AmateurRadio.com

Photograph 1 depicts our first attempt at helically winding 97 feet 1 inch of AWG#14 wire on 2 inch PVC SCH40 before re-thinking our strategy. I opted for removing the long screw driver on the wire spool and approached our problem like taping a piece of pipe. I maintained upward and downward tension using the spool.

Photograph 2 facilitated third person in this operation because handling a 10-foot piece of PVC is difficult to balance while winding.

Photograph 3 demonstrates our solution in addition eight inch lengths of halved duct tape at every 12th or so wind. We found taping at this interval suitable enough to maintain adequate tension. I attempted, to the best of my ability, half inch spacing between winds however I’m not satisfied with the quality of my work. Therefore, the next step in our project, includes adjusting each wind accordingly.

Photograph 4 illustrates the end result of three hours of labor. My plan is to replace the spade located at the binding post while spacing each wind according to K6MM’s instructions. We divided each each section by the total length that is 256 feet 5 inches of wire equaling an average of 85 feet per section. Additionally, I’m purchasing alligator clips for each section because I’m intending to deploy the antenna in the portable mode.

Believe in your signal!

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!

Welcome to Handiham World!

As we head into the longer daylight hours here in the Northern Hemisphere, band conditions will begin to favor the higher frequencies of the High-frequency (HF) spectrum and thunderstorm static and absorption will get worse with more hours of solar energy hitting the “D” layer of the ionosphere. HF radio waves are not reflected by the D layer but do lose energy as they pass through.

As explained by Wikipedia, “This is the main reason for absorption of HF radio waves, particularly at 10 MHz and below, with progressively smaller absorption as the frequency gets higher. The absorption is small at night and greatest about midday. The layer reduces greatly after sunset, a small rest remains due to galactic cosmic rays. A common example of the D layer in action is the disappearance of distant AM broadcast band stations in the daytime.”

This, of course, means that amateur radio operators will have to stay up late into the night to make contacts on bands like 160 and 80 meters once the long days make those bands difficult to use for all but a few hours out of 24. That same solar energy heats the ground, causing convection and building thunderstorms that make those same bands crackle with noise all summer long. On the plus side, the conditions are still acceptable on 160 and 80, so you still have some time to collect some DX contacts. Don’t wait too long though, because the days are getting longer by a few minutes each day. (Exactly how many minutes depends on your location.)

Fortunately, 20 meters is coming back to life and will improve with the upcoming season. Sunspot numbers are up. Today, we see four groups: 1045, 1051, 1052, and 1053. Higher sunspot numbers are associated with better long distance propagation conditions on the higher frequencies of the HF spectrum. 20 can be a crowded band, but soon 17, 15, 12, and 10 will open up for DX and the fun will really begin for a lot of our newly-licensed Generals. These operators have never experienced the fun of a solar maximum!

When conditions are good on 14 mHz and above, you can work great distances with low power and surprisingly simple antennas. Even that plain vanilla wire antenna that never seemed to hear much of anything on 10 meters can come to life with DX. Mobile antennas can be used to work the world. QRP, or low power operation, becomes practical for daily use. Furthermore, because the length of an antenna like a vertical or dipole is inversely proportional to the frequency at which it will be used, the return of the higher frequencies means that you can perhaps finally fit a shorter, but highly effective, antenna into limited space. A dipole for use on 3.925 mHz is around 120 feet (37m) long, whereas a dipole for use on 28.310 mHz is only about 16 and a half feet (5m). This makes balcony and attic antennas practical.

As conditions begin to pick up on the 10 meter band, Handiham members who hold Novice or Technician licenses can take advantage of SSB phone operation between 28.300 and 28.500 mHz. Since most will be Technicians whose only experience on the air will have been with 2 meter FM repeaters, it will be a fantastic change for them – and a lot of fun! Imagine not having to depend on a repeater to talk to other stations far from your own location. Imagine not having to wait for drive time to be over before you can use a repeater. Imagine being able to tune with your VFO up and down the band instead of being stuck on a single repeater frequency. Imagine making new friends around the world and collecting QSL contacts for Worked All States and DXCC.

With the additional fun comes new responsibilities. Working the HF bands is different than repeater operation in other ways that newcomers might not realize. For example, while a repeater is silent for a period of time, that means that the repeater is not in use and you can usually just throw out your callsign to look for a contact. On HF, just because you don’t hear anything on a given frequency does not automatically mean that the frequency is clear. In HF operation, you may not be able to hear both sides of a QSO because of propagation conditions. If you just grab the frequency and start calling CQ, you may be informed that the frequency is already in use! On HF you have to listen even more than usual, and once you are fairly sure the frequency is probably clear, it may be prudent to ask, “Is this frequency in use?”, after which you give your callsign.

Another difference between repeater operation and HF is that you can generally count on being able to complete the contact on a repeater, because the system is set up to maintain solid copy as long as both stations remain in the repeater’s coverage area. On HF you can begin a QSO with excellent copy, only to find that changing band conditions suddenly cause you to lose the other station or sometimes cause other stations to “skip in” from far distances and cause QRM. Under such conditions, you have to be sure to trade essential information about yourself and your station before conditions change.

Contests are another feature of HF operation that will be new to those who have cut their teeth on repeaters. On contest weekends, the band can literally fill with stations eager to rack up points, making it either really hard to enjoy a long QSO with a friend or, to make the best of it, a fun way to make a lot of contacts and improve your operating skills. You can find out what contests are going on at any given time by visiting ARRL.org and following the “Operating Activities” link.

So to those of you who have not been on HF, let me extend a warm welcome to a whole new kind of operating. We are going to have a lot of fun in solar cycle 24!

For Handiham World, I’m…

Patrick Tice, [email protected]

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