Thursday, July 30, 2015

6 Meter E-season Wrap-up

Over the past couple of weeks the number and quality of sporadic-E openings has drastically declined. While there may still be a few good ones, for me this marks the end of the 6 meter season. The temporary small yagi I built and installed to get back on 6 has done what I intended.

In this article I will recap my brief return to the "magic band", now that it is coming to a close.

Statistics

First, the numbers.
  • Contacts: At least 100, but not counted. Most came in the ARRL VHF contest and the Es peak in late June.
  • Grid squares: 75+ worked, with over half already confirmed on LoTW.
  • DXCC countries: 11 worked, including Canada and the US. The other 9 ranged from XE to the southwest, several in the Carribean, and several more across the Atlantic Ocean. More countries were heard but not worked.
  • Continents: North America, Europe and Asia. South America heard but not worked.
I as satisfied with these numbers even though they are not impressively large. Some have reported the season to be below average. That may be true. Although I have lots of experience on 6 meters from years ago my recollection is fuzzy and my poor antenna tended to make every opening this season a poor one.

It was well worth the effort of putting up an antenna and wasting some nice summer weather closeted in the basement shack.

Antenna performance

Running 150 watts I am pretty well able to work what I can hear. I only wish I heard as much as others. Many DX and marginal openings allowed others in and near my own grid (FN25) to work stations I could not hear at all.

The poor performance I'm experiencing is a combination of a compromised antenna -- nestled close to the tri-band yagi -- living in a river valley, and noise level. There is no easy way to disentangle their respective effects, except to not they all limited my results.

I seem to do well on aurora scatter, mostly done aiming across and along the wide Ottawa River. The yagi is small and so has a wide beam width for scattering off aurora well above the horizon. I only suffered on the longer auroral-E paths to VE6, VE7 and KL7, which is more due to poor antenna gain. Stations in all these call areas were heard during one excellent aurora opening.

The same appears to be true for Europe since the northeast direction is unobstructed. It comes down to a matter of antenna height and gain, of which I have little. I was very happy to work the few Europeans that I could. There were others I either could not hear or could not work.

The big problem is south, looking into the hill I mentioned in an earlier article. XE was not a problem, which skirts the hill by aiming southwest. Caribbean and South America were the toughest DX paths. I was happy to work what I could, and dream of what I might have worked with a better antenna.

Noise

With a proper antenna I am able to hear noise much better than before. This is clearly not good. Getting the noise source off the side of the yagi helps, but that is unfortunately in directions with little to no activity. The is typically in the range of S3 to S7 at SSB bandwidths, and occasionally even louder.

I mostly kept to CW where a narrow filter usually cuts the noise to a managable level. The high CW activity on 6, more so than I remember back in the 1980s, made this strategy a successful one for me.

KX3

I use the Elecraft KX3 on 6 meters since the FT-1000MP is HF only. An outboard amplifier raises my signal from QRP to 150 watts. It can now update my earlier opinions of the KX3, which had focused on HF contests and DXing.

In sum, I am not too impressed with the KX3 on 6 meters. There must be some aspects of the DDS and receiver that are different than on HF. I did not delved deeper to discover the reason for what I observed.
  • Tuning artifacts: When the VFO dial is spun there is often a loud ratcheting sound as the DDS makes its frequency steps. It can hide the very signals you wish to hear. Sometimes I had to tune more slowly than I'd like The manual talks about this and suggests how to reduce the effect, but not eliminate it entirely. There are trade-offs. Maybe I'll try it someday as an experiment.
  • Single signal reception: In what is largely another tuning artifact, when tuning through the opposite side of zero beat, signals bleed through to the AGC. The effect seems less severe when not turning the VFO. The AGC pumping is worse than I've encountered on any of the HF bands.
  • Noise artifacts: When tuned to a reasonably loud signal it can often be heard to crackle (sizzle?). It is more apparent on a continuous tone (CW/carrier) than SSB, but it's there nonetheless.
  • Spurious signals: Disconnect the antenna and tune the band and I discovered perhaps a half-dozen spurious signals of significant amplitude between 50.0 and 50.2 MHz. Considering the receiver technology (direct conversion) these are not "birdies", so I label them as spurious. When I connect the antenna there are lots more to be heard, but those are not the fault of the receiver.
  • Noise blanker: The dreadful noise I am dealing with can be significantly attenuated by the noise blanker (NB). Unfortunately the NB also reduces signal amplitude and adds substantial distortion. Careful adjustment of the NB level can help, though in most cases I get better results with the NB off.
Despite all the negativity in the above list, the KX3 did the job and I still like it just fine. It isn't the greatest rig around, but then that is not its purpose. For a small, portable, high-performance QRP transceiver it does very well indeed.

Hurry up and wait

Years ago it was tedious work to watch for openings. Often when I was home I would leave the receiver tuned to 50.125 MHz (the domestic calling frequency) with the volume set low. If I heard something I might check it out for a potential opening. There was also WWV for the geomagnetic indices that could herald aurora openings. At the height of the solar cycle high solar flux readings promised real DX.

It's much easier today. DX spotting networks are available with any internet connection, including my smart phone. All I need to do is look for spots on 6 meters and judge whether it's worth going down to the shack.

Even so there is time and effort required for success on 6. Most openings on 6 are marginal: signals are weak and fleeting. If you hear something enticing you have to jump. Wait a few minutes and the opening or wanted station can be gone, and may not come back until next year, or longer. Listening isn't enough: someone has to transmit. Many times I would go down below 50.1 MHz and loop CW CQs with the antenna pointed in a likely direction. Someone will answer, eventually, if sporadic-E has been reported by others in my vicinity.

Other times it's tedious tuning of the VFO, with longer stops at every station or beacon spotted. This is not welcomed by those with busy lives, hams who can only operate when life allows and not when the propagation dictates. Be prepared for that if you venture onto 6 meters. The rewards are many, but then so are the sacrifices.

Next up

Temporary means temporary, so the 6 meter yagi's presence will last only a little longer. I expect that by mid-August the yagi will be taken down and stored in the garage until next year, or perhaps even later. My plans for 2016 are unclear.

The feed line I co-opted has kept me off 80 since early June. This was little sacrifice during the summer's high noise level and low activity on the low bands. The coax will likely be reconnected to the 80 meters antenna for at least a short time. I have plans for improved low band antennas before the contest season arrives. Those plans will be the subject of a future post.

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