Yeah, and there is a reason for that.

  I purchased a digital voice Modem sold commercially by Alinco for a few hundred bucks (on sale) and deployed it on 40 meters for a Sunday morning net we held back some 15  years ago or so among my Dayton hamfest buddies.  It is difficult on HF to run unless conditions are perfect and there is little or no interference or fading.  We ended up reverting to analog SSB after trying it for a while-I can now say been there-done that.   I still have the modem in new condition but have not fired it up in ages.  Plugs into the analog audio input of any SSB rig.   They work OK.  It is 100% duty cycle of course and is just not preferred to decent quality SSB under clear or difficult conditions. You would not really be impressed.  It was worth trying but as you know, no one is running out to get digital voice on HF even though it can be made widely available for little money these days.

Maybe someday, but why?  In 25 years there may be new and unheard-of methods which are narrow band and immune to noise, interference and harsh conditions.  Hams will be the first to deploy them again, but not for awhile.

Bob Famiglio, K3RF

Vice Director - ARRL Atlantic Division

610-359-7300

www.QRZ.com/db/K3RF

From: arrl-odv On Behalf Of Michael Ritz
Sent: Tuesday, July 30, 2019 2:19 PM
To: arrl-odv@reflector.arrl.org
Subject: [arrl-odv:28467] Re: HF Digital Voice Effectively Stopped?

Interesting article, Mark. Thanks for sharing it!  Looks like the technology's been around for a while, but has never really caught on.

73;

Mike

W7VO

On July 30, 2019 at 11:04 AM Mark J Tharp <kb7hdx@gmail.com> wrote:

This from May/June QEX back in 2000 FYI

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

Mark, HDX

On Tue, Jul 30, 2019 at 10:50 AM Michael Ritz < w7vo@comcast.net> wrote:

Dick;

In my view, the real question is: What's the difference between digital voice and any other digital signal? In the end, they're all something converted into ones and zeros, stuffed into packets, transmitted over the air, and packets reassembled and decoded at the other end.  If you are going to allow digital voice in the SSB portions of the bands, you might as well allow all digital signals across the bands too, and I think that is what we were trying to address. 

I don't see this as stifling technology.  The bandplans can be changed as technology evolves. Right now we are protecting SSB, which is not proprietary, and easily tuned in by a new ham using a cheap radio. If a new technology emerges we can deal with that when the time comes. I'd like to see temporary experimental licenses issued on a case-by-case basis for new disruptive digital phone technologies first, before we open the phone bands to them.  

I've been asked by a ham just last Thursday to see if we can open up more ACDS channels for increasing Winlink traffic going forward. That's another issue entirely...

It'll be interesting to see what other comments weigh in on this. 

73;

Mike

W7VO

On July 30, 2019 at 10:24 AM "Richard J. Norton" < richardjnorton@gmail.com> wrote:

Digital voice has never been big on HF to the best of my knowledge, but is increasingly being deployed on VHF and also being deployed by commercial interests on frequencies outside the ham bands.

It looks like the motion passed at the last Board meeting on Interference and Enforcement, wll outlaw use of digital voice on frequencies below 28 MHz, except inside the tiny ACDS bands.

(2) All digital mode stations that operate with a bandwidth greater than 500 Hz also must operate within the ACDS bands designated in the FCC's Rules, whether or not automatically controlled.

I'm uncertain how this comports with parts of the basis and purpose of Amateur Radio, such as:

Continuation and extension of the amateur's proven ability to contribute to the advancement of the radio art [97.1(b)]

Encouragement and improvement of the amateur service through rules which provide for advancing skills in both the communication ans technical phases of the art [97.1(c)]

How should the League respond to possible inquiries or complaints about stifling technical advancement?

73,

Dick Norton, N6AA 

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