    >
>    > AB2TC - Knut
>    > <snip>
>
>
>
>
>
> ______________________________________________________________
> 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
>

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