[HCARC] Fw: FW: SYSTEM FUSION NET

Thu Nov 27 21:45:32 EST 2014

OK guys and gals, your killing the idea with speculation.
Me, it's HARD DATA that counts.

If your unsure, follow the San Antonio Fusion project, wait 6 months and see
what the problems are, THEN make a decision.

Don't kill the idea on "I think" it's this way or "This will happen".
Keep an open mind.

--eddie AF5SA

On Thu, Nov 27, 2014 at 8:27 PM, Kerry Sandstrom <kerryk5ks at hughes.net>
wrote:

> That's exactly right, Gary.
>
> Let me take you all back about 35 years.  Has anyone ever heard of Narrow
> Band Voice Modulation (NVBM)?  Let me quote from "It Seems to US..." in the
> Sept 1978 QST.  This is an editorial by Dick Baldwin, W1RU, General Manager
> of the ARRL .  In those days the General manager was the same as today's
> Executive Vice President or Chief Executive Officer or whatever K1ZZ's
> latest title is.  The editorial is titled "Dawn of an Era"  It starts with
> "Last December we were privileged to share with League members the first
> published information on a technological breakthrough which promises to
> revolutionize voice communications: narrow band  voice modulation (nbvm).
> Nvbm is a technique for compressing speech frequencies so that only about
> half the normal bandwidth is used."  It says later in the editorial, "Nbvm
> has important applications to other services as well.  An FCC study group
> has conducted tests of the system for Land Mobile applications and has
> tentatively concluded that a considerable saving of spectrum could be
> accomplished by replacing the present fm mobile equipment with
> single-sideband gear using nbvm."   The editorial concludes with "We're
> proud that through QST, League members will be able to be at the forefront
> of this important development."
>
> Not only didn't it become a popular amateur mode, it hasn't even been
> utilized by the LMR community.  I don't believe there were very many if any
> NBVM radios manufactured by anyone for any use.  It just wasn't worth the
> trouble and just didn't work that well.  I believe the commercial versions
> of digital radio such as P25, TETRA and perhaps DMR will be used in the LMR
> bands.  One of the drivers in the Public Safety bands is the need for
> secure (encrypted) voice. This pretty much requires digital techniques.
> But encryption is not legal in the amateur bands so this isn't a player for
> us.  I don't know how useful or practical digital voice will be for hams
> and I sure would take a wait and see attitude until it proves itself to be
> practical, inexpensive and popular.
>
> My last e-mail, I talked about the need for linear amplifiers.  The
> digital modulation schemes do use multiple carriers.  System Fusion claims
> to use C4FM which has 4 carriers.  Typically to linearize an FM amplifier,
> you have to reduce the gain by 6 - 10 dB.  Now your 10 W FM transmitter is
> a 1 - 2.5 W transmitter for C4FM.  That is quite a hit.
>
> Kerry
>
>
>
> On 11/26/2014 11:27 PM, Gary J - N5BAA wrote:
>
>>
>>
>> -----Original Message----- From: Gary J - N5BAA
>> Sent: Wednesday, November 26, 2014 11:26 PM
>> To: Kerry Sandstrom
>> Subject: Re: [HCARC] FW: SYSTEM FUSION NET
>>
>> Do you mean Kerry that "IF THEY BUILD IT - THEY (WE) DON'T HAVE TO COME"??
>> Heck, Bill Tynan recently put up a 900 mhz repeater at his cost and I'd
>> bet
>> there are very few that have started using that one.  I might, but every
>> Alinco 900 mhz handheld I find costs me well over $200 (closer to 300)
>> dollars.  I then can make a choice to spend the $$$ on coax or antennas
>> for
>> HF and sorry Bill - 900 mhz loses out.  I have asked on here if there is a
>> less cost 900 mhz radio out there, but to date haven't heard one
>> suggestion.
>> The last thing I need to do would be buy a Fusion radio to have it sit
>> idle
>> too.
>>
>> BTW, for the new guys - VERTEX Standard makes Yaesu.
>>
>> Gary J
>> N5BAA
>>
>> -----Original Message----- From: Kerry Sandstrom
>> Sent: Wednesday, November 26, 2014 9:11 PM
>> To: Gary J - N5BAA
>> Subject: Re: [HCARC] FW: SYSTEM FUSION NET
>>
>> Gary et al,
>>
>> I think Gary has made a good comparison.  This is kind of like the Beta
>> vs. VHS VCR battles.  Many would suggest that that battle was one not by
>> the best technical system but the one that was least expensive. There
>> are still people who are trying to keep Beta alive.  Unfortunately both
>> seem to have lost out to DVD and then Blu-ray.  There are some
>> differences however.  We don't have 2 competing systems - we have at
>> least 5.  The three additional ones are TETRA, the European LMR digital
>> system, P25 the US LMR digital system and DMR, another European LMR
>> system.  Because of FCC rules on bandwidth in the LMR bands, I expect
>> every public safety 2-way radio in North America will be a P25 digital
>> radio.  Same thing is happening in Europe except it will be TETRA.  Why
>> do hams want to create a different incompatible system.
>>
>> All the systems claim compatibility with analog FM but none claim any
>> compatibility with other digital systems.  As a minimum, we need to wait
>> to see which system is the winner.  Cost will eventually be determined
>> by economy of scale.  Companies selling P25 radios include Motorola,
>> Codan, Harris, Midland and the commercial parts of ICOM, Kenwood and
>> Vertex Standard.
>>
>> I don't have any idea of how the FCC will eventually react to these
>> systems in the ham bands.  Already, I believe the 2 meter band can't be
>> used for remote control.  I'm not sure what the restrictions are or may
>> be applied to 9600 baud data.
>>
>> Some of the digital systems require linear amplifiers.  I don't know if
>> all do.  TETRA is one that I believe does require linear amps. Yes,
>> digital signals do and will cause interference.  Turning the squelch up
>> merely ensures that you won't hear weak FM analog signals that are
>> receiving digital interference.  That means some of the weaker analog FM
>> signals will not be workable.  Typical narrowband digital signals
>> require a higher S/N than analog FM, that's why the coverage of the
>> digital signals is not as good as the analog signals.  Error correction,
>> FEC, and coding help with pulse type interference but do little for
>> continuous interference. Unfortunately the response of most digital
>> systems to interference is to retransmit the messages that can't be
>> decoded probably.  This doesn't exactly help the interference situation.
>>
>> I'm not sure what compatibility really means in the case of repeaters.
>> What I think it means is that a digital signal will be repeated as a
>> digital signal and an analog signal will be repeated as an analog
>> signal.  I don't think a digital user will be able to talk to an analog
>> user.  I may be wrong, but that is how I interpreted compatibility.
>>
>> So where does that leave us?  Digital and analog on the same repeater
>> simultaneously is not realistic.  When both are present at the same
>> level, I think digital will suffer more than analog. Digital coverage at
>> the same power levels will be less than analog. I would wait until there
>> is a real standard with real support. Right now, I don't think either
>> Dstar or Fusion will be that standard.  Finally, yes there are a lot of
>> fun things you can do with data, but I don't know how many of them are
>> legal, especially in the 2 meter band.
>>
>> No, I'm not a fan of digital systems on the ham bands.
>>
>> Kerry
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
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