[RTTY] RM-11708 FAQ posted
k.siwiak at ieee.org
Wed Feb 26 18:33:51 EST 2014
Yes you can, as long as it strobes at a rate ("symbol rate") less than 300 baud,
AND, it can't be just wide band noise. Iit must be a real digital signal. An
OFDM (similar to WiFi) signal that wide would be easy to generate and would be
OK, as long as it adheres to the 300 baud limit. And of course it would not be
a friendly or gentlemanly way to use that spectrum. But, it is NOT prohibited
today, unless RM-11708 takes effect.
The point is you CAN do that today under current rules - one of the ARRL FAQs
points that out, there are no BW limitations today (except for 2-tone RTTY).
By comparison, Canada restricts BW to 6 kHz below 28 MHz (and has no mode sub
bands), except at 60 m where they adopted the USA rules and 30m where the BW is
On 2/26/2014 2:35 PM, Jim W7RY wrote:
> I think you need to double check a few things here... Or can I fire up the old
> wide band generator on 160 meters and cover the entire band at once?
> Jim W7RY
> On 2/26/2014 11:08 AM, Kai wrote:
>> This may help. Here are a couple of FAQ's they did not ask, here they are
>> with my answers.
>> "What is the current limitation on bandwidth of digital emission (except
>> two-tone RTTY) at MF and HF?"
>> The answer is:
>> What is permitted today with no changes in the regs, is digital signals
>> (except two-tone RTTY) with the following bandwidths:
>> 160m - 200 kHz BW
>> 80 m - 100 kHzBW
>> 60m - 2.8 kHzBW [confined to the center of the channels, including two tone
>> 40 m - 125 kHzBW
>> 30 m - 50 kHzBW
>> 20 m - 150 kHzBW
>> 17 m - 42 kHzBW
>> 15 m - 200 kHzBW
>> 12 m - 40 kHzBW
>> 10 m - 300 kHzBW
>> The above are slightly lower for non-Extra class licensees in some bands.
>> "What is the bandwidth limitation on two-tone RTTY today?"
>> All MF and HF bands: 1.5 kHz, except 60 m channels where 2.8 kHz is permitted
>> for all including RTTY.
>> "What is the data bandwidth limitation asked for in RM-11802?"
>> All MF and HF bands, all digital data emissions, including RTTY, limited to
>> 2.8 kHz.
>> In the MF and HF phone bands there are likewise no statutory BW limitations,
>> but the widest that I know off is D-Star digital voice which occupies about 6
>> kHz, and good 'ole AM - also 6 kHz.
>> That's it. That's all there is.
>> Kai, KE4PT
>> On 2/26/2014 12:47 PM, Don AA5AU wrote:
>>> I don't understand this one:
>>> * Shouldn’t 2.8 kilohertz bandwidth data emissions be restricted to the
>>> band segments where phone and image communications are permitted?-
>>> While some commenters have argued for that, it is far beyond the scope of
>>> the ARRL petition. It would require a complete reordering of the regulatory
>>> scheme for the HF bands which would be controversial, to say the least.
>>> I don't understand the part about having to completely reorder the
>>> regulatory scheme. That sounds like a bunch of malarkey.
>>> And are they trying to say the current proposal is not already controversial
>>> Don AA5AU
>>>> From: Ron Kolarik<rkolarik at neb.rr.com>
>>>> To: RTTY<rtty at contesting.com>
>>>> Sent: Wednesday, February 26, 2014 1:02 AM
>>>> Subject: [RTTY] RM-11708 FAQ posted
>>>> The ARRL FAQ is up
>>>> I haven't had time to go through it yet.
>>>> RTTY mailing list
>>>> RTTY at contesting.com
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>>> RTTY at contesting.com
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