|2014-2015 Numeralla TV-FM DXpedition Summary|
Geoff Wolfe, Todd Emslie, William Renton
SUB-PAR Es: THE NEW NORMAL?
The 2014-2015 Numeralla DXpedition proved to be the worst so far in terms of Es and tropospheric DX. In SE Australia, both Es and tropospheric DX seem to be on a downward trend. To partially counteract this trend, it took high-end DX equipment, several hours of diligent monitoring, and decades of combined experience to extract the relatively few DX logs summarised in this report. The glory 1980s and 1990s DX decades where strong Es signals could be received even on relative insensitive indoor portable FM radios are gone. These are unprecedented poor DX conditions. Given that the recent Dec 26, 2014 to Jan 4, 2015 Numeralla DXpedition sporadic E (Es) DX logs were well below average in quantity, the initial handwritten notes were limited to both sides of a single A4 size page. Geoff estimates that the current southern hemisphere Es season is the weakest experienced since the Dec 1987 to Jan 1988 season. The decline of low VHF TV and 6 metre beacon indicators only served to compound an abysmal Es season. The net result was extensive periods of dead air time. The lack of signals meant that it was necessary to shift bias to social opportunities and rural sightseeing.
F2 and TEP DX was an improvement over last year's DXpedition, with the highlights being 40.67 MHz Utah, USA Snotel radar via 3F2, 49.75 MHz Chinese TV carriers, and Japanese 6 metre hams. Low VHF DX was confined to Asian fishing boats, Chinese meteor radars, 40.68 MHz (nominal) Australian hospital pagers, and the 40.43 MHz Esso Gippsland data TX. A quick sweep of 30-50 MHz was occasionally checked using the R8500 in 5 KHz tuning steps.
RECEIVING SYSTEM OVERVIEW
A Peter Korner design 15.11 long-boom FM Yagi is mounted horizontally at roughly 18 ft above ground. The 15.11 is hand rotatable. Another wideband fringe VHF horizontal polarised Hills DL4 12-el Yagi covering 45-220 MHz is mounted on a separate mast.
The Korner 15.11 87-108 MHz Yagi is connected to a low noise (0.4 dB NF) pHEMT design indoor RF FM preamp manufactured by AllSat Communications Germany. The RF amp noise performance is sufficiently low enough to hear daily aircraft scatter FM out to ~ 450 miles / 724 km. Sydney FM 150 kW FM @ 190 miles / 306 km via everyday troposcatter averages about 2-3 bars on the main 15.11 + preamp + XDR setup.
For the current DXpedition, the Icom R8500 wideband receiver is used with a Jim Dietrich design UA-701 GaAsFET 2dB NF preamp. The output of the UA-701 is split via a Tratec ES-02 diecast splitter feeding the HS D100 TV tuner and Icom R8500. RG6 Quad 75-ohm coax is used for all cable runs.
Geoff resides on a ~ 100 acre property which includes a homestead where we stayed. The site is located approximately 200 miles southwest of Sydney. The receiving equipment is located in a small house separate from the homestead. The site elevation above sea level is 800 metres (2624 ft). An 800 metre elevation site directly facing the Pacific Ocean would provide a negative horizon. However, there are distant mountains in certain directions when beaming from Numeralla, which compromise low angle DX arriving over the horizon. New Zealand Es and tropospheric signals are diffracted off Mt Numeralla. West bearing is the most obstructed takeoff, while New Caledonia is best. Local horizon blockage variations are not relevant in practice when Es is so poor.
Es SPACE-TIME DISTRIBUTION
A trend in recent years is that Es seasons in SE Australia are progressively starting later and ending early. This was especially true during the recent DXpedition. We discussed some possible factors for the declining Es trend, but whatever the factors, assuming the present declining Es trend continues, broadcast band VHF DX may no longer be worth seriously pursuing at this location.
In addition to monitoring the VK Logger Internet pages, including various pre-sets on the Icom R8500, we also made use of the IPS ionograms, specifically Sydney, Brisbane, Norfolk, and Niue.
The extensive periods of dead air time afforded more opportunity to check the IPS ionograms. Most of the higher value readings (> 10 MHz foEs) were indicated on the Canberra and Sydney ionograms. By contrast, the lower readings (< 5 MHz) were indicated on the Darwin, Norfolk, and Townsville ionograms. This indicates that Es distribution and intensity drops off, at least over certain areas, towards the equator. It also partly explains why low latitude locations such as Darwin are so relatively infrequently received into SE Australia. Higher mid latitude Es seems to peak around 34 degrees south extending from eastern Australia across the Tasman Sea. Numeralla's close proximity to Canberra and Sydney meant that we could not benefit from these concentrated higher foEs areas. Another mystery is the complete lack of FM from Alice Springs.
During last year's trip, we also checked the Norfolk IPS ionogram archives to see if there was any correlation with Geoff's Tongan 2Es FM around 0130 UTC, Dec 26, 2013. The 100 km trace for that time period was less than 5 MHz, so no correlation. The Norfolk ionogram can only sample a small area of the ionosphere, and hence cannot detect other areas of the Pacific Ocean where two intense Es patches are located to propagate 2Es from Tonga into Numeralla. This underscores why IPS ionogram readings are no substitute for real-time (or unattended) monitoring from home.
Niue ionogram averages low foEs < 4 MHz. This could explain why no one in Australia has ever logged Niue FM, also the lack of Samoa FM into NI New Zealand. There seems to be a gradual reduction in average Es ionisation levels heading towards the equator, roughly north of Rockhampton. Townsville and Darwin FM foEs averages are also below average, being mostly confined to < 5 MHz. The low foEs Darwin IPS ionogram readings suggest a priori that Es reception possibilities from Darwin will be restricted, especially for Asian signals located north of Darwin. Hence caution could be warranted before expending funds on a DXpedition to that area during the peak late December Es season.The Norfolk FM ionogram is not always a reliable precursor for NI New Zealand FM because the sampled area is too localised. In practice, the Norfolk foEs needs to be at least 8 MHz for Norfolk Island band 2 FM into Numeralla.
Highest average foEs was indicated on the Sydney and Brisbane IPS ionograms. This is consistant with mid latitude Es peaking around 25 to 37 degrees south.
2Es openings to Darwin from Numeralla are quite infrequent. Indeed, Darwin 100.9 MHz FM hasn't been received since 1996! There appears to be a small window concentrated around Dec 30-31 during the afternoon period from 1500 to 1900 LT. The 50.31 MHz VK8VF Darwin 6m beacon is usually a necessary precursor for West Papua, or Timor, Indonesian FM.
KORNER 15.11 FM YAGI FORWARD GAIN
Will Renton suggested that Geoff's Korner 15.11 FM Yagi is capable of receiving very low power single-hop Es FM, for example, transmitters radiating 1 watt or less. Geoff is able to log certain low power FM via Es that no one else in Australia has logged. 90.0 MHz Richmond, QLD is one of several stations that no other Australian FM DXer has yet reported. The ~ 3 dB forward gain increase over a standard 8-element FM Yagi (e.g. Matchmaster FM8, or Triax FM8) seems to be sufficient to break through a signal-to-noise threshold level. This may also explain possible cruise ship reception on 90.0 MHz from somewhere in the Pacific in the general area between Norfolk island and New Caledonia during the last 2013-2014 Numeralla DXpedition. The 90.0 MHz signal at times also exhibited choppy destructive / constructive phase fading pattern typically received with mobile objects in forward motion.
No low power < 1 watt FM via Es was logged on the recent DXpedition.
Indoor Receiving System Setup.
Left to right on table: Onkyo T-9090 II, Icom R8500, HS D100 DX TV tuner. Onkyo T-4970 FM tuner, Sony St-Sa5Es FM tuner, Sony XDR-S3HD FM tuner. Toshiba C-531 5" TV. The RDX Labs UA-701 GaAsFET wideband VHF RF preamp mounted in black box near the floor at bottom LHS of photo. The 0.4 dB NF FM LNA is mounted directly behind the Sony XDR-S3HD.
EARLY MORNING DAILY TROPOSPHERIC ENHANCEMENTGeoff checked every day from 0630 onward for signs of enhanced tropo conditions. This year proved to be poor, with unprecedented low levels. Tropo modes peak in the early morning hours of ~ 0500 to 0800 LT. This period corresponds to the well documented sunrise lower atmosphere inversion.
We monitored the VK Logger 6 metre ham Internet pages. In previous superior Es seasons there were 6 metre hams operating in locations such as Tonga (A35RK), and Cebu City, Philippines (DU7) that provided early indications of TV-FM reception. It was a disadvantage that 6 metre hams are no longer operating on Norfolk Island, Tonga, and the Philippines.
We were perplexed at the number of short-range < 400 km WSPR 6 metre reports on the VK Logger. We felt this was taking ordinary reception too far. It is comparable to a TV DXer submitting a report of 400 km daily troposcatter BFO-level reception. Also, when Es actually opened, few seem to use USB voice contacts around the 50.11 call channel. The emphasis was on reporting garden variety (e.g. VK5 to VK4) interstate 6m beacons or WSPR. For these reasons, the VK 6m logger is less relevant to TV-FM DXers compared to years gone by.
POWERLINE RF NOISE
At times the PLN reached such high levels that the only remaining option was to beam the DL4 Yagi directly perpendicular to the radiating noise source. This meant aiming northwest, which fortunately corresponded to the general Asia direction. The noise was generally lower on cooler overcast days. RF phase cancellation is one option providing the noise is emanating from a single source. But it is likely that at certain times of the day, more than one noise source is radiating, including a possible faulty appliance which suddenly switches in.
The Sony XDR-S3HD exhibits relatively poor AM rejection; hence when powerline noise is high, we opted to use the Onkyo Integra T-4970 or T-9090 II.
Hills DL4 45-220 MHz 12-el Yagi, and Korner 15.11 FM Yagi aimed north.
Allsat Germany low noise 0.4 dB NF pHEMT design indoor 86-108 MHz FM RF preamp connected to the Sony XDR-S3HD FM tuner .
VHF DX Loggings: times local UTC + 11:
Friday Dec 26, 2014:
1930: Arrived at Geoff's QTH.
Saturday Dec 27, 2014:
~ 2,000 - 2,200 km Es to New Zealand:
0841: Palmerston Nth FM: 89.0 Concert, 90.6 ZM, 92.2 More, 91.4 Rhema, 93.0, 93.8 R. Live, 94.6.
0930: Te Aroha FM: 91.4 Concert, 98.6 ZH, 94.6 Life, 103.4 NIU Huga Huga FM.
0940: Auckland FM: 89.4 Newstalk, 90.2 The Rock, 91.0 ZM, 91.8 More, 92.6 Concert, 97.4.
1007-1100: 40.67 MHz Utah, USA Snotel via 3F2. ~ 13,196 km / 8,200 miles.1435: 33.2 Darwin, 38.9 China (2tx), 49.75 BFO Chinese TV carriers @ ~ 8,000 km.
1445: 44.0 MHz nFM Vision FM, QLD.
1449: 38.15 MHz nFM JA utility.
1449: 40.665, 40.68 MHz hospital pagers Brisbane / SE QLD.
1450: 43.855 MHz tones (Asian radar?).
1512: 49.7604 MHz raspy single TX (Vladivostok, Russia?).
1520: 50.11, 50.12 MHz JAs via aTEP.
Sunday Dec 28, 2014:
1330: 50.282 Townsville @ 1,885 km.
1634: Chinese sweatshop welding machine RF 'splats' up to ~ 42.5 MHz via afternoon TEP.
1634: 37.425 Chinese nFM utility.
1645: 41.245 MHz Chinese nFM utility.
1657: 37.475 MHz, 38.45 MHz Chinese utilities.
1657: 33.2 MHz Darwin radar via F2.
Monday Dec 29, 2014:
0955: 50.024 MHz ZL2WHO Wharite, NZ.
0955: 50.282 Townsville.
1033: VK5 Es: 40.6798 MHz VK5 area hospital pager, 50.315 VK5RBV, 50.32 Adelaide, 55.0 MHz Adelaide radar @ 980 km.
1151: 40.68 MHz hospital pager.
1420: 49.75 MHz Chinese tx's BFO via aTEP.
Tuesday Dec 30, 2014:
0800: Tested Tecsun PL-390 + Hills DL4 Yagi on Sydney troposcatter and aircraft scatter FM. Respectable results, significant improvement on inbuilt whip antenna; hence adequate setup for mobile DXpedition. However, as expected, signal strength significantly down relative to the Korner 15.11 + German LNA. The PL-390 + whip just sensitive enough to hear 306 km Sydney FM on the inbuilt whip when standing outside.
1007: 50.08 MHz FK8SIX Noumea, New Caledonia via Es @ ~ 1,400 miles / 2,252 km.
1330: 50.281 MHz Atherton @ 1,320 miles / 2,124 km.
1330: 50.282 MHz Townsville.
1429: 91.3 MHz Hot FM Moranbah, 91.7 4ABCRR Dysart, 92.7 4ABCRN Bowen, 95.1 / 96.7 Bowen, 88.0 Tourist Radio Proserpine.
1449: 50.11 VK8AW / portable in central QLD.
1557: 49.75 tx's @ BFO level.
1715: 50.31 VK8VF Darwin via 2Es, but no sign of 33.2 radar.
1735: 50.11 VK8RR Darwin via 2Es @ 2,021 miles / 3,252 km.
1735: 49.75 China chC1 TV carriers @ S3.
Wednesday Dec 31, 2014:
0937: 50.08 Noumea.
0951: 50.282 Townsville.
1146: 50.281 Atherton.
Thursday Jan 01, 2015:
0835: 90.0 MHz The Rock, 91.6 MHz More FM Kaitia.
1359: 89.0 MHz Concert, 90.6 MHz ZM FM Palmerston North, NI NZ.
1404: 88.6 MHz Dunedin.
1411: 89.4, 90.2, 91.0, 91.8, 99.8, 95.8, 92.6, 93.4, 101.4, 103.8, Dunedin.
1420: 89.6, 95.1, 95.9, 96.7, 98.3, 96.6, 97.5, 99.9, 90.3, 93.5 MHz Alexandra.
1423: 94.4, 92.8, 94.2, 92.0, 91.2, 90.4, 96.0, 100.0 MHz Queenstown.
1427: 90.0, 90.8, 89.2, 91.6, 92.4, 93.2, 94.0, 94.8, 95.6, 96.4, 93.2, 98.0, 98.8, 99.6, 101.2, 103.6, 105.2 MHz Invercargill.
1428: 91.3 MHz rural ZL4.
Friday Jan 02, 2015:
0822: 50.282 Townsville.
1615: 50.08 Noumea.
1840: 50.282 Townsville.
2000: 40.43 MHz Esso Gippsland via 240 km Es
2000: 50.057 VK7RAE, 50.297 MHz Hobart, 50.2 MHz VK7DX Launceston.
Saturday Jan 03, 2015:
0804: 50.024 MHz ZL2WHO, 50.04 MHz ZL3.
0810: 89.4, 90.2, 91.0, 91.8, 92.6, 94.2, 95.0, 95.8, 101.4, 100.6, 102.2, 105.4, 99.0, 98.2, 97.4 MHz Auckland.
0910: 40.6662 MHz Hospital pager Adelaide area.
0910: 50.315 MHz Barossa, VK5, 50.32 MHz Adelaide.
1009: 55.0 MHz Adelaide radar.
1116: 90.1, 90.9, 91.7, 96.5 MHz Westport, NZ FM.
1300: 50.282 Townsville.
1408: 49.75 BFO.
1815: 40.68 MHz hospital pager Brisbane area.
1815: Band 2 FM Es to SE QLD, including Bundaberg, Maryborough, Gympie, Nambour. 87.6, 87.8, 88.7, 92.3 MHz KIX Country Pialba, and many others up to 107.5 MHz - Frasier Coast FM.
1815: no sign of 44.0 MHz Vision FM; hence rules out SE QLD and FNQ.
1851: 90.0, 91.6, 92.4 Kaitaia.
1908 - 1921: 89.9, 91.9, 93.9, 95.9, 98.2 MHz average 3-bars strength from Norfolk Island @ 1,200 miles / 1,930 km. Also received on Will's Tecsun PL-390 + whip.
Sunday Jan 04, 2015:
NI New Zealand via Es:
0810: Palmerston North, Te Aroha FM via Es, e.g. 89.0, 90.6, 91.4, 98.6, 101.0, 89.0 MHz, etc.
0825: Auckland FM: 89.2, 97.4, 99.0, 99.8, etc.
0830: 90.0 MHz Concert FM - likely not Invercargill.
Webpage compiled 8-1-2015.