# D/F Correction Curve



## FuManchu (Jul 16, 2013)

Hello everyone,
I wondered if anybody could tell me what this is. I found it in a box of crystal radio bits and am intrigued as to what its purpose was.







Thanks in advance.


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## sparkie2182 (May 12, 2007)

Quite a tome..........but interesting.

http://km5z.us/files/RCA Radio Course/Lesson 69 - Radio Direction Finder or Radio Compass.pdf


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## King Ratt (Aug 23, 2005)

Having just read through all that. Hard to believe we had to know all that stuff to get our PMG cert. Phew!


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## stocksie (Apr 22, 2008)

The chart shown is mounted close to the MIMC 758 LODESTONE DF. It is made out at the time of the calibration of the DF.It shows bearings taken on the starboard quarter will need up to 3 degrees correction. The tanker? British Fern
may well have had fairly large assymetry on her starboard aft side. Typically 
pipe crane gear or added pump control houses etc. 
Errors like this could not be auto corrected and so Error curves were posted next to the DF. for reference when needed. The rotating loop DF described in lesson 69 had a very complex pointer advance or retard control system that 
needed many screws to alter the 360 degree forward backward mechanical
position of the pointer. A nightmare to set up I imagine!


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## sparks69 (Dec 18, 2005)

That brings back memories of trying to get the OoW to help get some check bearings before we hit port. 
DFs were great pieces of kit but chronically under used in the days before Sat Navs.
I can always remember the mate coming in the shack one evening on the way up to Iceland and asking if that set of bearings I took in the afternoon were any good as the O/M had altered course on the strength of the position I put on the chart. (We didn't run aground on Iceland - thank God !)
Happy Daze


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## Naytikos (Oct 20, 2008)

FuManchu: What you have is a nice souvenir from the BP tanker, British Fern.

All ships over 300grt used to be fitted with a receiver for radio-direction-finding. By taking the bearing of the signals from fixed shore radio beacons the ship's position could be plotted on a chart.

Once a year the calibration of the DF receiver had to be checked and a graph prepared showing any errors. That is what you have.


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## FuManchu (Jul 16, 2013)

*Thank you*

Fascinating stuff chaps, brilliant, thank you very much.


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## trotterdotpom (Apr 29, 2005)

Sometimes it was quite difficult getting the co-operation of deck officers when check bearings were required. Opportunities only presented themselves occasionally and often it wasn't convenient due to coastal navigation duties. Surprisingly, I don't ever remember "flogging" the check bearings and it would have been very easy. Are the modern generation as conscientious as us? Hope so.

A lot of the navigators thought the DF was there so they could wig in to broadcast stations - that's why it was always de-tuned from the distress frequency of 500 kcs where it was supposed to be set. If the DF was set on 500 kcs and the auto alarm in the radio room was activated by a Distress Signal it would automatically take a snap bearing of the location of the distress, but you couldn't stand guard on the DF 24 hours a day so that feature was a waste of time.

John T


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## david.hopcroft (Jun 29, 2005)

Check bearings were fairly easy when heading up the S.African coast from Capetown. The tide ran close inshore so with deep water, it was always the choice course. You could always see the lighthouses with DF stations quite easily. With the tidal flow well offshore in the other direction, you had to make do with one-sided checks. We did log in for berthing at Durban then dropped back to Cape St Francis to swing the ship for a 360 check. Must have been a survey due !

David
+


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## John Briggs (Feb 12, 2006)

trotterdotpom said:


> Sometimes it was quite difficult getting the co-operation of deck officers when check bearings were required. Opportunities only presented themselves occasionally and often it wasn't convenient due to coastal navigation duties. Surprisingly, I don't ever remember "flogging" the check bearings and it would have been very easy. Are the modern generation as conscientious as us? Hope so.
> 
> A lot of the navigators thought the DF was there so they could wig in to broadcast stations - that's why it was always de-tuned from the distress frequency of 500 kcs where it was supposed to be set. If the DF was set on 500 kcs and the auto alarm in the radio room was activated by a Distress Signal it would automatically take a snap bearing of the location of the distress, but you couldn't stand guard on the DF 24 hours a day so that feature was a waste of time.
> 
> John T


A very interesting post John. In all my time at sea I never knew that the D/F was supposed to be set on 500 kcs nor its function in conjunction with the auto alarm.

Mind you we were never given any training whatsoever on the D/F and generally found it a far from reliable navigation aid.


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## Ron Stringer (Mar 15, 2005)

John Briggs said:


> A very interesting post John. In all my time at sea I never knew that the D/F was supposed to be set on 500 kcs nor its function in conjunction with the auto alarm.
> 
> Mind you we were never given any training whatsoever on the D/F and generally found it a far from reliable navigation aid.


The interconnection between the auto alarm and the D/F was only relevant to the later, fully automatic D/Fs, such as the Marconi 'Lodestar' series. The older, manual Bellini-Tosi types and the rotating loop types were not suitable for such sophisticated arrangements.

D/F equipment, like many other devices, was only as good as the operator and was only accurate and reliable if properly maintained. I found it to be excellent and frequently a more reliable aid than snatched sights of a sun glimpsed through a fleeting break in the cloud cover, or against a vaguely-seen, 'guesstimated', horizon. I never sailed on a ship with Loran or Decca Navigator (other than a Decca Navigator temporarily fitted on one ship when on the North Sea coast of Europe and removed before going deep sea) and the D/F was much used when making landfalls. I never found it to be inaccurate if used sensibly and correctly.

On a bumpy, totally overcast, winter voyage from the St Lawrence to Grangemouth, via the Pentland Firth, the D/F showed us to be consistently diverging south of the intended track for some 36 hours before the radar picked up land. The Old Man and the mates were very dismissive. They were less bombastic when the radar eventually picked up a coastline and they found that we were over 40 miles south of the Butt of Lewis. 

No apologies were forthcoming, of course.


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## sparkie2182 (May 12, 2007)

Of course.

I wonder how many mates used the kit @ night??


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## Tony Selman (Mar 8, 2006)

D/F's were taken very seriously on the North Atlantic run. When I was with them Brocklebank Line R/O's manned the Cunard cargo ships (not passenger ships that came later). Although I loathed the run I spent quite a lot of time pounding across the North Atlantic and it was by no means unusual to not see the sun on a complete crossing in either direction. Approaching land at either end having crossed the pond on DR's meant that the D/F was a popular piece of kit. In general I was always impressed at how good the Second Mates DR's were but on Alaunia/GFQU approaching the South coast of Ireland on one trip around 1966/67 the Old Man refused to believe my D/F bearings which produced a cocked hat of about 3 or 4 miles in width but placed us about 40 miles from where we thought we were. I got a bit of flak but had no way of proving I was right other than taking several sets and passing them to the Second Mate without the Old Man knowing and they were consistent. When we eventually picked up the South of Ireland on the radar and cross checked against the D/F I was a couple of miles out. You will be amazed to hear that the OM did not apologise for challenging my capabilities.

You pays your money and takes your choice here. You can say that the D/F, and I, were not much good because we were a couple of miles out but my defence is that I was a lot closer than than being 40 miles out by DR and at least we did not hit Ireland. These bearings started about 200 miles out and finished as we came into radar range, say 40 miles. Even at that range an error of 1 degree makes quite a big difference when taking cross bearings. As any R/O who ever sailed will tell it is hellishly difficult to feel confident to an accuracy one 1 degree when trying to identify the null of a bearing unless you are very close.
I always felt that a D/F bearing bearing properly taken gave you a very good idea of where you were but was not to be taken as a precise position.


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## trotterdotpom (Apr 29, 2005)

John Briggs said:


> A very interesting post John. In all my time at sea I never knew that the D/F was supposed to be set on 500 kcs nor its function in conjunction with the auto alarm.
> 
> Mind you we were never given any training whatsoever on the D/F and generally found it a far from reliable navigation aid.


As Ron points out, this facility only became available in later models of Direction Finders. Obviously it wouldn't work on a DF with a rotating loop (unless the RO slept hanging onto the wheel). However, even without the automatic function, the DF was supposed to be left on 500 kcs, the distress frequency, just in case it was needed.

DFs were eventually replaced by more accurate equipment like Decca Navigators and Satnavs, but, as has been pointed out, in their day, they had their good points. Latterly, their usefulness was further reduced by the closure of many shore DF beacons.

Deccas and Satnavs have no capability of locating a ship in distress, but DF, with all its limitations, has. That is the reason why the carriage of a DF was still a requirement. Two or three ships taking a bearing of a distress can obtain its position, and one ship getting a single bearing is better than nothing.

I tried to explain this to a lot of Mates but the response was usually along the lines of: "Duh! It's a load of crap anyway." A bit like trying to get Ships Nostalgia members to believe in climate change.

These days, of course, distress handling is shore based and the presumably the Mates listen to their iPods, so the old DF is probably consigned to history.

John T


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## YORKYSPARX (Mar 31, 2006)

The old Lodestone DF, when properly calibrated was an ideal peice of kit for landfall. On The Border Laird we had fog along the channel all the way. We navigated by hourly DF fixes, coupled to Consol bearings from Sttavanger Bushmills and Plonis, another unit that was not used very much by ships.


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## richardwakeley (Jan 4, 2010)

I did once use the Lodestone for it's intended purpose on 500 kc/s. On Cyclops, around 1972, in S. China Sea somewhere east of Vung Tau we got an SOS from a disabled Chinese (Panama flag) ship nearby. In heavy overcast and rain, we couldn't find the ship at it's given QTH. Myself and a couple of other European R/Os on nearby ships took his D/F bearing, exchanged them between ourselves and found him. Waste of time though, it was a timber ship with heavy list but didn't want to abandon ship.


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## Cisco (Jan 29, 2007)

I found it to be useful kit if you had patience and got a bit of practice using it to gain confidence. For many years there were 3 d/f beacons in the western approaches to Bass Strait transmitting in turn on the same frequency, I think it was Capes Otway, Wickham and Schanck. http://trove.nla.gov.au/ndp/del/article/68291873

Handy if coming in from the west after a week or so of heavy overcast.

I was once involved in a bit of distress stuff involving D/F east of Okinawa in about 1967. In heavy weather with a typhoon in the vicinitywe received an SOS from a panamanian log ship. US shore stations to the west of us took D/F bearings of both us and the log ship and fixed our positions in very short order. It then turned out that there were other ships closer so we proceeded on our way.


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## gwzm (Nov 7, 2005)

The Marconi Lodestone was a life saver for us on a coasting trip on Brocklebank's SS Manaar from Middlesbrough to Bremen across the North Sea in fog. The radar kept switching itself off and on at random every few minutes so it was switched off until it could be fixed. In the meantime the 2/O was navigating on dead reckoning and I was taking DF bearings which bore no resemblance to the DR positions. Eventually, according to the DF bearing positions, we'd passed the light vessel at the entrance to the Weser and were heading for the beach! The captain swung the ship until we had the light vessel "on the head" according to the DF and aimed for it until we established an accurate position and navigated from there. 
Brocklebank's SS Malakand had a Siemens swinging loop DF which was "interesting" to operate with its steering wheel and receiver hanging from the deckhead. That said, the DF check bearings which I took proved to be pretty accurate.

Happy days,

gwzm


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## Binnacle (Jul 22, 2005)

On passage Vancouver/Leith we ran into fog in the Western Approaches which lasted until after we had anchored in Leith Roads. The first I saw of the UK was Leith. We had no radar, had worked with DF bearings and soundings most of the time, had closed to identify several buoys and light vessels. I had the greatest respect for that "old man", he used all the nav aids available, and used them wisely. My only minor gripe about use of DF was a rather keen RO anxious to get a signature in his book so charges could be made, before we had a chance to lay off the bearings on a chart. His priorities were different from mine.


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## trotterdotpom (Apr 29, 2005)

When was that, Binnacle? What charges did you have to pay? I never heard of charges for DF bearings, in fact, how would a DF beacon station know you were using their signal? 

John T


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## Cisco (Jan 29, 2007)

trotterdotpom said:


> When was that, Binnacle? What charges did you have to pay? I never heard of charges for DF bearings, in fact, how would a DF beacon station know you were using their signal?
> 
> John T


I think that the coast d/f stations were d/fing you rather than you d/f ing them.
The cost of the service was listed in 'the book' as so many gold francs


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## trotterdotpom (Apr 29, 2005)

Cisco said:


> I think that the coast d/f stations were d/fing you rather than you d/f ing them.
> The cost of the service was listed in 'the book' as so many gold francs


Thanks Cisco. Now that you mention it, I vaguely recall Q codes for requesting a DF transmission from a Coast Station, but I certainly never used them. You make me feel young. I can imagine the RO trying to get signatures or whatever he needed, despite the annoyance to the Mates, any discrepancies would have come out of his pocket. Macaronis didn't care about the fog.

John T

PS When I worked on Nab Tower in Spithead we had a booking to turn on the DF Beacon for a DF calibration by Queen Mary (1), maybe her last transatlantic voyage - a bit of a novelty for us aboard the light. Presumably Cunard paid for that but we never saw any of the money. Being realistic, it was only a matter of flicking a switch, so what the hell.


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## Dickyboy (May 18, 2009)

trotterdotpom said:


> As Ron points out, this facility only became available in later models of Direction Finders. Obviously it wouldn't work on a DF with a rotating loop (unless the RO slept hanging onto the wheel). However, even without the automatic function, the DF was supposed to be left on 500 kcs, the distress frequency, just in case it was needed.
> 
> DFs were eventually replaced by more accurate equipment like Decca Navigators and Satnavs, but, as has been pointed out, in their day, they had their good points. Latterly, their usefulness was further reduced by the closure of many shore DF beacons.
> 
> ...


"As Ron points out, this facility only became available in later models of Direction Finders." 
Are you intimating that John Briggs is too old to have had dealings with later models of DFs? (Jester)


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## trotterdotpom (Apr 29, 2005)

Dickyboy said:


> "As Ron points out, this facility only became available in later models of Direction Finders."
> Are you intimating that John Briggs is too old to have had dealings with later models of DFs? (Jester)


Not me Dickyboy, that was Ron ... sez he passing the buck.

John T


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## John Briggs (Feb 12, 2006)

Maybe it was part me being too old but the larger part was the old ships and equipment.


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## Binnacle (Jul 22, 2005)

trotterdotpom said:


> When was that, Binnacle? What charges did you have to pay? I never heard of charges for DF bearings, in fact, how would a DF beacon station know you were using their signal?
> 
> John T


Only about sixty years ago. I think Cisco has the answer. If Marconi charged the R/O if no signatures were obtained then I can understand his enthusiasm. What I do remember is there were about three or four sheets of carbon in his chitty book, so Marconi certainly had it in black and blue.. The last DF I sailed with, about twenty odd years ago was Japanese built, gyro compass stabilised, very quick response. A joy to use for our purposes.


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## trotterdotpom (Apr 29, 2005)

Thanks Binnacle .... something else that has passed into history. Even the carbon copies are consigned to the past now! You have to wonder what happened to all those copies- filed somewhere I suppose. Marconi's certainly took a dim view of accounts that didn't balance, so, naturally, they always did. A little bit of stress added to the devil-may-care sparkie's life.

John T


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## 7woodlane (Apr 20, 2009)

The d/f receiver was a useful piece of equipment, as most comments are positive about its ability. Never any doubt about its usefulness especially in foggy situations/night times when some OldMen panicked about the ship's position. Why panic ? I was no better than anybody else, but took bearings as instructed only to be told in sarcastic terms that I was wasting his time. So you slink off the bridge to be told later(usually the 2nd or 3rd Mate)... the d/f bearings were good. Apologies from Himself ? Don't make me larfff.


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## Ron Stringer (Mar 15, 2005)

Cisco said:


> I think that the coast d/f stations were d/fing you rather than you d/f ing them.
> The cost of the service was listed in 'the book' as so many gold francs


Certain coast stations offered a service whereby, on request from the ship, the coast station would direct the ship to transmit its callsign followed by one or more 30-second dashes on an agreed MF band frequency (usually 410 kHz). There was even a Q-code for it, which now escapes me.

Using the coast station's direction finder, bearings were taken of the ship and then the information would be passed to the ship's R/O. There was a charge for this service and I remember going through the accounting procedure in radio college, while preparing for PMG2 in 1958. That was the only time that I ever had anything to do with the service.


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## richardwakeley (Jan 4, 2010)

Was it QTG?


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## trotterdotpom (Apr 29, 2005)

richardwakeley said:


> Was it QTG?


Yes Richard. "Will you send 2 ten second dashes followed by your call sign?" i'm no Lesley Welch, I just googled it. There is also QTE? - "What is my true bearing from you" and QTF - "What is my position according to your bearings?"

How quickly we forget .... 410 kcs had disappeared from my goniometer conpletely.

Maybe Hawkeye and co can tell us if and when the coast station DF service finished. I've never heard of it being used until reading this thread, but no doubt there was a time when DF was thought of as a pretty Swish bit of gear and was used a lot.

I did use Consol in anger a couple of times - by the time you mis-counted the dots a few times and got it right, you were nowhere near where you'd started off from.

John T


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## John Briggs (Feb 12, 2006)

I missed all the foregoing excitement.
To me the D/F was an instrument to sometimes get music on when stuck with a boring anchor watch.


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## Ron Stringer (Mar 15, 2005)

John T (#8) and Sparkie (#12).

Briggsy was there! (#33)


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## John Briggs (Feb 12, 2006)

Ron Stringer said:


> John T (#8) and Sparkie (#12).
> 
> Briggsy was there! (#33)


Just being honest!


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## trotterdotpom (Apr 29, 2005)

Ron Stringer said:


> John T (#8) and Sparkie (#12).
> 
> Briggsy was there! (#33)


I know, he gave himself up. Sigh. That's why I gave up myself. I did get my own back by planting phoney telegrams for the 3rd Mates to read though.

John T

PS I think Sparkie's post was referring to the fact that "Night Effect" made DF pretty useless during darkness. Damn that ionosphere!


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## trotterdotpom (Apr 29, 2005)

R651400 said:


> If coastal fog or as East Coasters refer to it "haar" blanketed the coast line then your skipper on this occasion navigated up the Firth of Forth purely on soundings, buoys and fog horn signals from light-houses.
> DF bearings from Stonehaven and Cullercoats Radio(s) would've been impossible due to a DF error known as coastal refraction.
> More power to the elbow of your excellent skipper.


Presumably, if they were charging for the service, the transmitter aerials would have been close enough to the shore to negate "coastal refraction". I can't believe how much DF theory is coming back to me! Normally I just sit in buses looking down into cars at girls thighs .... Oh no, watch out for "Night Effect".

John T

PS that "haar" that you mention is known as a "fret" in Yorkshire. I remember once in the Channel, there was one of those thick surface fogs but the sky was blue and the sun was shining down. The Old Man was bleary eyed with a three day growth. I went out on to the bridge wing, looked up and said: "I see that visibility's down to 93 million miles today." Well, I thought it was funny.


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## Gareth Jones (Jul 13, 2007)

When I first joined GNF in the early 60's the older staff told me that the system of D/F installed there was the Adcock system. Four vertical antennae installed at great expense about a quarter of a mile away.
They said it worked very very well - even at night. 
It was barely installed before the GPO ripped it back out again. No-one knew why.


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## trotterdotpom (Apr 29, 2005)

R651400 said:


> What transmitting aerials?
> Stick to pulchritude there is obviously nothing left in DF theory!


Whoops sorry, R65 - You got me, I was thinking they were transmitting and the ship was taking the bearing. Obviously, the ship sent the dash and the coast station took the bearing. However, all the ships transmission was over water and I know from photos that Stonehaven at least was almost falling into the drink, ergo no coastal refraction. All before my time anyway. It was all a load of crap that we had to appease the radio surveyors with, but try and get that through to the Mates....!

Pulchitrude, now you're talking, I'm off for the bus.

John T


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## Robert Bush (May 18, 2006)

On my first command we had a good Radio Officer but no D/F, however the Rangoon River Pilot vessel did have D/F and her Master, a Captain Twoomey, would take bearings of our transmissions and send them to us. A God send in thick weather.


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## Klaatu83 (Jan 22, 2009)

This reminds me of the last time I had occasion to assist in checking the error on a Radio Direction Finder. The captain was in the chart-room taking the RDF bearings while I stood out on the bridge wing to take the corresponding visual bearings. We did it while sailing past the lighthouse on Sable Island, Nova Scotia, around 4:00 AM one frigid February morning during a blizzard. At the time, Sable island was one of the few Radio Beacons still operating in that region. Although the lighthouse on Sable Island shows a very bright light, better than 20 miles I believe, I couldn't see it though the driving snow. The captain said, "Well, stay out there until you do". I remained outside on that bridge wing until after we finally passed Sable Island, no more than 5 miles abeam. I never did see that light, not even the loom of it. It was an experience I will not soon forget!


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## trotterdotpom (Apr 29, 2005)

Who says they got bearings when they were in the Forth? I imagine they got them as they went past the station somewhere. I'm losing track here. didn't the original poster say the first land they saw was Leith? If they were charged for bearings when they were in the Forth the GPO should be charged under the false advertising rules or somat.

John T


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## Varley (Oct 1, 2006)

Isn't pulchritude a matter for the observer?


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## trotterdotpom (Apr 29, 2005)

R651400 said:


> I could be impolite and say you haven't a clue!
> You're obviously clutching at straws..
> Stick to pulchritude.


I'm not clutching at straws, you're just dragging it out for some reason. And you spelled pulchitrude wrong.

John T


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## Naytikos (Oct 20, 2008)

I seem to remember a DF station in Germany that could actually give Latitude and Longitude to any ship requesting it through DAN. It must have consisted of at least two receiving stations. Subject to the distortions of the passage of Anno Dominii I think it took 15 - 20 minutes to get the position back from DAN after sending the long dashes etc. Something tells me it had to do with the cleared passages through the minefields off the Weser and Elbe estuaries.


Regarding expressions of appreciation for direction-finding efforts: On Montreal City from the St. Lawrence back to Bristol in December 1968 the Captain, who I did not get along with at all, perhaps because I was only a relief R/O for that trip, came literally cap-in-hand (he used to wear it on the bridge!) to ask if I could possibly find out where we were as there had been no visibility for sights for four days. A combination of Consol and D/F bearings from Southern Ireland and France were sufficient.


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## trotterdotpom (Apr 29, 2005)

R651400 said:


> Yes you are and no I'm not when it comes to personal experience.
> By the way the word I'm thinking of is ... pulchritude.
> Pulchitrude..Webster's antipodean ocker banana-bender dictionary perhaps?


Whoops, you got me! My only excuse is I hadn't heard the word until last week. 

John T


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## bluemoon (Jul 19, 2009)

John, for the life of me I cannot remember there being a D/F on any SSM ships.

Probably just my poor memory - can you throw any light on the subject?


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## Ron Stringer (Mar 15, 2005)

Must be your memory, bluemoon. The carriage of D/F was mandatory.


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## trotterdotpom (Apr 29, 2005)

bluemoon said:


> John, for the life of me I cannot remember there being a D/F on any SSM ships.
> 
> Probably just my poor memory - can you throw any light on the subject?


You might remember a couple of tin rings at right angles to each other up on the monkey island. They were connected to a wireless on the bridge. There were two dials on the wireless - one didn't seem to do anything and the other could find the BBC.

They were definitely there, if you don't believe me ask R65.... , he's the expert.

When were you with SSM?

John T


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## MikeK (Jul 3, 2007)

John Briggs said:


> A very interesting post John. In all my time at sea I never knew that the D/F was supposed to be set on 500 kcs nor its function in conjunction with the auto alarm.
> 
> Mind you we were never given any training whatsoever on the D/F and generally found it a far from reliable navigation aid.


Ditto !


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## expats (Mar 9, 2013)

In the late 1960s I contracted Sarcoidosis and required regular hospital visits...Marconi were excellent employers and paid for me to take the BOT radar course and, allowed me to become 'coastal relief' for the next few years....
The attitude of 'Deep Sea Skippers' when near land usually meant, in poor visibility, every nav aid (including DF) was used. Coastal skippers on the other hand only seemed to worry, and want DF, when well out of sight of land...

Horses for courses...


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## Binnacle (Jul 22, 2005)

I was mate on a ship when a radio surveyor appeared at my door shortly after arriving at Grangemouth, I invited him in to join me for a cup of coffee and nipped in to tell the second mate to keep him happy while I nipped up to the chartroom and removed two cartons of cigarettes from inside the D/F set. It was rather stressful as I had passed several members of HM black squad on the way up. I was afraid that the surveyor might take a dim view of my choice of hidey holes, especially if he was a non smoker. It was an old valve set, wooden cased, all screwed up to the deck head, complete with car type steering wheel (Austin Ruby ?). Probably a Marconi Mk 1 for the technically minded.


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## trotterdotpom (Apr 29, 2005)

R651400 said:


> I'd be happy to reply in kind.
> Once upon a time there was a degree of purity to SN and its subject material ie MN and/or seafaring.
> Now SN seems to have been hijacked by members without any profile eg in the case of bluemoon giving their location as toytown!
> Sorry if there is no response from this ilk but maybe as a fellow company man trots you can tell us where the eff toytown is?
> ...


I used to have a fairly expansive profile on SN but I was advised against it because of Internet monkey business, so I replaced it with a minimalist version. Despite that, I think I'm a fairly open book due to my postings. Maybe Bluemoon thinks the same way. I think he's a recent arrival so we'll have to wait and see.

SSM, a pretty good outfit that emerged after your time, was a Scottish company and full of Scotsmen so there's a fair chance that Toytown is in Bonny Scotland, as are you, going on your profile. You'd have more idea on its location than I would. Why not tune for a minimum?

John T


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## 8575 (Sep 8, 2006)

As a deck officer I found D/F to be a very valuable piece of kit and used it on many occasions, once when proceeding down channel from Rotterdam to Atlantic; dense fog all the way, radar not working - used it to obtain cross bearings from the grouped D/F stations along the south coast of England and when vis eventually lifted we were very close to where the D/F fixes said we were. The collision avoidance on the same passage was much more eventful however!

Another occasion I used it to cross a position line from the sun and despite the scoffing from the Mate we were nearly dead on where we thought we were.

Am I right in thinking you could use it with Consol as well? I'm sure there was a transmitting station in NW Spain (Vigo?) and another in France (Ploneis?).


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## Robert Bush (May 18, 2006)

Agree with Waighty # 62

The Japanese had some well located D/F stations covering their southern coast lines.

Used a bearing taken by my Chief mate who had a good ear to go into St. Pierre in very thick vis.


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## trotterdotpom (Apr 29, 2005)

Probably I was being paranoid about not putting too many details on internet profiles, but why take chances?

I worded my post badly, rather than "tuning", I should have said swing the goniometer pointer for a minimum signal, but as you politely pointed out, I haven't a clue, so, what the hell?

I suspect Bluemoon said he was from "Toytown" with humourous intent. What difference does it make where he lives anyway?

John T


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## Varley (Oct 1, 2006)

Binnacle said:


> I was mate on a ship when a radio surveyor appeared at my door shortly .... Probably a Marconi Mk 1 for the technically minded.


We were taught that Marconi had got the patent or patent rights for Bellini Tosi static loops and so your rotating single loop DF may very well have been made by A.N Other (I suppose a very,very stiff goniometer might have needed a handwheel).


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## david.hopcroft (Jun 29, 2005)

My last two ships had a fixed loop DF that had the AEI badge on it. That was in 1965-7 so the patent must have run out before then. Prior to that it was rotating loop which was very good but hard to keep still on a wet and windy night !

David
+


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## johnball59 (Aug 13, 2013)

Hi
I did this regularly as a Radio Officer If in a year a certain amount of bearings had not been verified by the R/O and the Bridge then a full recallibration was required by the DOT. There was a radio beacon you would swing the ship around it a full 360 degrees taking readins at regular intervals in conjunction with a deck Officer and that chart was produced as an error chart. The direction finding equipment could be used in poor visibility to get a bearing from a fixed known point and hence give the deck officer something to work with. You would take the reading from the instrument then apply the correction from that chart you found hope that helps


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## Wismajorvik (Dec 29, 2011)

A couple of items came to mind.
On one vessel which started to leak, ( concrete patch in the bow breaking up) while heading back to the UK in the Bay of Biscay in heavy weather the skipper had to make various course alterations to keep the stern into wind. Lost at sea. Once Ushant came into view, the position obtained through the d/f bearings I had taken proved far more accurate than the 2nd Mate's DR.
Earlier in the voyage, from Capetown to Dakar, the gyro repeater on the d/f started chattering while I was on watch. A quick look out of the port showed the sun rotating about the ship. A query to the 2nd.mate as to why we were heading back to Capetown resulted in a quick dash by him to manual steer as the auto pilot had gone **** up.


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## Ian Beattie (Mar 28, 2013)

I remember sailing on the "Mountpark" from Baltimore to Hokkaido it was a bulker and we were loaded with coal. Just getting to the vessel was a whole story in itself (for another time perhaps), but soon after sailing the main TX broke down it was a Crusader and fault traced to the output bottles guess what no spares, lots of begging QSO luckily there were some decent guys around. Half way across the Pacific the Argus radar goes awol so found the fault again no spares and it was a simple resistor swap, I couldn't even cobble anything together not even with araldite. Approaching Japan thick fog real pea souper, so here is me sending TTT messages every 15 mins with our position speed etc. The positions were all obtained from D/F which I duely passsed to the bridge every time the chain became active. The Skipper was Capt Tawse and both he and I did 48 hours straight and brought the ship into bouyage safely - the D/F results were spot on as verified by the coastal wallahs at later time. No sooner tied up and the fog vanishes. So I can assure all you non believers that if used properly it can be very accurate and in this case a bit of a life saver. That was the one and only time I got p***ed with the Skipper while at anchor or even at sea - he said we deserved it - maybe he was right. I didn't refuse it would have been churlish. Unfortunately I heard that the Skipper died about four months later what a real shame as he was a top bloke and no mistake.
Cheers Ian


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