New DigiMode — ROS. 1st QSO this evening.

ROS

I have a copy of it posted on my ham radio file server. I find it to be usefull to keep a copies of programs I might need stored there in case I need it at another location.

I have it set up for access by anonymous users. You should be able to click on the link below and have access to the files. Look for a folder called ROS. Double click it and you will see the file to download.

It may also be downloaded from my web page [use this link direct to the page].

 

ROS seems very nice. I've been experimenting with Olivia and others a while back.
The only downside is that there is yet another mode to choose from. When scanning the spectrum, it doesn't get any simpler trying to decode the signals.

Another example of the fact that Norton is not up to the quality standard is was once. I've read more Norton reviews about these sort of problems.

 

I am not Lord Haw-Haw

Yup, It's real Dodgy looking Programme .. Check out the ROS 'About' dialogue.

"Don't let's be Beastly to the Germans".
— Sir Noël Coward, 1943.

I'll never let them be able to accuse me of gullibly being misled into shamelessy promoting the enemy's message.
I am not Lord Haw-Haw

 

I am not Lord Haw-Haw

Yup, It's real Dodgy looking Programme .. Check out the ROS 'About' dialogue.

That's a German U-Boat for those without their Glasses.

I'll never let them be able to accuse me of gullibly being misled into shamelessy promoting the enemy's message.
I am not Lord Haw-Haw

"Don't let's be Beastly to the Germans".
— Sir Noël Coward, 1943.

 

Just what we need yet another data mode and one that at 2.2kHz is almost as wide as voice. Divide and conquer.

 

Actually it's 2.2kHz, but I still agree with you Steve, in fact that was exactly what I was going to say only you got there first.

Up on the wide open spaces of VHF it may not be a problem but there just isn't enough space for digimodes that wide on HF. Fine when it's just a couple of experimenters using it, but the more who use it where are they all going to go?

 

Typo Julian I missed the .

 

That's true if, and only if, the baud (a.k.a. signaling) rate equals the bit rate. According to Shannon-Hartley, the maximum error-free bit rate that can be sent on a noisy channel with a bandwidth of 2.2K Hz and a signal-to-noise ratio of -35dB is 1 bps.

Shannon-Hartley formula




S/N = 10^(dB/10)

S/N = 10^(-35/10) ~= 0.000316

C = 2200 * (log(1 + 0.000316) / log(2)) ~= 1 bps

 

Hi, i think you are not doing the numbers correctly.

In this case you cannot write B=2250 Hz, because we are talking about a FHSS modulation.

 

FCC: There Is No HF Digital Data/Text Bandwidth Limit In USA

Given the fact that ROS Modem has been advertised as FHSS Spread Spectrum, it may be quite difficult for USA amateur radio operators to obtain a positive interpretation of rules by FCC to allow use of ROS on HF without some type of experimental license or waiver.

If ROS Modem had simply provided the technical specifications of the emission, and not called it Spread Spectrum, there would have been a chance for it to be easily adopted by Ham Radio operators in USA. But, the ROS modem designer is rightfully proud of the design, and he lives in a country that is not bound by FCC rules, and probably had little or no knowledge of how his advertising might prevent thousands of hams from using it in USA. But, as they say, "you cannot un-ring a bell, once it has been rung ".

ROS signal can be viewed as a type of FSK, similar to various other types of n-ary-FSK presently in widespread use by USA hams. The specific algorithms for signal process and format could simply have been documented without calling it Frequency Hopping Spread Spectrum (FHSS). Since it is a narrowband signal (using the ITU definition of narrowband at less than 3kHz) within the width of an SSB passband, it does not fit the traditional conventional FHSS description. It probably would not have been viewed as FHSS under the spirit and intention of the FCC rules. It doesn't hop the VFO frequency. It simply FSKs according to a programmable algorithm, and it meets the infamous 1kHz shift 300 baud rule.

This is a typical example of how outdated the present FCC rules are, keeping USA hams in Technology Jail while the rest of the world's hams move forward with digital technology. It should come as no surprise that most of the new ham radio digital modes are not being developed in USA!

But, for a moment, let's put aside the issue of current FCC prohibition against Spread Spectrum and/or Frequency Hopping Spread Spectrum, and how it relates to ROS mode. Let's look at bandwidth.

There is the other issue of "bandwidth" that some misguided USA hams have brought up here and in other forums. Some superstitious hams seem to erroneously think that there is an over-reaching "bandwidth limit" in the FCC rules for data/text modes on HF.

There is currently no finite bandwidth limit on HF data/text emission in USA ham bands, except for the sub-band and band edges.

FCC data/text HF rules are still mainly based on content of the emission, not bandwidth.

FCC rules allow hams to transmit a 149kHz bandwidth data/text signal on the 20 meter band. It may not be popular to do so, but it is legal

USA is not alone, amateur radio regulations of many other countries of the world do not have bandwidth limits on signals, but most do not have content-based sub-bands. Bandwidth regulation has been recently adopted by some countries, and bandwidth segmentation is part of the recommended IARU Bandplans for all regions now.

New SDR radios have the potential to transmit and receive wider bandwidths than the traditional 3kHz SSB passband. We will see a lot more development in this area of technology in the future, and a lot more gray areas of the FCC rules that inhibit innovation.

There are other HF services using 6kHz, 12kHz, 24kHz, 24kHz and 48kHz bandwidth fast data modems. Some of these modems are capable of sending a page of text in the time it would take you to call CQ on one of the slow digital modes.

Perhaps there are good potential applications for 48kHz modems in HF ham radio. For example, large portions of the 24MHz, 21MHz, and 28MHz ham bands are almost completely empty of amateur radio signals for years. It would be easy to fit a 24kHz or 48kHz bandwidth signal in these bands without harmful interference.

§97.305(c) Reference Chart:
FCC. Rules. §97.305 Authorized emission types.

§97.305(c) is a chart of amateur radio bands and sub-bands. Each sub-band has a "note", and the notes are listed in part §97.307

The Note # (2) only applies a soft bandwidth
limit to non-phone emissions within the "Phone,image" sub-bands.

Note # (2) does not apply to the CW/data/RTTY sub-bands.

Only Note # (1) applies to the CW/data/RTTY sub-bands.

Several years ago, there was a proposal to FCC to provide regulation by bandwidth rather than content. However, it failed to be adopted, and ARRL's petition to limit bandwidth was withdrawn.

Thus, USA hams still don't have a bandwidth limit for HF data/text.

Best Wishes,

 

Do you even know why those bands are not used much right now? I can't believe you could be that dumb. The solar cycle is still at a minimum and those particular bands are dead because they are not the greatest for long haul comms right now. Back in 2000 when 10m was open I used it all the time to have QSO's from Georgia to Germany with only 25 watts. Just because they seem quite to you does not mean they will be in a few years. Just another pathetic attempt by you to grab more bandwidth instead of really innovating and trying to squeeze more speed out and using less bandwidth. It doesn't take anyone to figure out the more bandwidth you use the more data you can push. The trick is to use less not more. That is the Amateur radio operators creedo. Apparently you forgot that part.

 

21, 24, 28MHz good for 48kHz bandwidth digital signals

Your insulting attitude is not appreciated and it does nothing to further the issue.

Just because one does not have the capability or knowledge to know when the 21-28MHz bands are open or not, does not mean that others don't have capability to use these bands freely.

For the past several years of low solar cycle, my friends and I have regularly made contact on 21, 24, and 28MHz when we see no other hams using these bands.

These bands are often empty simply because there are no hams using them. This is a perfect example of a wonderful situation to utilize 48kHz bandwidth HF modems.

 

ROS is built from the ground up as a weak signal mode. The fastest it can do is 16 baud, hardly a "fast" mode. It's simply not built to push high-speed data. It's shine and glory is it's one-baud mode, where its S/N makes it so high power simply isn't required. WSPR, another weak signal mode, rarely needs more than 5 watts to get through. Pushing anything more breaks the amateur code of using only as much power as required. Because of its low speed and therefore low power, it is possible for it to be well below the noise floor.

ROS isn't a mode that will be "pegging the meter" anytime soon. You most likely couldn't even hear if it you were scrolling through the bands.

 

What do you mean? Is the bandwidth greater than 2250 Hz?

 

The only one that is insult prone is you thinking your band hogging modes should be the only ones used on the bands. That is the way you think Bonnie and a lot of people think the same as me. You tried to push that garbage ARRL bandwidth proposal and a lot more hams pushed back and got the ARRL to pull it back. You just don't understand that the band is not in use only because the band is at a low peak. Back in 2000 when the solar cycle was good 10m was booming with signals all over the band. What are you going to do when you entrench yourself on the whole 10m band and the cycle gets better? Then you will complain about not having enough room for your band hogging modes.