Here is something the late Stephenson, KD6OZH pointed out:
Keep in mind that's 100 KHz per carrier. So if there was something
OFDM with multiple carriers....
He also pointed out the image transmission thing as another way to
point out how ridiculous the rules are. That was when he was working
on a 70 cm OFDM based Digital Amateur TV thing written in verilog
On Mon, Jun 3, 2019 at 7:49 PM David Ranch <amprgw(a)trinnet.net> wrote:
Hello Guillaume,
Great to hear that you're willing to try narrower bandwidth offerings!
That's a huge help to give this new mode you're working on a try. To
your other point, unfortunately yes, the FCC restrictions here in the US
are antiquated. Until they can be changed (the request is already been
pending for YEARS), we have to live with them. Please not that it's the
*symbol* rate that's limited for say 70cm. I would imagine that 70cm
would be the most popular band to use in the US to experiment compared
to say 33 cm or 23cm.
I had to look up the whole thing again but here is the exact FCC wording:
http://www.arrl.org/part-97-text
*§97.305 Authorized emission types.*
--
UHF:
70 cm
Entire band
MCW, phone, image, RTTY, data, SS, test
(6), (8).
33 cm
Entire band
MCW, phone, image, RTTY, data, SS, test, pulse
(7), (8), and (12).
23 cm
Entire band
MCW, phone, image, RTTY, data, SS, test
(7), (8), and (12).
(f) The following standards and limitations apply to transmissions on
the frequencies specified in §97.305(c) of this part.
(6) A RTTY, data or multiplexed emission using a specified digital
code listed in §97.309(a) of this part may be transmitted. The symbol
rate must not exceed 56 kilobauds. A RTTY, data or multiplexed emission
using an unspecified digital code under the limitations listed in
§97.309(b) of this part also may be transmitted. The authorized
bandwidth is 100 kHz.
(7) A RTTY, data or multiplexed emission using a specified digital code
listed in §97.309(a) of this part or an unspecified digital code under
the limitations listed in §97.309(b) of this part may be transmitted.--
(8) A RTTY or data emission having designators with A, B, C, D, E,
F, G, H, J or R as the first symbol; 1, 2, 7, 9 or X as the second
symbol; and D or W as the third symbol is also authorized.
(12) Emission F8E may be transmitted.
--
--David
KI6ZHD
On 06/03/2019 01:16 PM, f4hdk wrote:
Hello,
Yes, I will try to provide smaller bandwidths in the following months
(or weeks?) for NPR. Probably ~180kHz, which could carry ~90kbps with
2GFSK and ~160kbps with 4GFSK (net datarate).
But I don't think that I will propose modulation parameters which
could match the (very small) FCC restrictions (100kHz and 56kbaud if I
remember well). This rule seems outdated to me... even if it still
applies.
Do not hesitate to take a look regularly at my hackaday web-page in
order to keep informed about "New Packet Radio".
https://hackaday.io/project/164092-npr-new-packet-radio
73,
Guillaume F4HDK
Le 03/06/2019 à 04:00, David Ranch a écrit :
Great to hear and thanks for the update Mark. Has there been any
mention of supporting smaller bandwidths in the future?
--David
KI6ZHD
On 06/02/2019 05:27 PM, Mark Phillips wrote:
Got a pair of these modems working! They are just
running across the
bench
right now. I have an RPi3 and a MMDVM hotspot connected to the
client (via
a switch) with the master connected to a spare port on the back of my
pfSense firewall. I'm using mode "22" which is 270KHz wide for about
220kbps of data bandwidth. This seems more than able to handle the
serving
of a web age and running the MMDVM. I also did a test in 500kbps
mode using
a wifi hotspot attached to the client. I was able to sustain a "wifi
calling" cellphone conversation for over an hour with no issues.
For those not following the project, new firmware was released this
weekend
that allows tuning of the RF from 420-450MHz which is a great
improvement
over the EU only bandplan.
Take a look here
http://g7ltt.dyndns.org:2210
Mark
G7LTT/NI2O
On Tue, Mar 26, 2019 at 4:24 PM Steve L via 44Net
<44net(a)mailman.ampr.org>
wrote:
> In case anyone feels the need:
>
> It's pretty easy to file a petition through the ECFS. When you go to
> the main ECFS page
>
https://www.fcc.gov/ecfs/filings
> in "Type of filing" select "petition for rule making", and fill
out
> the rest of the form and upload your petition.
>
> A couple useful pages from the FCC:
> <
>
https://www.publicknowledge.org/assets/uploads/blog/RP_FCCPetitiontoDeny.pdf
>
> <https://www.fcc.gov/about-fcc/rulemaking-process>
> Here is a quick summary from the last one, three are more details
> on the
> page.
> *Organized comments*.
> *Clear explanation and support for views*.
> *Alternatives. *
> *Examples of concerns.*
> *Statutory limitations.*
>
> It's also helpful to review recent amateur petitions and the FCC
> response. The rejections are a wealth of information on what not to
> do.
> It might be advisable to suggest RM-11392 and DA 08-1092 rejection,
> RM-11699 and DA 13-1918 rejection, as starting points since its
> somewhat related.
>
> Don't use ham jargon, be sure sure to explain acronyms at least once
> in the filing, if repeated makes it easier to follow.
> Don't bash other amateur modes or practices. Don't use technical terms
> unless fully explained so a lawyer can understand, most on the
> Commission are non-tech types.
> Don't ask to ban anything, if you want that done make the case to the
> FCC that whatever it is is poor practice without requesting a
> ban......let them do it.
>
> Do make your petition concise and to the point without a lot of
> rambling and legalese.
> Do provide a reason as to why it's a benefit to the amateur service as
> a whole, also in the public interest if it applies.
> Do have someone, with the background to understand it, proofread and
> comment.
> Do be ready for rebuttal of comments if there are any opposing....wait
> for the "reply to comment" period, this isn't an internet forum
> squabble.
> Keep comments/reply to civil and professional.
>
>
>
> On Sun, Mar 24, 2019 at 3:13 PM Ron Economos via 44Net
> <44net(a)mailman.ampr.org> wrote:
>> This keeps coming up. Has anyone ever submitted a petition for rule
>> making to the FCC? Or are folks afraid that stirring the pot will get
>> DATV banned on 70 cm?
>>
>> Ron W6RZ
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