# Antenna identification



## sidnik77 (Mar 24, 2017)

I believe this is the best place to ask what antenna is this?


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## P.Arnold (Apr 11, 2013)

A Direction Finder loop aerial (DF) (Ballini Tose) mainly for use on MF band.
Probably got spelling wrong.


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## sidnik77 (Mar 24, 2017)

Thanks alot Arnold


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## P.Arnold (Apr 11, 2013)

Spelling should be Bellini Tosi.

There would have been another aerial, either wire or whip associated with the loop, called a “sense” aerial.


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## King Ratt (Aug 23, 2005)

Bellini-Tosi fixed DF loop. Often feeding Marconi Lodestone or Lodestar equipment.


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## Varley (Oct 1, 2006)

Almost certainly Marconi - a patent issue I was told. I am not sure when that ran out but the SAIT outfit on Conoco Europe in 1977 was fixed loop too (triangular? attempting to minimise skywave reception?).


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## John Leary (Mar 30, 2005)

Sidnik77

On one ship I sailed on in the 1960’s, two of the four cables connecting the Bellini Tosi loops to the DF receiver developed a leakage between the copper inner core and the lead outer sheathing causing concerns about the impact of the leakage on the accuracy of the DF. The remedy was to replace the cables. The water around the loops in this photograph suggests that the magnitude of the dampness in the cables is of an entirely different order! On some ship installation the sense antenna for the DF was a short wire antenna but in this photograph I believe the sense aerial is the short vertical rod inside the loops.

Best Regards
John


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## Ron Stringer (Mar 15, 2005)

John Leary said:


> On some ship installation the sense antenna for the DF was a short wire antenna but in this photograph I believe the sense aerial is the short vertical rod inside the loops.


Not true John. The rod to which you are referring is a mechanical support, part of the arrangements for holding the two loops together and securing them to the base. The DF sense antenna was always separate with this Bellini-Tosi antenna version. Later versions could be fitted with a fibre-glass reinforced whip sense antenna, screwed into the top of the junction of the two loops (although the loops were triangular, rather than circular as in this version).


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## Ron Stringer (Mar 15, 2005)

Varley said:


> Almost certainly Marconi - a patent issue I was told. I am not sure when that ran out but the SAIT outfit on Conoco Europe in 1977 was fixed loop too (triangular? attempting to minimise skywave reception?).


David,

With the "Lodestone 3" DF, MIMCo introduced a B-T loop which was formed of two triangular aluminium loops. Sadly I can't lay hands on a photo but each loop was formed from T-section aluminium bar, 8cm or 9cm wide, bent to form an isosceles triangle. The two loops were set at right angles with a vertical support rod from apex to base. At the apex it was possible to attach a vertical whip antenna to act as sense antenna (a separate sense antenna arrangement - wire or vertical whip - was optional).

By that time DF was coming to the end of its maritime usefulness - so you didn't see many of them around. These triangular antennas were sold to other RAMAC companies (SAIT, Debeg, Radio-Holland etc) but I don't know in what quantities.


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## Varley (Oct 1, 2006)

Thanks Ron. I only sailed with the Tobleronic design on the SAIT ship (also the only non-British ship that I signed on). David V


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## MikeK (Jul 3, 2007)

John Leary said:


> Sidnik77
> 
> On one ship I sailed on in the 1960’s, two of the four cables connecting the Bellini Tosi loops to the DF receiver developed a leakage between the copper inner core and the lead outer sheathing causing concerns about the impact of the leakage on the accuracy of the DF. The remedy was to replace the cables. The water around the loops in this photograph suggests that the magnitude of the dampness in the cables is of an entirely different order! On some ship installation the sense antenna for the DF was a short wire antenna but in this photograph I believe the sense aerial is the short vertical rod inside the loops.
> 
> ...



Boom Boom ! very good John. I could say very dry indeed no pun intended. I wonder why they hung the frogman ?

Mike


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## david.hopcroft (Jun 29, 2005)

This one was an AEI Fixed BT loop. I guess one of the wires - not the mast stays - would be the sense aerial. 

I did actually use it in anger once. We stopped mid-Indian Ocean to transfer a cylinder of fridge gas to one of Ludwigs tankers that had a leak. We were about a day behind him and so DF'd him on approach and so came up on the nose.

David
+


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## P.Arnold (Apr 11, 2013)

On Maggie Booths we sometimes had to enter the Amazon north channel of Marahon. All surrounding areas was beach and vegetation.
Not good radar definition. We used DF.

On another occasion ( Delphic, Shaw Savill) we rendezvous with the “Talisman” , we had a Doctor on board, she had a crew member with an injury. We were heading towards each other mid Pacific. DF used well before v/l appeared on radar.


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## Tony Selman (Mar 8, 2006)

When I was a Brocklebank Line R/O manning the Cunard cargo ships it was a regular occurrence that you would cross the Atlantic totally on DR's never having seen the sun or stars all trip. Common to be called to get D/F's as you approached land at either end to give the navigators some idea where we were. On one particular trip a very arrogant navigator, whom I did not get on very well with, severely questioned my near perfect cocked hat of three bearings in front of the Captain when we were approaching the south of Ireland. Privately I was a bit suspicious that the bearings appeared to be so good as the 2/O had us about 40 miles away. When we got a radar bearing on the South of Ireland I was almost spot on and the Captain privately thanked me. Oddly enough the 2/O did not say anything.


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## Varley (Oct 1, 2006)

On Tilapa (1972) we used DF when approaching the entrance to the Mississippi's South West Pass otherwise it was only check bearings. On some helicopter calls off Capetown we were asked to transmit so that we could be DF'd.


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## mikeharrison (Aug 8, 2008)

Used DF on BP Tankers when approaching Ports on the low-lying West African coast (too low to pick up on Radar until too close), but there were some nice high power Aero radio beacons there to use .

When working for BP North Sea, we had a Radio Beacon on one of the Forties platforms and a DF receiver fitted to the high speed rescue boat (with a left/right indicator) so that we could find our way back in poor visibility.

Regards, Mike


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## david.hopcroft (Jun 29, 2005)

I also used one of these once when coasting Hull-Liverpool light ship north about, somewhere off the Dornoch Firth. 'Twas a dark and stormy night' quite literally and produced quite good cocked hats every hour for most of the night. It is not easy keeping the loop steady in a gale. The 2/0 was appreciative, but the Capt was somewhat non-commital.

David
+


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## spacetracker (Jun 17, 2008)

Had pretty much the same set-up on Clan Maclaren/GSSC (?). Played around with it while coasting in Europe and used it with vengeance making landfall approaching South Africa at a panicky 2/0's request. Was eventually confirmed as spot on when they worked out where we actually were.


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## Riccarton (Mar 23, 2009)

Going between Land's End and South Wales in May in fog, provided bearings for several cocked hats. When the radar did pick up land the Master comment favourably on the accuracy of DF generated positions.


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## IvortheEngine (Sep 2, 2016)

*Finding a Doctor using DF*

In 1974 I joined Ellerman City Liners m.v. "City of Worcester" for the first of three voyages I did on her. We sailed from Birkenhead bound for Nacala, Mozambique and another seven discharge and load ports up the East African Coast and the Red Sea. We had passed the bulge of West Africa and were in the Bight of Africa around half way between Freetown and the Cape of Good Hope when, in the middle of the night, I was summoned from my pit by the Old Man and the Purser who informed me that "Wee Jim" , a first trip Junior Engineer had had an accident and had a nasty gash on one of his toes. They had patched him up as best they could but he really needed the services of a doctor and could I try to see if any ships in the vicinity had one? I duly tried QSQ (Quick Send Quack) on 500 Khz but no takers. I did hear one response from a Russian fishing factory trawler hundreds of miles to the North but nothing nearer and the static was fierce. After a while the Old Man told me to pack it in and try again in the morning. My next attempt was more fruitful and we were answered by the Italian Lloyd Triestino Liner "Europa" which was a few hours South of us Northbound from Capetown to Italy. We took DF bearings of each other for some time ( long dashes in turn on 410Khz) as our courses converged until we appeared as blips on each other's Radar. We eventally met and, in the Mid South Atlantic swell, " Europa" put down a lifeboat and brought a Doctor and a couple of nurses across (I've never seen so many pairs of binoculars appear on the bridge as when someone said there were nurses coming)....They patched "Wee Jim" up and gave the Purser some appropriate Sulfa drugs to prevent infection and even offered to take Jim to Trieste with them ( Jim declined their kind offer as this was his first trip to sea and he hadn't even reached his first foreign port of call yet!). It all ended well...Jim survived and must have enjoyed the rest of his first trip because he signed on for a second a couple of months later. This thread provides an opportunity to thank the Officers, Crew and Medical Staff from "Europa" for their professionalism and kindness that day. ( The Officers and Crew of "City of Worcester" did a great job too as did the old Marconi "Lodestone" D/F).


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## aussiesparks (Nov 11, 2009)

Was on the Colorado Star (no radar fitted) approaching the channel in light fog, was asked to do DF bearings and supplied same, about an hour later had same request and this put us over 20 miles further on (normal speed about 16 kts) this was rubbished until shortly later the mates picked up land and we were exactly as I had told them. "DF is only good if it agrees with what they are thinking"


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## gordonarfur (May 27, 2018)

I sailed with the USS of NZ (unfortunately) in the early sixties , no radar, no echo sounder, DF with a fore and aft aerial , decks and rigging festooned with aerials put up by the crew, no calibration chart. The old man requested a DF bearing just as the sun was setting and the beacon was at an angle which may have caused the beam to deviate slightly as well. Told him so, he did,nt listen , took the bearing worse than useless finished with open warfare between us.


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## spaarks (May 1, 2009)

At Hardcastle Street we had AEI gear, including a single rotatable DF loop.
The Bellini Tosi (Marcomi patented) system was quite clever. The 90 degree loops were replicated in the DF receiver and had a single rotatable loop inside it. If I remember right the Lodestone had a manual direction dial (goniometer?) and the Lodestar had an automatic servo driven gonio.
The loop(s) had a figure-of-eight reception pattern, ie with two nulls at 180 degrees. The sense aerial was used temporarily to resolve the ambiguity.
I liked DF but rarely had to use it in anger, except for 'check bearings'.

The reception pattern was greatly affected by the ship's metalwork and had to be calibrated to provide a Quadrantal Error chart (in a similar to the Compass Deviation chart).

You had to have 3 (or was it 5?) check bearings in each quadrant in a year to satisfy the yearly Radio Survey. Checks could be done when passing a DF station.
If not it had to be re-calibrated. This was usually done by a boat with a DF transmitter circling round the ship. I think the R/O was allowed to do it yourself, with the ship's lifeboat and lifeboat transmitter, or by having the ship slowly turn on the spot within visual sight of a DF station.


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## Ron Stringer (Mar 15, 2005)

spaarks said:


> I think the R/O was allowed to do it yourself, with the ship's lifeboat and lifeboat transmitter, or by having the ship slowly turn on the spot within visual sight of a DF station.


The ship didn't have to rotate "on the spot", it was sufficient to steam around slowly in a circle, whilst the visual observer and the DF equipment operator took and recorded simultaneous bearings at intervals. The two sets of recorded bearings were then compared and the differences plotted on a chart (the DF Calibration Chart) showing the resultant error at each bearing relative to the ship's bow. 

Using the chart, future radio bearings could be corrected to compensate for the errors inherent in the ship's electro-magnetic profile.

In the UK, most major ports had a DF calibration beacon located at a convenient lighthouse in the vicinity. In the Northeast it was Souter Point Lighthouse, roughly midway between the Tyne and the Wear. On the Clyde it was Cloch Point Lighthouse. The radio beacon would be made available on demand, so that ships leaving the river, either as new-builds or following significant changes to the ship's superstructure and rigging, could calibrate the direction finding equipment. 

Carrying out calibrations on ships that were trying to get away to sea before the weekend was a nice overtime earner and a cushy job for Friday afternoons when I worked in South Shields. Only down side was getting off into the pilot boat in bad weather from large ships that, being unladen, had substantial free-board. A young man's game.


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## spaarks (May 1, 2009)

Ron Stringer said:


> The ship didn't have to rotate "on the spot", it was sufficient to steam around slowly in a circle.
> 
> Yes, that's right, of course.


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## david.hopcroft (Jun 29, 2005)

Ref my post at #17 , the 'advantage' of the rotating loop was that you knew the ships head and so where you should be looking. Sensing was not a problem. 

Check bearings were difficult, especially with a very large 'lump' of metal as in my #12 . The lighthouses on the South African coast were favourite especially northbound when the prevailing currents meant the best track was close to the coast. The only check I did involving rotating the ship (not the one in #12 but the same AEI version of the BT Fixed loop)) was at St Francis light at Durban. We logged arrival time, then dropped back to check the DF. 

David
+


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## gordonarfur (May 27, 2018)

Unfortunately, leaving Liverpool for Auckland we needed to calibrate the DF. asked the old man to slowly rotate the ship when the pilot had left, moans and groans from the bridge as if a half hour delay was going to affect our eta in Auckland. idiot mates !!!


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## R651400 (Jun 18, 2005)

Sailed with both Bellini Tosi and rotating loop DF aerials.
The latter with a Greek 2nd mate never confident with his sextant asked me when well off the Brazilian coast to confirm his noon sighting with a DF bearing. I think there were days when my bearing went down on the chart instead of his noon calculatioons.
|nother Greek (American) captain insisted when leaving port day or night all the navigational aids Radar Loran and DF were to be switched on and ready for use.
I complied with his request but insisted though the Lodestone DF was switched on "night effect" error meant categorically no DF bearings outside daylight hours on my part.
Regarding long range navigational accuracy before Inmarsat? Doubt there was anything that could outclass Loran.


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## spaarks (May 1, 2009)

R651400 said:


> Regarding long range navigational accuracy before Inmarsat? Doubt there was anything that could outclass Loran.


I agree.
Loran A wasn't very accurate as it relied on pulse (envelope) matching and was on MF - with major skywave problems. But Loran C was great - it was on LF (100kHz I think) and was cycle matching.
We needed the accuracy for cable work.

There was also OMEGA which had a longer range, on VLF, but wasn't accurate enough for us.

The Decca DL21 was a superb piece of engineering. Me and John Otley did a three-week course on it at the Decca training school (in the west country I think) in the '70s.

You set it up to manually lock on to the 3rd cycle of each transmitter, using a built-in scope. and then it automatically tracked the third cycle - hopefully. The main problem was QRN at night especially in the tropics. Of course, as the 'expert' I was often called out to reset the matching.

Later fully automatic units were developed and took all the fun out of it.

The 'fun' came back with the Magnavox Satnav (Transit) with its big helical aerial and HP2100 computer. The 'fun' came in programming it. You had to manually enter the bootstrap loader via the front panel keyboard, in Octal. 017700 is burnt into my brain! Then you loaded the program on punched paper tape using the ASR33 tape reader. Took about 45 minutes - if it didn't jam!

Mobile phones aren't half as much fun!


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## Varley (Oct 1, 2006)

I remember that on Conoco Europe. Not sure about the model number but ours was cassette tape loaded. Never managed to get it to work. I think our mini was Honeywell but that also is time misted.


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## P.Arnold (Apr 11, 2013)

gordonarfur said:


> Unfortunately, leaving Liverpool for Auckland we needed to calibrate the DF. asked the old man to slowly rotate the ship when the pilot had left, moans and groans from the bridge as if a half hour delay was going to affect our eta in Auckland. idiot mates !!!


As. Marconi tech (Liverpool) we often had to sail with a ship from Liverpool to Point Lynas, Anglesey to do a calibration. We would establish at the beginning who was in ‘control’. I used to establish a DF gong every 10’ on the DF with the nav’ using voice pipe to signal the visual, as the ship did a circle off P. Lynas. Would draw up the QE curve, sometimes with a note as to the deck cargo.
We would leave the ship with the pilot and the ‘docking bottle’ and spend a night at the Pilot’s “hotel” on Anglesey, then hitch a lift back to Liverpool with one of the pilots.
It wasn’t always that easy when asking the old man to do a second turn, the ship’s rate of turn seemed to be 10 times faster than the first,...... but fun.


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## BOB87 (Aug 31, 2019)

Hi Denis,.. I too was at Hardcastle Street:.. a Lifetime ago,..I remember the DF, the Hermes and other stuff;( was the smaller radar a KH? ) but the Q29 was burned in my brain,...remembering the 4 Stages and of course reproducing the full schematic circuit:.. Anyway,..on an Ore carrier, I tried, (with the Old Mans previous permission) to do a DF calibration prior to us leaving Birkenhead,..(or was it M'boro?), ore terminals are very similar, lol: :.. Bottom line:.. With the 3rd Officer uptop doing the visuals, and Me in the Wireless Room, (Big Sign on the ever open door),...taking synchronised readings,.. we never got past 180 degrees,.. each time we swung,.. we had to stop and get outta someones elses way. Three times we tried,.. He then gave up,.. and said " Make do with what you have Sparks ,we're getting underway " .....bit, but, but... "No Buts"...and that was that,...I've often thought that if Sparks were to contribute some of their own experiences, and put them all in a book,... it would be an absolute Treasure of "Life in the Radio Room,.. Warts and All ",...lol


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## Wismajorvik (Dec 29, 2011)

Not DF but I was on a Magnavox satnav course, (possibly at Muirheads). Never saw one again. Played with a Canadian Marconi Company satnav but never on a vessel. Worked with SHORAN and Alpine positioning systems. Only time I tried to use Loran was approaching the Virgin Islands, no joy. Once docked discovered the settings as indicated in the ALRS were incorrect.


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## spaarks (May 1, 2009)

BOB87 said:


> Hi Denis,.. I too was at Hardcastle Street:.. a Lifetime ago,..I remember the DF, the Hermes and other stuff;( was the smaller radar a KH? ) but the Q29 was burned in my brain,...remembering the 4 Stages and of course reproducing the full schematic circuit:.. Anyway,..on an Ore carrier, I tried, (with the Old Mans previous permission) to do a DF calibration prior to us leaving Birkenhead,..(or was it M'boro?), ore terminals are very similar, lol: :.. Bottom line:.. With the 3rd Officer uptop doing the visuals, and Me in the Wireless Room, (Big Sign on the ever open door),...taking synchronised readings,.. we never got past 180 degrees,.. each time we swung,.. we had to stop and get outta someones elses way. Three times we tried,.. He then gave up,.. and said " Make do with what you have Sparks ,we're getting underway " .....bit, but, but... "No Buts"...and that was that,...I've often thought that if Sparks were to contribute some of their own experiences, and put them all in a book,... it would be an absolute Treasure of "Life in the Radio Room,.. Warts and All ",...lol


Hi Bob. You must have been in a later class than me - I got my tickets in 64. At that time there was no Hermes, just a K-H as you say. The examiner put a superconducting valve in it which stumped everybody - but he talked us through it. I guess it was a good way to determine if we knew the circuits.
Aye, the Q29. I recall the first line. "S1 closes energising SA". Broder Tuff, the instructor, who is on the AMERES facebook page, says he can still draw the circuit!
There was a shortage of R/Os in those days and I got a job with BP Tankers without even an interview!
Such a book might be banned!


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## Old Se Dog (May 21, 2015)

*city of worcester*

enjoyed your post re the city of worcester and the europa here is what i believe the ship you sailed on is


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## IvortheEngine (Sep 2, 2016)

Old Se Dog said:


> enjoyed your post re the city of worcester and the europa here is what i believe the ship you sailed on is


That's the one Old Se Dog...lovely ship...did a triple header on her 23.10.74 to 22.9.75 (went home while she coasted the UK and rejoined for the next deep sea voyage).

Regards

Ivor


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## duncs (Sep 8, 2008)

I used the DF many times. On a Texaco VLCC, to rendezvous with a lighter in the Gulf of Mexico, in continuous overcast conditions, no sights for days, it was the DF/DR that put us spot on. Used it on the Irrawady entrance in thick fog, and was quite stunned when the OM(old time Bankliner), went with my bearings.
Also used it in a distress situation. It proved very helpful.


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## Troppo2 (Jun 25, 2018)

spaarks said:


> Hi Bob. You must have been in a later class than me - I got my tickets in 64. At that time there was no Hermes, just a K-H as you say. The examiner put a superconducting valve in it which stumped everybody - but he talked us through it. I guess it was a good way to determine if we knew the circuits.
> Aye, the Q29. I recall the first line. "S1 closes energising SA". Broder Tuff, the instructor, who is on the AMERES facebook page, says he can still draw the circuit!
> There was a shortage of R/Os in those days and I got a job with BP Tankers without even an interview!
> Such a book might be banned!


Broder transferred to the Australian maritime College.


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