2015-11-04

Active antenna

I have finally got my active antenna connected. This is an old Dressler ARA-60 that officially covers 100kHz (50kHz ?) to 60MHz with a substantial gain, and a decent dynamic range.

First things first. Using this antenna while transmitting does not work very well. No surprise there I have my 10m vertical about 5m from the active antenna, so it is, of course heavily overloaded when transmitting 100W on 10. All true signals simply disappear. No, I am not disappointed, I was expecting that, even with my 3W CW, that I use mostly on the HF bands with a dipole, overloads the amplifier.
Similarly, the medium wave broadcast signals tend to generate IMD in the receivers on frequencies below 500kHz. At least, that is how I interpret all the apparent spurious carriers on those low frequencies.
Also, I am not yet using the original power inserter (connectors have to be provided), so I am using a simplified power inserter with a high value inductor. This works fine on MF/LF, but, unsurprisingly the inductor appears to have some resonant frequencies, making the gain vary over the (large) frequency range. I suspect that when I get the correct power inserter ready that will change.

I am splitting the signal from the antenna into ~>49MHz and ~<30MHz, using a commercially available diplexer. The >49MHz signal is then entered into a broadband power splitter (3 outputs), going to scanner receivers. One goes to a multimode scanner, listening to beacons, meteor scatter from TV transmitters, SSB, CW etc. and the other to an FM scanner receiver. The <30MHz goes via a 4-way satellite TV signal splitter to (at the moment) a single HF receiver covering  ~0 - 32 MHz. Things work nicely, and I have good signals on all HF bands - noise level is rather high on some frequencies. On 600m the signals through the splitter are still quite sufficient, although there seems to be some IMD present. I expect to use this setup later for QRSS and WSPR monitoring, most likely with simple home made receivers.

It will probably be a good idea to split the frequencies further, e.g. with a low pass/high pass filter centered around 500kHz, in order to remove the MW band signals from the receiver for the lower frequencies.

Now, just listening, the antenna provided a nice surprise. The spec tells me that the antenna is good up to 60MHz, but the "local" beacon on 70 MHz (about 40 - 50km away) comes in nicely. The receiver set up for the 70MHz FM calling frequency of 70.450MHz suddenly came to life, and a station about 180km away appeared on frequency via tropospheric propagation (tropo).

All in all this is a nice generally applicable receiving antenna. The limitations are clear to me, but it presents a good compromise until I can improve the antenna system, and is good for general LF/MF/HF/6m/4m monitoring.

2015-11-01

10m in October

Late September I got my half wave vertical for 10m mounted with the feed point about 7m above ground.

This seems to have been good timing because that was about the time that the band started opening, at the time mostly in the North-South directions.
As October has passed, this has expanded to most of the world, and I have had the pleasure of working 6 continents. Antarctica is the one missing, it was active, but I could not get it. Maybe later.

As of today the country count is up to 56 in 6 continents on 10m alone. Not bad for a low Solar Cycle and a vertical. I suspect that, if the solar flux keeps up, we will have mostly daily F2 openings on the band until March/April. Several days we have had openings into the Mediterranean, i.e. down to about 2000km, indicating a relatively high MUF, albeit not enough to have 6m open. On 6 there is always the small hope of a few TEP openings around the Equinox.

I am now going to be listening to the low frequencies, especially during the dark hours which are aplenty here in the next few months - and probably try some low power work at the lower HF bands. After all, 10m is not very much open during those hours in the winter season of the current Solar Cycle, except for a few sporadic E openings in December and January.

I am still waiting for VK and ZL. I have heard them, but not yet being able to work them.

2015-10-19

10m in the Past Week End, or : Contest, a blessing and a curse.

The past week end  and today (Monday) 10m has shown it good side, propagation wise.

I was able to work into 5 continents : Europe (Doh ! - local), Asia, Africa, South America, and - finally, since I got re-started on radio activity, North America.

However, there was a down side this past week end : The Worked All Germany contest was running for 24 hours. This just means that Germans were not workable on 10m from here, and everyone else **only** wanted to work with German stations. 24 hours with essentially no contact possible.

Now, the up side is that it was absolutely "loud and clear" that 10m propagation was present all during the daytime, and a bit into the early evening. This is the advantage of having contests. Now, if the contest would have been everyone working everyone, I would have been really happy because I would have been able to participate fully on the band. I look forward to a week end with a non selective contest and good 10m propagation.

Oh yes, there *was* a non selective contest running, the Ten-Ten International QSO party or so, but that activity drowned completely in the big one, even on 10m. It was running 48 hours, but the activity in that one was very low, outside the German one.


2015-10-07

10 and 6 today : Aurora(l) E

So - today was a poor day for HF propagation, we have a major magnetic storm going on, so signals are down, bands closed or almost closed.

Well, even with my 3 band vertical for 6m/2m/70cm I could hear aurora signals for a little while. people not far away have been seeing the Aurora Borealis, a.k.a. Northern Lights.

Enter 10m : An otherwise closed band, it would seem, until a signal popped out of the noise, quite strongly. Local ? No, it came from Northern Norway (Narvik).

I was able to work a few stations in Northern Norway and Finland, I took to calling CQ for a while, and two OH stations came back. Not bad for an otherwise dead band.

Yes, I am aware that this can occur during auroras, so it is nice to see that there is also activity.

Morale : Never give up on 10m and 6m. Those bands have the magic of opening at unexpected times to unexpected places - well, sometimes.

2015-10-05

Antenna testing.

Today was the first time I tried out my RigExpert antenna analyzer. What a neat instrument.

I am in the process of tuning a multiband dipole for the HF bands. Still not finished, but using the analyzer to see the SWR curve (or Smith chart, or R and X) makes antenna construction so much easier.

The process is not yet finished, but I have, at least seen that I can operate in the full CW bands of 15 and 20m without an antenna tuner, and about 50 kHz of the 80m band as well. The rest is still to be adjusted. When the adjustment is complete I expect to be able to operate on the full 15m and a good part of the 20m band without using a tuner.

The antenna is a bit low in resonance frequency, probably because of the low height of the end points. I think that it will become possible to operate most of the 40m CW band without tuner. The rest of the old bands (80/40/20/15/10) will need the assistance of a simple tuner.

On the other hand, my 10m half wave vertical provided a rather interesting result. Two minimum SWR points on 27.7 and 28.6 MHz. I suspect that one is the real resonance frequency of the antenna, and the other appears due to some accidental matching provided by the cable length used. More test to follow on that. The end result is that the antenna is below SWR 1.5 from 26.9 to 29.7 MHz.

A very universally applicable antenna.

Later some more experiments are in order.

One thing I do want to test is making antennas less obtrusive. A shining half wave aluminium vertical is rather visible when seen on the background of trees, and when it stands on a surplus military mast (yes, green) it looks like it is floating in the air.

I am looking for a paint for metal antennas that will not deteriorate  the performance, at least very little. Any ideas. I will be looking up paint on the net in the next few days, but any input is appreciated.

For now I have a paint mix that should be tested with a simple 2m aluminium dipole, now that my test equipment is coming into operation, albeit slowly.

One more thing I have to look into, is guy wires that are less obtrusive than the white flag lines that are more generally available, along with having high strength and good insulation properties.


2015-09-30

10m activity

Today was interesting on 10m.

Got to the radio a bit earlier, and the band was open to the East with UN7 and similar.

Later more wide spread openings, worked into 7Q7 and Z21, 4Z4, EX8. Heard VU2, 5E (Morocco), 4J, ZD7.

The half wave antenna works nicely. I still want to improve my 10m capability before winter, if possible.

2015-09-29

10m activity

Looks like 10m is really waking up now.
After yesterday with very little activity I had some activity most of the afternoon here. QSOs into ZS6, UN7, 5E (Special event station in Morocco) and 4J3. The UN7 called me on my CQ. Then there was a local OZ, just e few km away.

Further heard were A93, 4X4 and CX. meaning that I had QSOs with 3 continents and heard a 4th.

Yes, 10 is really waking up.

Just shows that my own CQ calling activity helps, at least for me. the last few days I have been calling CQ for up to more than half an hour, so yes, it takes some patience ...

Now for improving my own 10m signal. What to do ? A rotating beam is not in the planning, I would reserve that for VHF/UHF (6m/4m and up). The other options will be elevating the feed point of the antenna, or find a vertical with more gain. There exists a combined 6m/10m antenna, 5/8 on 10 and 2x5/8 on 6m. The gain on 10 would probably provide me with 2dB more signal, probably in effect a bit more due to a lower radiation angle. other option could be vertical stacking or making a collinear antenna.
Fixed wire beam ? A possibility. If I could find a 9m or higher support point it may be possible to make a Double quad element, possibly with a few reflectors, creating a low hanging "Hybrid Double Quad" (Design by DL7KM). This could provide some decent gain of about 8dB if high up. I wonder how it will work in such a low height.
A simple fixed direction 2 element quad antenna. Not too difficult to construct, and should have a reasonable effective gain, even at such a low height. Probably worth looking into.

Power amplifier ? Not the option I am looking too much for, my 100W have done reasonably well with the present vertical - and it has no effect on reception.

Other ideas ?

2015-09-27

10m activity - or lack thereof.

A few days ago I installed a vertical half wave antenna for 10m in the garden. It was moved up a bit yesterday, and immediately, at the first test, I worked into South America (CE). OK, 10m has improved since the late summer doldrums, but it was a surprise to get a reply from a not too strong station on F2 propagation, even if I used 100W this time.

This week end there has been a RTTY contest on the HF bands, and here is the point : 10m had signals coming in for several hours, QSB and all, some of them approaching S9. However, the only signals I heard on 10 CW today were PY2XC and one other PY, not nearly as strong as the RTTY stations. Yes, I realize that the RTTYs were contest stations with high power and big antennas, yet, if I recall correctly, PY2XC is not that small a station, either.

This leads me to one inescapable conclusion (one that should not surprise anyone) : 10m is open much more often than we discover, because of one simple problem - people think there is no propagation, and therefor do not even *TRY* to call on 10m - and, as we all know : Listening to another station listening is a poor way of making contacts. It is a vicious circle : No contacts, so no activity, so no contacts, etc... So, today I programmed my memory keyer and tried some CQ calls in 2 15-30 min periods of the afternoon - for now with no QSOs.

OK, now that I have a decent antenna for 10m I am planning to try the good old fashioned CW CQ method, especially in this winter season, because it might be the last good winter season on 10m for a *long* time. No one knows how long ...

I would probably also see if there is any local FM activity on or near 29.600.

I intend to do something similar on 6m, especially at the beginning and end of the sporadic E season.

Also, I intend to monitor 27MHz for possible propagation, there seems to be some SSB activity on 27.555, so a receiver on that frequency is in the planning. Yes, one more antenna ;)

So there we are, look for me between 28.020 and 28.030 when the band looks like it could be open. In the evening I may try to be on 29.600 or there about. Later I should become set up for digital modes on 10, probably some WSPR during my not-so-radio-active periods of the day.

The other thing to look for will be 10-10 members to make QSOs with. There are some QSO parties in October, so I am hoping to get to some of those.

I am looking forward to learning more about 10m propagation as I go.


6m activity

Since my move back to Denmark I set up (the cable to) an old 3 band vertical for 70cm/2m/6m.

This antenna has been used mainly for local FM on 2m/70cm.

On 6m it has been used occasionally with a IC-706 TRX running SSB and (mainly) CW on 6m. Because I got going late in the Es season not so much has been worked. Next year should be better.

Hearing stations (not workable at that moment) from 4X4 and EA8 have been the highlights. Mostly a few station in Europe worked on 6 in the late summer, mostly with CW. It took me a while to find my memory keyer, so that's why.

A better 6m antenna is a must here. Probably before the Es season next year. All antennas needed a lot of maintenance after more than 20 years of dis-use, so things are slowly getting there.


2015-09-26

Antennas

Got myself moved safely back to Denmark, and got a bit of antennas in the garden.

 1) 3 band vertical for 6m, 2m and 70cm. Worked local on 2/70FM, and a bit of sporadic E this summer on 6m.

 2) Lately I got myself a multi-dipole for 80/40/20/15/10. Works on 30/17/12 as well. SO I got started doing a bit of CW QSOs ...

 3) Decided that 10m might have it last really good winter season, so I set up a half wave vertical (shortened 27 MHz Half wave). Just moved it into the garden and elevated the feed point to about 5m. Came in late in the afternoon and 10 was open to South America and South Africa. Worked CE, CX, ZW (ZS) and PY. Not bad for a first day with the new antenna. Given the opportunity the feed point will get up to about 7m with some good guy wires.

 Winter is coming, and I would like to try getting a bit more antennas up, possibly for 4m, and a wide band receiving antenna (active whip (Dressler) or a PA0RDT "mini whip" E-probe). This should work from <100kHz to about 30MHz, the Dressler claims 60MHz).

2015-03-14

Activity form OZ9QV

Welcome to the OZ9QV blog. Later this year the OZ9QV site will become radio active again. The intention is starting slowly with a single vertical for 6m/2m/70cm, and a dipole for HF. Simple, but a start. Long term the intention is to extend the activity to 50/70MHz SSB/CW etc. - as well as some QRSS monitoring activity. Do not expect a lot of blog activity the next several months, but some more near the end of the year. 73, and BCNU (Be Seeing You)