AmateurRadio.com

As someone who has quite often used WSPR, I have often said that it would be nice to be able to exchange reports with other stations and confirm the “contact”. I felt this simply because the WSPR network is a friendly community and it feels right somehow to be able to do that, just as you would confirm an enjoyable contact on another mode.

Modes like the little used WSPR QSO mode and JT65A on HF offer the chance to make two way QSOs using similar power levels to WSPR. But my recent experience using JT65A on HF, and more recently watching a station in Iceland take half an hour to try to exchange a signal report and confirmation with a station in Brazil using a certain other weak signal mode led me to wonder if in trying to make it possible to make “contacts” using the least possible power we have thrown the baby out with the bath water.

Communicating via moonbounce (EME) on VHF has always been about exchanging the barest minimum of information, because even doing that is a major achievement. But on HF it is always possible to have a proper contact, even if it means using a bit more power or waiting until propagation is a bit better. So why are we endeavouring to use modes designed for EME on the HF bands? What is actually being achieved? Someone’s computer is able to pick a few characters of information out of my barely audible signal, with the help of heavy error correction and the fact that the message format is known. My computer is able to do the same with his. Is this actually a contact?

Yesterday I tried for the first time in several years to use the Olivia digital mode. Before I did, I Googled up some information about it, and came across a Yahoo group containing a post by Waldis, VK1WJ. He wrote: “Yesterday I had a sked with DJ2UK on 20m in JT65A. Bert came in with around -17dB but he couldn’t decode my signal. After a while I saw in SPECJT that he had switched to Olivia 8/125. So I did the same, and we had quite a long error-free QSO. Olivia 8/125 is not exactly fast, but it still beats JT65A hands down. May be we could entice our JT65A friends to try Olivia instead?”

According to Waldis, instead of exchanging a couple of numbers using JT65A, you could have an actual (if slow) conversation using the 8/125 variant of Olivia. But the JT modes are currently in vogue, whereas Olivia – being developed in 2003 – is yesterday’s news. People are raving about the capabilities of a certain other mode that is making a lot of news recently. Have all these people actually tried some of the forgotten modes? Because I think if they did they might wonder what all the fuss was about and whether the newcomer really justifies its use of bandwidth.

What was I saying about reinventing the wheel?

Today I spent a couple of hours making some contacts using the Olivia digital mode. It isn’t the first time I have used the mode. I used it several years ago back when I used the MixW software. I seem to remember that it produced good copy even when using 5W from my K2, but it was hard to find other people to QSO with. But now there seems to be plenty of activity. Olivia even has its own website.

Although using Olivia is much the same as using PSK31, using the same software, it has quite a different feel. As with PSK there are different versions of Olivia. I was using Olivia 32/1000 which on 20m is normally found around 14.106MHz. This mode is 1kHz wide and operators use USB with the suppressed carrier frequency on an exact 1kHz multiple, e.g. 14.105, 14.106 or 14.107. The center frequency of the waterfall is set on 1500Hz, so the audio tones are generated between 1 and 2kHz, which is in the center of the passband with most radios. If you do this and your rig is accurately calibrated you should hear anyone who calls on that frequency without any need for re-tuning.

Olivia 32/1000 prints out slower than PSK31 which makes for nice relaxed contacts. People tend to chat using the keyboard instead of exchanging macros, though they may use a macro for the basics. Olivia uses forward error correction, so you may not see any print for several seconds after a transmission started and it may not finish printing until after the transmission stops. But the copy is usually 100% perfect even when the signal dips into the noise so you can barely see it in the waterfall. I swear I’m not biased but I thought Olivia performed much better than another mode that is no longer mentioned by name in G4ILO’s shack and is more than twice as wide.

My first contact was with Andri VE2AHS in Ottawa which was 100% perfect copy throughout. I don’t believe I would have made this contact using PSK31 at the same power level (25W into my attic dipole) nor do I believe I would have had such good copy using the other mode.

After lunch I was called by Fred OH/DK4ZC. Fred is very interested in digital modes and was apparently involved in trials of Chip – a mode similar to the latest one – with Nino, IZ8BLY back in 2004. He told me the trials were abandoned as the results were poor. He asked me what I thought of the new mode and of course I told him. Fortunately my K3 has very robust cooling and can withstand long periods of operation in continuous duty cycle modes. 🙂

Next I had a 40 minute chat with John, W9CY near Peoria in Illinois. Again, it is just unimaginable to have such a long ragchew with the USA using any other digital mode. John had heard interference from a strange new mode recently and asked me if I knew what it was so the K3 PA got another warm-up as I filled him in on the details. In fact, some fairly strong QRM from the unmentionable mode did appear during one of his overs but although I did lose a few words Olivia survived the interference pretty well, and better than the new mode survived Olivia.

Finally I was called by Adriano, IZ1PSS, who informed me I was his first contact on the Olivia mode. He had a good strong signal so I left him the frequency as I had been on the air for quite a while by that time.

I really enjoyed my session using Olivia – so much so that I intend to spend a lot more time in future using the mode. The ability to hold long rag-chew keyboard QSOs with near-perfect copy over long distances using relatively low power and an indoor antenna isn’t something that I thought I could do. We hams seem rather good at trying to reinvent the wheel when we already have several perfectly good ones that we hardly ever use.

See you on Olivia!

A K3 is for sale on the Elecraft reflector by Dan in Florida, who gives the reason for sale as “large unexpected medical bills.”

I’m sorry for Dan and hope my linking to his ad from here will help him to get a good price for his radio. And I thank God that here in Britain we have a National Health Service!

Dear Sirs.

I understand that the trend in amateur radio these days is towards self regulation. However, recent events in the digital sub-bands lead me to believe that this is just a recipe for chaos. I refer to the recent appearance of ROS, a 2.2kHz wide digital mode apparently developed for weak signal work.

Soon after the ROS software was made generally available, chaos ensued with ROS users causing interference to IBP beacons, established APRS and ALE networks and Olivia users, not to mention other ROS users. Any chances of making DX low-power contacts were dashed by the number of people trying to use a limited number of frequencies to make short range QSOs that could have been accomplished using PSK31 and one twentieth of the bandwidth.

The band plans do not set aside specific sections of the digital sub-band for different modes. I am told that this is so as not to hinder experimentation. However, many popular modes such as PSK31, WSPR, Olivia etc. have established their presence on various parts of the bands and this is normally honoured by “gentleman’s agreement.” This all goes out the window when someone posts on the net that a new mode is available and hundreds of people download software and go mad with their new “toy” without any authoritative guidance as to where to operate.

The experience with ROS throws into question whether different digital modes can co-exist in the same band space. Many digital users seem to treat signals in another mode as QRM to be transmitted over rather than somebody else’s contact. The problem in the case of ROS is exacerbated by the fact that the transmission of this mode is 2.2kHz wide, which makes it harder to avoid causing interference to somebody. I think we should also be asking if there ought to be a limit on the width of digital modes that can be used on the HF bands, because there just isn’t enough space in the digital sub band for many people to each have a clear 2.2kHz wide channel.

I am not against experimentation, and would suggest that a small part of each band be set aside for experimental modes, experiments being conducted by the developer and a few chosen testers. However, before a mode can be made available for general use it should be approved by an international committee which would take into consideration the benefits of the mode, the amount of bandwidth it occupies and what frequencies it may be used on.

Julian, G4ILO

CC: Andy Talbot, G4JNT, Data Modes columnist

I visited the ROS Digital Modem Group on Yahoo! and found the following message:

ROS ULTIMATUM

Several hours ago I posted about the news that the FCC had reversed its decision regarding the legality of the use of ROS in the US. Is that not good enough for him?

A week ago, when I posted that ROS was illegal in the US, that was what the FCC believed and what I wrote was true at the time. I am not in the Soviet Union and I am not rewriting history to suit someone else’s convenience. Moreover, if someone has an issue with me or anything I write, would not the correct way to proceed be to send me an email, not issue an ultimatum in a public forum that I may or may not read?

I am so angry I can barely type.

Update: Jose has now seen my post of this morning and issued an apology. He wrote:

I apologize and I hope you put yourself in my place and understand my indignation.

I don’t wish to have any ill-feeling so I have accepted his apology. But I am still pretty angry and upset about the manner in which he chose to express his indignation. Even if I hadn’t yet written about the changed ruling, an email would have been all that was needed to obtain my assurance that I would as soon as I could.

I will not be using the ROS digital mode any more.

José Alberto Nieto Ros, the developer of the new ROS digital mode, has submitted the technical specification of the mode to the FCC, as a result of which they conclude that ROS can not be viewed as Spread Spectrum and would be encompassed within the section 97.309 (RTTY and data emissions codes).

Now, all that needs to be resolved is the issue of where to use it without causing complaints from users of existing nets and other modes. Anyone with experience of getting quarts into pint pots please apply now.

Kevin, GW0KIG, has just written in his blog about struggling to brush up his Morse. He first learnt the code at the age of 19 and has “memories of a Morse code tutor program on a borrowed ZX81 computer (remember those?)”

I remember the ZX81 and its wobbly 16KB RAM pack very well. In fact, a Morse tutor was one of the first programs I wrote for it. I wrote an article for Short Wave Magazine which described the program, together with a Morse keyboard with programmable memory and a high-speed Morse sender for meteor-scatter work. It is amusing today to read my conclusion that “it is possible to program the ZX81 to create sophisticated memory keyers.” These primitive programs would hardly seem sophisticated today.

The article was published in the August 1982 issue of Short Wave Magazine. I kept a copy and you can see it here. I wonder if my program was the one Kevin used to learn Morse when he was 19? One of these days I might try downloading a ZX81 emulator and see if these old programs will run on it.