Showing posts with label HF. Show all posts
Showing posts with label HF. Show all posts

Saturday, 7 December 2019

DXing The Utilities (Part 2)

The following blog was originally posted in 2015 but might still be of interest to anyone with a shortwave radio! Since the migration of HF aero traffic to satellite has been slow, there is still a lot of oceanic traffic to be monitored on the bands, 24/7.

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Unlike the growing scarcity of good HF maritime DX targets, there is still a large amount of HF aero activity to enjoy! Even with the move to satellite comms, there is still, at any given time of the day or night, hundreds of aircraft using HF radio to communicate with controllers, companies and home bases. Both commercial aviation and the military, as well as many privately owned aircraft, use the HF communication networks to keep them flying safely. From trans-oceanic 777s' and military transports to single engine float planes in the Canadian Arctic and Alaska, the sky is alive with DXing opportunities!

A huge percentage of commercial aircraft are delegated to moving freight and many of them can be heard on HF radio. Many of the planes in use are retired passenger planes that have been reconfigured for moving cargo. Back when I did this type of listening, older DC-8s seemed to be particularly popular, especially on the nightly South / Central America to Florida routes. I suspect that nowadays, these have been replaced with older DC-10's and 747's.


'FINE AIR 432' was logged on March 24,1996 at 0435Z while working Miami Radio on 6637kHz. The DC8-51F (Freighter) was over Bogota while enroute from Lima to Miami.




'NIPPON CARGO 083', a 747-200F, was logged
on 8891kHz working Baffin Radio. They were reporting position "LT", a waypoint above Alert, at 82-31N / 62-12W, westbound on Polar Track "Quebec".
The freighter was enroute Amsterdam to Anchorage.



The Antonov 124-100 is a gigantic Russian built freighter - capable of transporting in excess of
120 tons. This is aircraft "RA-82045" which was logged as 'HEAVYLIFT 878' in June, 1996.



Operated by Volga-Dnepr, 'HEAVYLIFT 878' was working Dakar (Senegal) Aeradio on 6535kHz reporting FL240 and position 13-14N / 24-26W enroute Cape Verde Islands to Sao Paulo, Brazil.


'AFM 01' was a DC8-55F logged while working Brazzaville Radio (Congo) on 8903kHz. It was at FL350, enroute Harare, Zimbabwe to Kano, Nigeria at the "MPK" waypoint, 250 miles east of Kinshasha, Zaire. Brazzavile was advising of 'crossing traffic, same level...please say intentions'... Yikes!

On another evening I heard the Dakar (Senegal) controller advise a British Speedbird 747 to 'go to flight level 330 ... please go now ... go very very fast'.


'AFM01' (Affretair) was Z-WMJ, shown here on final approach to Gatwick.



'PACIFIC AIR EXPRESS 3517' was heard on 8867kHz working Brisbane Radio while over the Coral Sea. The Lockheed L-188C four-engine turbo prop was enroute Honiara to Brisbane with a load of fresh tuna destined for the Japanese market. N360Q, shown on the ground at Honiara, was leased from the states and operated by Charrak Air.



The U.S. military is still active on HF radio and some interesting catches can be had. During the testing phase of the 'cruise' missile, the missile navigation systems were tested over the Northern Territories and Alberta. Once dropped from their B-52 launch platforms, the missiles were tracked across Alberta by Advanced Range Instrumentation Aircraft (ARIA). 'AGAR 93' was heard on one such mission on 11176kHz. 'AGAR 93' was # 81-0893, an EC-18 (modified Boeing 707) out of Wright Patterson' 4950th Test Wing. According to the aircraft commander who signed my verification, the aircraft was approximately 1 hour S.E. of Namao, Alberta. One can easily see why # 81-0893, shown here, was affectionately known as "The Beast".


'DOOM 81' was a gigantic B-52H from the 96th Bomb Squadron, stationed at Barksdale AFB, LA. The appropriately named big bomber was heard on 11176kHz while working Ascension Radio and was just about to rendezvous with their mid-air refueler when the mission was aborted. This was the first and only B-52 that I was ever able to confirm.

 

'ROMA 99' was logged on 17975kHz while working Thule Radio. They were taxiing for takeoff at Dulles International in Washington D.C. and reporting a minor fuel-pump problem. 'ROMA 99' was a KC-135R Stratotanker, # 62-003512, from the 509th Air Refueling Squadron at Griffis AFB, NY.



'REACH 71839' was heard on 11176kHz while working Albrook AFB, Alaska. Tail # 65-0239, this 'REACH' flight was an aging C-141B Starlifter, at one point, the Air Force's major transporter. 'REACH 71839', out of McChord AFB, was enroute Brazil to Puerto Rico.



There's still plenty to be heard on HF, outside of the amateur bands and a quick internet search on 'Utility DX' will turn up several interesting and informative sites ... each one having an abundance of related links to follow. Here are some that will be helpful:

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A freshly updated list of all active HF aero frequencies. Also check their list of active aero 'callsigns'

http://monitor-post.blogspot.ca/p/this-international-hf-aero-frequency.html

If you can catch an aircraft's four-letter SELCAL code, often given during waypoint checks, you can search here for more info on the actual aircraft itself:

http://www.airframes.org/reg/b18305 

The Milcom Blogspot:

http://mt-milcom.blogspot.ca/

Thursday, 29 December 2016

CQ - 630m Crossband Anyone?





A very beautiful QSL arrived in the mail last week, confirming my 630m crossband contact with Harry, WØLS, in Minnesota.



According to Harry's card, this was the first time he had ever listened on 630m and was very surprised to hear me, let alone complete the two-way contact.



Harry was transmitting on 80m CW while I was transmitting on 630m, on 473.00 kHz. It really does not take too much to be able to hear signals on 630m, especially if you are not overwhelmed with a high noise floor ... most low band wire antennas will hear pretty well down there, when pressed into service.

This week, the card from Jeffrey, KGØVL in Iowa arrived. This one also confirmed a 630m crossband contact. Both of these QSO's were made during the November's 630m activity night.


Jeffrey was transmitting on 160m while listening to my signal on 473.00 kHz with his 160m inverted-L.

It's not really necessary to wait for another activity night to have some fun, so ... if you would be interested in trying a crossband CW contact, I would be more than excited to give it a shot.

I can listen on 160, 80 or 40m for you, if you can listen on 630m for me! If we can arrange a sked, I could probably talk a few of the other local 630m VE7's into tagging-along so that you end up with a double or triple-header of VE7's in the logbook.

Please e-mail if you would like to try... ve7sl at shaw.ca

Wednesday, 10 August 2016

Remembering The 'Woodpecker'



Early last week, Paul (K7CW) sent me a link to an interesting video showing the Duga antenna system. The term was not familiar to me but when I went to the site I immediately recalled the significance of what I was seeing!



Those of you that have been hams for a long time will no doubt recall the Russian 'Woodpecker'. The 'Woodpecker' was a strong, fast repeating signal / racket that often wiped out amateur communications on 20m here in North America ... maybe other parts of the world as well.

Amateurs with yagis eventually determined that the signals (yes there was more than one it seemed) were coming from the USSR. The QRM was persistent and in spite of formal complaints being lodged via diplomatic channels, continued for many years ... from 1978- 1989. Some of the new transceivers built during the time actually had a 'WOODPECKER' position on the noise blanker switch, hopefully offering some relief to the problem.

For you younger folks, here's what Duga usually sounded like:


Several web searches brought up numerous descriptions of the Duga (Russian for 'arc' or 'bow') project, some with conflicting information. From what I can sort out, there were three Duga sites ... one near Chernobyl, another near Chernihiv and a third, much later, in Siberia. The first two (Duga and Duga-1) were in the Soviet Ukrainian SSR (now Ukraine) while the third was located near Komsolmosk-on-Amur in the Russian far east. One source indicates that the second Chernobyl site is often misidentified as the Duga-3 array and should be referred to as Duga-1, with Duga-2 being the Siberian location.

Initial speculation suggested this intrusive signal was some form of 'jammer' ... very common during the Cold War. It wasn't long before the true nature of Duga was thought more likely to be an 'over-the-horizon' (OTH) long-range radar system for detecting the launch of North American missiles aimed at the USSR. The three radar sites gave the Soviets good over-the-pole coverage as well as to the east, where it could also be utilized for tracking domestic rocket launches.

courtesy: http://www.globalsecurity.org/wmd/world/russia/steel-yard.htm

The antennas themselves appear to be phased dipole curtain arrays, commonly used in various configurations by shortwave HF broadcasters.

courtesy: http://www.antenna.be/hr.html
These antennas featured an array of phased dipoles in front of a screen curtain 'reflector', often made of rows of wide-spaced wires. One source indicates that the Duga arrays developed ~30db gain over a standard half-wave dipole ... an enormous task on these HF frequencies. One system had a '4/4/1' configuration meaning each bay consisted of a dipole array 4 wide and 4 high. Another source spoke of  a system that was 32 high and 16 wide in total. Whatever the numbers, these free-standing structures were gigantic and true marvels of engineering. The large Chernobyl array is 150m high and 500m wide, with an estimated weight of ~ 14,000 tons.

Each site was paired with a receiving array ... remember, this was a radar system, with two of the three systems having the receiving array located tens of kilometers from the transmitter. The Chernobyl Duga is said to have had the receiving antenna located on site. Sources discussing physical size indicate the dimensions for the receiving array to be larger than those of the transmitting antenna. It seems possible then, that the pictures and videos commonly found are those of the receiving array and not of the transmitting antenna. It might make sense to have more gain on 'receive' than on 'transmit' as echoes from small targets many thousands of miles away would not be easy to detect. No matter what the actual case, I can only imagine the fun of hooking up an HF transceiver to one of these arrays during a DX contest on 20m CW!

The Chernobyl site shows two arrays, side-by-side ... possibly the larger being that used for receiving and the smaller one for transmitting. This antenna has been noted as a 30/10/2 array ... 2 bays, 30 dipoles wide and 10 high, 600 elements in all!

Further research tends to indicate that each dipole is what is called a 'Nadanenko' dipole. The main feature of this style was its cage-styled construction, giving the element a large diameter resulting in a broad bandwidth.

courtesy: https://shema.info/en/antenna/
Each dipole was fed at the center with open-wire ladder line and some pictures show obvious signs of open wire phasing lines, no doubt used to electrically steer the array over its reported 30 degree directional pattern.

courtesy: englishrussia.com
After watching the video, Paul (K7CW) made some interesting observations, some of which may be seen in the above photograph. His eyes must also be a lot better than mine as he managed to correctly count the number of dipoles in the array!

First, you see that there are two sets of arrays 15 driven elements wide by 10 driven elements high for a total of 600 elements! They are intermeshed and offset from each other by 1/2 wavelength both vertically and horizontally. There is a horizontal wire screen reflector behind the driven elements.

Some of the other things I noticed are ...

... you can see the open-wire feeds and reflector screen. Each set of collinear elements is fed individually with open wire line. There is a support line between each two bays of driven elements.

... that the reflector screen is supported on the sides by the stand-alone free-standing towers at each side of the array. (I had been wondering why they would have those towers next to the array like that. Now I know.)

... that the element supports are steel pipe instead of fiberglass (or something similar). Apparently, the shape of the radiators allows for the pipe supports to enter the element cages at the element low-impedance point which made the supports invisible to the antenna and also allowed for the supports to not radiate themselves.

courtesy: http://anzee.livejournal.com/65530.html
There are a number of YouTube videos showing various adventure-seekers climbing the Duga array near Chernobyl. The videos give you a better idea of its sheer mass as well as a closer look at the dipole structures themselves.



The Duga system was operative between 7 and 19MHz, with 40kHz wide pulses, usually lasting for about seven minutes. The most common pulse rate was at ~10Hz but this sometimes varied. Power levels used often mention 10 megawatts but it's not clear if this was RF output, peak pulse power or ERP.

It's somewhat gratifying after all these years, to actually see close-up, where the Woodpecker signal started its journey around the world and to appreciate the superb engineering that went into these impressive structures ... but sad to see the last one in such a rusted state of decay and abandonment. It would be nice to hear it just one more time ... but please, only for a couple of minutes.

Friday, 1 April 2016

The Joys Of HF

It seems that contesting clubs in Manitoba and New England want to show non-hams, new hams and all hams, the 'joys of HF radio'. In a beta test of their idea, called 'Discover the HF Experience', participants in Manitoba will have the opportunity to get on HF by operating K1K, in Massachusetts, remotely, from the Garden City Canada Inn located in Winnipeg, Manitoba, on Saturday, April 2nd.

Future events will take place in Massachusetts from the Yankee Clipper Contest Club's venue on April 10th and a much larger operation, featuring four operating positions at Dayton in May, at the ARRL's Expo site. Full details of all operations can be found here.

The idea was the brainchild of Gerry Hull, W1VE who, along with Cary Rubenfeld, VE4EA, has brought his idea to life.

“Our amateur population is at an all-time high, but most new hams are getting a Technician ticket, getting on VHF and UHF, and hanging out with like-minded friends,” Hull said. The limitations on what Technician licensees can do often leads to boredom, Hull said, “and they drop out of the hobby. They never get the exposure to HF ham radio, and as any veteran radio amateur can tell you, that’s a lifelong exploration.”

Now I fully concur that far too many of our newest amateurs land on VHF or UHF and never move, almost totally unaware of what HF radio is all about. Being exposed to HF radio is a great idea, yet ... and maybe I'm just old-fashioned, but I'm not sure that this 'first experience' is best done via remote operation. From my own initial exposure to ham radio, seeing the magic happen in a basement or attic radio shack, complete with glowing dials and a wall full of QSL's from all over the world, was enough to hook me for life. I'm pretty sure that same feeling can't be conveyed by sitting in front of a laptop and pushing a few keys.

I am not a fan of 'remotes' but from what I have seen, this may be one of the better examples and if it grabs and convinces even a few to explore HF on their own, that would be a good thing ... then all we'd have to do is get them on CW !