Podcast: HF Propagation Report, September 2010

Report for September 2010 with a look at how solar cycle 24 still isn't going too well and why HF conditions will now start to improve in September and October. Just click on the Podcast headline above or search for G0KYA on iTunes.

HF Propagation, September 2010

Note: You can find Steve's HF short-path propagation prediction charts from the UK at:

http://www.infotechcomms.net/propcharts/

Solar conditions still continue to be fairly poor. As I write this on 3 September there are sunspots, but the flux is stubbornly in the mid to high 70s. There have been auroral conditions over the past few days and we can expect to see more unsettled conditions as the cycle progresses.

Having said that, conditions are improving due to seasonal variations. We are heading away from the summer solstice and towards the equinox. The ionosphere is cooling down and its chemistry is changing. Traditionally late September and October are good times and we can expect to see increasing DX being worked.

In some respects this has already started to appear. There have been some good 20m openings from the UK to the West Coast of the USA and Alaska, plus openings to the Far East.

Given the lowish solar flux I think we will continue to see 20m (14MHz) and 17m (18MHz) as the “money bands”, but don't write off 15m (21MHz) which will open to DX, but perhaps not as often as the lower bands.

Late September will be the acid test – and with flux levels in the 70s we are unlikely to see many (any?) trans-Atlantic openings on 10m. Sorry - I would love to be proved wrong!

Now let's look at each band and what you can expect.

The equinox periods provide longer daytime periods than winter, but logically, shorter night-time periods too. These tend to be the best months for working North-South paths, such as UK to South Africa and South America.

On 160m (1.8MHz or Top Band), look for short-skip and DX openings at night. Again, no daylight skip is possible due to absorption, but openings out to 1,300 miles and occasionally further afield can be expected at night with conditions peaking around midnight and again at sunrise (greyline).

80m (3.5MHz) will generally follow the characteristics of Top Band at night, but will also provide good openings out to around 250 miles during the day. These will lengthen to around 500-2,300 miles at night with fairly good DX opportunities at times. At this point in the cycle 80m should still provide good DX around midnight as absorption is still quite low.

40m (7MHz) Forty metres should open to DX in an easterly direction at sunset. Openings to the west should be possible after midnight and should peak just before sunrise. Contacts should be possible during the day, although lower critical frequencies may mean that it is difficult to work other UK stations while perfectly possible to talk to European stations. If the flux rises then 40m may open up to NVIS contacts around the UK.

20m (14MHz) is likely to be the best DX band between sunrise and sunset. The bands may occasionally open after dark, perhaps to the southern hemisphere. Good openings will be possible during daylight hours out to around 2,300 miles.

17m/15m (18MHz/21MHz) should provide fairly good DX openings during daylight hours, especially to Africa and South America, with 17m being open more often than 15m. Once again, 15m may struggle to open during times of low solar flux, but could provide good openings if it rises above about 90-100. Both bands are likely to close after sunset, at least later in the month..

12m/10m (24MHz/28MHz) These could be disappointing bands if the solar flux remains low. If the solar flux heads towards the high 80s/90s then openings will occur on both bands, although 24MHz will open first. If it breaks the 100 mark then expect to see some good DX openings on 10m, especially in late autumn.

You can find HF short-path propagation prediction charts from the UK at:

http://www.infotechcomms.net/propcharts/

You can also listen to Steve G0KYA's HF propagation podcast on iTunes or at http://www.g0kya.blogspot.com/

Steve G0KYA RSGB Propagation Studies Committee

The Western HF-10 multiband dipole

Latest News, 15-3-17: Fred is still making the antenna. He said: "Steve - I am still making the HF-10. I did stop for a while due to an illness. I don't sell them any more on Ebay. I can't keep up with demand. What I sell now comes through word of mouth. The price is £85 including special delivery."
You can contact Fred via m0bzi@outlook.com

The Western HF-10 multiband dipole was born out of Fred Western M0BZI's attempts at working 80m from a small garden. His basic design starting point was the half size G5RV, to which he added inductors on each leg. Unhappy with the results, he then played around with the overall length and added a balun at the feedpoint.

The end result is the antenna as now supplied.

Specifications

The Western HF-10 is a 67 feet long dipole/doublet. It incorporates two loading coils placed towards the end of the legs and has a 15 foot 3 inch section of 450 Ohm windowed ribbon feeder to the centre feed point. At the end of the 450 Ohm feeder a ferrite rod balun is fitted for the transition to 50 Ohm coax. This appears to be wound as a 4:1 impedance transformer.

The build quality is excellent and all fittings are stainless steel. The balun housing is substantial and all crimped joints are very strong and designed so that they don't stress the antenna.

The antenna wire is Flexweave, which is both strong and easy to work with.

Installation

For the test I installed the antenna an an inverted V with the apex at about 30ft and the ends at about 10 feet.

Out of the box the antenna was found to be resonant at 3.7MHz.

Initial SWR tests were done using a 15ft length of RG58 coax to an MFJ analyser. Subsequently, a further 60ft of RG213 was added to bring the end into the shack. The subsequent SWR readings with the additional length of coax are shown in brackets.

SWR measured with MFJ 269 antenna analyser at end of 15ft RG58 coax (and at end of 60ft RG213 coax)

1.9MHz: 31 (10.8:1)

3.5MHz: 3.7:1 (5.5:1)

3.7MHz: 1.2:1 (1:1) resonant point

3.8MHz: 4.3:1 (3.9:1)

7.0MHz: 6.2:1(3.3:1)

7.1MHz: 6.2:1 (3.3:1)

10.1MHz: 6.1:1 (3.2:1)

14MHz: 2.5:1 (1.6:1)

18.1MHz: 4.8:1 (2.7:1)

21MHz: 4.6:1 (2.3:1)

24.9MHz: 3.6:1(2.3:1)

28MHz: 1.2:1 (1.2:1)

29MHz: 1.9:1 (1.4:1)

50MHz 1.7:1 (1.5:1) – actually resonant at 48.6MHz

As can be seen, the SWR appears to go down once the additional coax is added. This is normal and is due to losses in the coax. Out of the box the antenna is naturally resonant on 80m, 20m and 10m.

The internal ATU on my Icom 756Pro 3 was able to find a 1:1 match on all bands 80m – 6m quite easily. Fred had said that his Yaesu FC-902 was also able to match the antenna on 160m, but the SWR was outside of the tuning range of my internal ATU.

Nevertheless, my external ATU was used to find a match on 160m, despite the antenna's short length.

First impressions

The antenna was mounted away from the house and fed via a 10 turn coax choke balun. This, plus the antenna's own balun resulted in a very quiet installation from a noise point of view.

With today's electrically noisy urban and suburban environments this was a breath of fresh air and made it that much easier to hear weak signals. The balanced design meant that there were NO detectable currents on the braid of the coax at all.

I had my doubts about the design of the antenna. It is very hard (if not impossible) to make a multi-band dipole that is coax fed and that will work on all bands. The Off Centre Fed Dipole (Windom or OCFD) is one design that gets close, but other designs (including the G5RV) fail to give a good match on all bands.

The problem is that they often display poor matches on many bands. The resultant poor SWR is often masked by coax losses on long runs, giving apparent better SWRs in the shack at the expense of losses in the coax caused by high SWR. This is why I did the initial SWR tests using a short length of coax.

Louis Varney G5RV himself also experimented with baluns at the open wire feeder/coax junction but abandoned the idea as the varying reactance at that point can lead to balun saturation and more losses/poor behaviour.

So I was interested to see how this model performed.

Performance

160m

I was able to tune the Western HF-10 on Top Band using an external ATU. The SWR is way too high for an internal ATU to match it on that band. Despite the antenna's short length I was able to work and hear UK stations, but signals were well down, typically around S5 compared with S9+10dB on my Windom (which itself is too short for Top Band). Nevertheless, if you only have room for a 67ft antenna it will let you experience the band. Noise levels were, once again, very low.

80m

The antenna's 80m performance was compared with an 85ft W3EDP and a 135ft home made OCFD (Windom) with a 4:1 balun, both with an apex at about 30 ft. I know exactly how these perform, having been using them in the RSGB's 80m Club Championship for three years. Best 80m DX on the OCFD has been VP8 Falkands and numerous US stations.

The antenna's noise level on 80m was found to be about three S points better than my existing antennas. This was because a) the Western HF-10 was situated further away from the house and b) it has an effective isolating balun. 

The offset nature of my OCFD means that it is prone to picking up noise on the feeder, despite a choke balun.

Signals from around the UK and Europe were generally found to be equal to or 1-2 S points down when received on the Western. This was to be expected as the antenna is only half the length of the Windom. The lower noise level however made it easier to hear people.

These results were fairly consistent – the difference was always between 0 and 10dB down. This isn't as bad as it sounds – signals that were S9 +20db on 80m might become S9 + 5-10dB. It was only very weak signals that were marginal. 

The low noise levels did make for easier listening though. I received a 59 +20db report from MJ0CTR in Jersey - what more could you ask for? At the time of testing (August) no 80m DX was heard.

40m (7MHz)

It was a similar story on 40m. EU signals were in general 1-2 S points down compared with the 136ft OCFD/85ft W3EDP, but lower noise levels made for easier listening. Some signals from DL were the same signal strength on all the antennas. Some were actually stronger on the Western.

30m (10MHz)

Again, lower noise was the order of the day. My OCFD is not really optimised for 30m and the Western outperformed it by up to 2 S points on CW around EU. A good antenna for this band. 
 

20m (14MHz)

Signal strengths from Europe were roughly equal to the other antennas. This was apparent on many signals and was not a one-off. Some signals were stronger on the Western by up to 2 S points. Tests with stations in VO1 and VE9 on 14MHz showed the antenna outperformed my existing antennas. This was the case too with a short skip contact with Jon GM3JIJ on the Isle of Lewis. This antenna really shines on 20m.

17m (18MHz)

Signals were once again roughly equal to my OCFD, but sometimes up to 2 S points weaker than on a dedicated 17m dipole. Noise levels were once again better. Switching between the two you could see the effects of polarisation shifting in the ionosphere as one and then the other antenna became louder.

15m (21MHz)

My Windom does not really work on 21MHz. I normally switch to the W3EDP or use a 40m dipole. The Western outperformed both.

12m, 10m, 6m (21MHz, 24MHz, 28MHz and 50 MHz)

I managed to find a few Es signals on 10m a few days after I wrote the original text. They were all down about 2-3 S points on the Western compared with a dipole and the Windom.

General Coverage

I couldn't help but try the antenna out on the Broadcast Shortwave/Medium Wave bands. It was capable of picking up BBC Radio Wales from Washford in Somerset on 882kHz in daylight hours ( I live in Norfolk), although my other antennas were louder. 
 

All of the stations I heard on the 7MHz, 9MHz, 11MHz, 15MHz were roughly all the same signal strength on both antennas. All India Radio on 6280kHz was down 20dB compared with my Windom.

Update: March 2014 
This review was written a couple of years ago. People have asked about the antenna's 60m (5MHz) performance. Although I didn't test it at the time the consensus from other people who have contacted me is that the antenna doesn't work well on this band.


Conclusions

I was very impressed with the Western HF-10. My first reaction was that it must be a bit of a compromise as it is only truly resonant on 80m. And yes, signal strengths were down a little overall. But the low noise characteristics of the antenna, and the fact that it could be persuaded to match on all bands 160 - 6m made it very usable.

On 20m the antenna matched or bettered my others in terms of performance, but with lower noise, which was a bonus.

You obviously trade off some performance on some bands compared with dedicated dipoles for each band, but this was never more than about 2 S points at worst (apart from Top Band). However, the low noise characteristics make up for this as I was often able to hear signals on the Western that were in the noise on my other antennas.

Given that these were also longer it shows how useful the Western HF-10 can be, especially if you do not have room for a full 80m antenna.

It also worked well on the shortwave broadcasts bands above about 4MHz.

For someone looking for an antenna that will fit in a small back garden, but will allow them to work all the HF bands, the Western HF-10 has a lot to offer.

Fred sells these antennas on Ebay or you can contact him via m0bzi@outlook.com

Night of nights, 13th July 2010

Every year maritime stations in the USA commemorate (not celebrate!) the closing down of the use of Morse code for maritime traffic. This happens on 12th July each year, going on to 13th July in Europe and eastward.

Known as "Night of Nights" stations like KPH and KSM in California, plus WLO in Alabama transmit on the HF maritime bands, and some, like K6KPH, transmit on the amateur bands.

Being stupid, I thought I would set my alarm for 5am on the morning of the 13th July and see if I could hear anything - I wasn't very confident.

VOAProp suggested that 8MHz offered the best shot and as it turned out I heard KSM in Point Reyes, California on 8.438MHz, WLO in Mobile, Alabama on 8.658MHz and NMC in California on 8.574MHz.

I listened on 80m, 40m and 20m but heard nothing, other than a lone W station calling K6KPH on 40m.

KSM/ K6KPH broadcast regularly and can be heard in the UK, although they are always weak with me at this point in the solar cycle.

Its nice to hear CW being used on these bands again. You can find out more from the Maritime Historical Radio Society web site on http://www.radiomarine.org

HF Prediction Podcast, Summer 2010

Report for Summer 2010 with a look at how the MUF stays high after dark, how to interpret sunspot numbers and how to use the solar wind indicator on solarcycle24.com. Just click on the headline above or search for G0KYA on iTunes.

HF Propagation and charts - July 2010

Solar conditions continue to be fairly poor. As I write this on 1 July there is a solitary sunspot (number 1084) which has pushed the solar flux up to 75, but this is nothing special. Strong southward-Bz-pointing solar winds are also causing the K index to rise at times causing havoc.

The sunspot number is currently 11. This doesn't mean there are 11 sunspots – you get 10 for each group and one for each sunspot. So one sunspot in one group (naturally) leads to 10+1 =11.

Some people have suggested that the bands are improving, but I think they are confusing Sporadic E (Es) openings with F layer. This seasonal effect is opening up 20-10m and even 6m and 2m with good, strong openings up to 1,300 miles.

Multi-hop Es is stretching this even further, but we are not seeing an improvement in F layer propagation and Es will be less prevalent as the summer wears on.

Mid-to-late September will be the acid test – and with flux levels in the 70s we are not going to see many trans-Atlantic openings on 10m. Sorry!

In summer, Daytime MUFs are likely to be lower than those of winter. But night-time MUFs may be higher in summer than those in winter, so check 14MHz after dark for some nice surprises. Greyline around sunrise in summer can also be good – Peter M0RYB worked Hawaii on CW using a vertical half wave dipole for 20m that he is testing the other week.

Now let's look at each band and what you can expect.

On 160m (1.8MHz or Top Band), high levels of static and solar absorption mean that the band will not really support sky-wave contacts during the day. During darkness, short-skip openings may occur, but DX may be a rarity. Occasional openings can occur during the hours of darkness, especially around local midnight/early hours.

80m (3.5MHz) will generally follow the characteristics of Top Band with high levels of static, but will also provide good openings out to around 250 miles during the day. Absorption will grow to a maximum at midday for inter-G contacts. DX capabilities will be poor to fair during the hours of darkness.

40m (7MHz) will suffer from high static caused by high numbers of thunderstorms. Nevertheless, night-time openings should be reliable from sunset to sunrise. Local daytime openings will be possible on the whole. Night-time skip distances are likely to be between 500 and 2,300 miles.

20m (14MHz) is still likely to be the best DX band between sunrise and sunset, although the band will be noisier than the winter period and not as reliable for long-haul contacts. The higher MUFs at night mean that 20m may remain open during the evening to DX. Short skip may also be possible due to summer sporadic-E.

17m/15m (18MHz/21MHz) should provide a fair number of DX openings during daylight hours, especially to the southern hemisphere. Once again, 15m may struggle to open at times. Both bands are likely to close after sunset. Sporadic-E will provide good short-skip openings, predominantly in the May-June period.

12m/10m (24MHz/28MHz) are likely to be disappointing bands apart from Sporadic-E openings that will provide regular openings out to around 1,300 miles. Multi-hop sporadic-E openings are possible, providing relatively good, but short-lived paths to DX beyond this range. A typical multi-hop opening might provide brief contacts with the Middle East or USA, although they would be very hard to predict.

You can find HF short-path propagation prediction charts from the UK at:

http://www.infotechcomms.co.uk/propcharts/

You can also listen to Steve G0KYA's HF propagation podcast on iTunes or at http://www.g0kya.blogspot.com/

Steve G0KYA

RSGB Propagation Studies Committee

HF Propagation, June 2010

Solar conditions continue to be fairly rotten. In May we had a solar flux low of 69 and a high of …. wait for it …. 83. Hardly what we would expect for the rising part of the new cycle. It really needs to get over 100 if we are to see the higher bands open up to good F2 layer DX. Even then, we are going to have to wait until the Autumn.

But the good news is that the Sporadic E season is opening up the bands nicely, albeit for relatively short skip distances.

Look for very strong signals on 10m and 6m, which will suffer from heavy QSB. As the Es clouds move the countries you are able to work will change.

Peak times for Es are mid morning and mid to late afternoon, although look in the evening too.

Otherwise, Daytime MUFs are likely to be lower than those of winter. Night-time MUFs may be higher in summer than those in winter. Note that DX on the low bands, if possible, is unlikely to occur until around midnight or the early hours due to the late sunset.

But for now, let's look at each band and what you can expect.

On 160m (1.8MHz or Top Band), high levels of static and solar absorption mean that the band will not really support sky-wave contacts during the day. During darkness, short-skip openings may occur, but DX may be a rarity. Occasional openings can occur during the hours of darkness, especially around local midnight/early hours.

80m (3.5MHz) will generally follow the characteristics of Top Band with high levels of static, but will also provide good openings out to around 250 miles during the day. Absorption will grow to a maximum at midday for inter-G contacts. DX capabilities will be poor to fair during the hours of darkness.

40m (7MHz) will suffer from high static caused by high numbers of thunderstorms. Nevertheless, night-time openings should be reliable from sunset to sunrise. Local daytime openings will be possible on the whole. Night-time skip distances are likely to be between 500 and 2,300 miles.

20m (14MHz) is still likely to be the best DX band between sunrise and sunset, although the band will be noisier than the winter period and not as reliable for long-haul contacts. The higher MUFs at night mean that 20m may remain open during the evening to DX. Short skip may also be possible due to summer sporadic-E.

17m/15m (18MHz/21MHz) should provide a fair number of DX openings during daylight hours, especially to the southern hemisphere. Once again, 15m may struggle to open at times. Both bands are likely to close after sunset. Sporadic-E will provide good short-skip openings, predominantly in the May-June period.

12m/10m (24MHz/28MHz) are likely to be disappointing bands apart from Sporadic-E openings that will provide regular openings out to around 1,300 miles. Multi-hop sporadic-E openings are possible, providing relatively good, but short-lived paths to DX beyond this range. A typical multi-hop opening might provide brief contacts with the Middle East or USA, although they would be very hard to predict. Propagation via the F layer is unlikely to occur reliably until Autumn.

You can find HF short-path propagation prediction charts from the UK at:

http://www.infotechcomms.co/uk/propcharts/

You can also listen to Steve G0KYA's monthly HF propagation podcast on iTunes.

Steve G0KYA RSGB Propagation Studies Committee