# Dieckmann & Klapper MAS 140 Aerial (2)



## R651400 (Jun 18, 2005)

I've been kindly giving permission by Ernest Erb the founder of website Radio Museum http://www.radiomuseum.org/ to publish this diagram of the Dieckmann & Klapper MAS 140 antenna that was fitted to mv Derbyshire. 
I'm principally interested in any practical experience or additional theory behind this antenna eg if there was any part of the central fibre-glass supporting mast that could have added to it's radiational properties ie a central spiralled copper or aluminium foil within the core. 
There are other SN threads on this antenna for reference but preferred to start afresh with the hope of further new input.
My German is hardly basic Reeperbahn ie next to zilch so perhaps someone may help with a technical translation of the various sections.


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## Tony Selman (Mar 8, 2006)

Malcolm, my wife speaks fluent German so I will get her to have a go. Technical German is much harder than conversational though. Will let you know.


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## Tony Selman (Mar 8, 2006)

'Bloody Hell' was her first reaction so this may take a while!


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## R651400 (Jun 18, 2005)

Thanks Tony. Bing was completely useless on anything I tried. 
Apart from the fact that "Derbyshire" carried this as it's main antenna am actually intrigued if the dangling threads are it's only radiators and why anyone in their right mind would install this monstrosity particularly on a ship that would experience wx wind forces to hurricane force.


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## avide (Mar 1, 2013)

Forget Bing, use Google instead. Their Translator's light years better.
And here it goes, all using Google's Translator:
detail A 
1. carrier-mast
2. mast head 
3. roof capacity complete (maybe top-level capacitors would be better?)
4. nut holder for fitting roof capacity (see above)
5. antenna rod (there's a typo in German paper, it should be antennenstab)
6. coupling nut for rod antenna
7. laminated conductor of the antenna rod (another typo, should be einlaminierten...)
8. rod antenna fitting (once more "..srab" instead of "..stab")
9. sealing ring
10. PTFE part (maybe zone, but IMHO part is better)

detail b
3. roof capacity complete
5. linear traps (translator on Reusen Seil gives traps rope and this should be a trap so linear traps is probably the best answer)
6. supporting rod

13. closed span
14. guy wire ring
15. grommet
16. linear trap connection by terminal cable lug
17. bell (?) maybe something like bell jar or bell-like part
18. strain insulator
19. shackles
20. feed line trap
21. introduction insulator (maybe feed insulator could be better)
22. mast foot (I don't know if it's correct in English but in Polish that lowest part of a mast is called "stopa" = foot. Maybe the same rule applies  ).
23. internal feed line
24. insulator bracket
25. bushing (but in Polish we use term that can be translated like "pass through insulator").
26. PTFE part (see above)
28. interception line with shackles
29. insulator for external feeder 

*) omitted if external feeding is used

I don't know if it's correct, but for sure it's easier to understand this way 

And the main question is... 
How this antenna could survive really hard weather, something heaver that 11B? IMHO - no way.
I've read some stories when radar scanners - solid as hell - were destroyed.


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## R651400 (Jun 18, 2005)

Thanks for that Avide including your final comment on it's ability to or not to withstand hurricane force winds.
The other question I would like to pose and maybe Ron Stringer can oblige? 
If this was the main aerial for an all-aft accommodation ship such as Derbyshire what would be the Mimco requirement and placement of the emergency aerial?


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## Ron Stringer (Mar 15, 2005)

R651400 said:


> The other question I would like to pose and maybe Ron Stringer can oblige? If this was the main aerial for an all-aft accommodation ship such as Derbyshire what would be the Mimco requirement and placement of the emergency aerial?


Regrettably MIMCo could only make recommendations to shipowners and they in turn decided how much to spend on antennas and supporting structures. I have no personal knowledge of the antenna arrangements for the "Derbyshire" and most MIMCO drawings were destroyed in the 1990s. What remained were transferred to the University of Oxford. 

Generally it is true to say that MIMCo preferred to use a traditional wire antenna in 'L' or 'T' configuration for both main and emergency antennas, suspended from masts, samson posts or similar structures. Self-supporting mast antennas were only supplied at the customer's expressed request. At 500kHz nothing worked as well as a high and long antenna. Bear in mind that, pre-GMDSS, it was MF performance that mattered in emergency; HF performance only came into consideration for commercial communications.

Sorry I can't help.


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## R651400 (Jun 18, 2005)

Thanks for above. Blue Funnel was much the same but either way main and emergency aerials had to satisfy the SOLAS regs of the time. 
I wasn't specifically asking for what Bibby did but what was the Mimco norm for all-aft accommodation ships which became norm in ship design in the mid sixties.
The Japanese always had triangulated sub-masts on the poop for wire aerial support but I've never seen this on any British build.


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## Ron Stringer (Mar 15, 2005)

R651400 said:


> The Japanese always had triangulated sub-masts on the poop for wire aerial support but I've never seen this on any British build.


Generally we made do with what we were given. I do remember a couple of all-aft bulkers ("Sheaf Wear" etc.?) where the owners and the yard refused to put up such masts and, as a result, had the main and emergency transmitting antennas running down from the top of the funnel to a couple of 2.5 metre poles welded to the rails on the port and starboard quarters. On HF this resulted in a virtual "blind" area forward of the beam and the R/Os complained that homeward bound from South or Central America, they had to ask the Old Man if the ship could be turned through 180° so that they could get traffic away to Portishead.


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## R651400 (Jun 18, 2005)

It's hard to believe that all round radiating efficiency didn't come into the equation with this attitude and Mimco or whoever was responsible for the radio installation accepted.
Single R/O Japanese coasters of a reasonable size all had the triangulated masts fitted aft and for ship-spotters then the hallmark of a Japanese build.
Emergency aerial to samson-post was also debatable with the possibility of minor "collision whip" and I remember being instructed by BF to change from "L" type aft samson-post to the funnel to a "T" suspended from funnel not as efficient but certainly more robust.
At least with Blueys there was plenty height!!


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## Ron Stringer (Mar 15, 2005)

R651400 said:


> It's hard to believe that all round radiating efficiency didn't come into the equation with this attitude and Mimco or whoever was responsible for the radio installation accepted.


As I said, MIMCo had to put up with whatever the customer was willing to provide in the matter of suspension points for antenna. We could recommend whatever we liked but the customer could (and often did) decline to accept our advice. We then had the alternative of accepting their provisions or refusing the contract. Since the customer was always right, and the regulatory authorities had no specific radiation requirements, we had no other alternative. As long as the current into the antenna and the height of the antenna above the waterline produced the appropriate metre-amps figure, the ship was accepted at survey. After that it was a matter for the shipowner and the R/O (not the radio supplier) to handle traffic and deal with emergency communications as best they could manage.

Safety at sea? What safety.

There was no UK requirement to measure or achieve any radiation pattern or range for 500kHz installations. Maybe some time prior to my time at sea there might have been experiments to discover the range achieved from T- or inverted L-shaped antennas and to correlate the results with the metre-amp figures required by statute but there were no such tests done in my time.

Some time, late 1960s/early 1970s, I spent time with engineers from the marine equipment type approval department of either the GPO or its successor the Ministry of Posts and Telecommunications, sitting out on Trevose Head in North Cornwall taking field strength readings of MF transmissions from a passing ship equipped with MIMCo 37-ft stainless-steel whip antennas and from ships with wire antennas. This was part of an investigation as part of a UK submission to CCIR on the suitability of using such antennas on ships and to justify the formula that the UK applied to adjust the metre-amps calculations when surveying ships with whip antennas. 

We found out that these whips worked much the same as any vertical 11 metre metal pole would be expected to do on a frequency with a wavelength of 600 metres - i.e. pretty poorly. Those tests (the only ones carried out by the UK maritime authorities of which I am aware), together with other tests that we carried out elsewhere, showed that the whips worked best if mounted in a relatively clear site, such as at the top of a samson post or stub mast. In such situations they were about as good as a wire, 11 metres long, running vertically up towards a triatic stay. Rubbish on MF but OK on some HF bands. 

Mounting whips on the side of the funnel, as most shipowners preferred, was the worst location. We presumed that this was because that huge area of metal immediately adjacent to the antenna simply absorbed much of the radiation.

It all made sense but some owners were adamant that they would not agree to suspended wire antennas and refused to accept anything but whips, which were far less expensive than mast antennas such as the MAS140 or the AS-9. It was their ship, there was no regulation to forbid it, so they got their way.


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## avide (Mar 1, 2013)

One engineer from Polish MORS company (that produced and serviced marine radios) has done experiments with vertical rod antennas that were fitted with top level capacity, traps and a set of loading coils. You know - one rod for all bands. This company did also V/m measurements and so on during the tests.
Ron is 100% right - it was rubbish on lowest bands, but could perform quite well at 22MHz (could be even better at 28 (A) but it's a ham band not a marine one). No need to say that in these years 5 ton and 2182 were the most important bands for Polish ships in Baltic Sea.
Performance of that rod at MF and 2182 range was so poor, that entire project of single rod antenna for all bands went down the drain within a few months. I've heard a story that one of the sparks that participated in a test couldn't reach Gdynia Radio from The English Channel on 2182 at circa 100W of power delivered to that crappy rod. At the same time 50W was more than enough to do the same task with "L" or "T".
One of the antennas also has gone to hell in heavy weather - sparks noted that whole antenna was cracked and then wiped from a fantail. Main "L" antenna survived storms well because its elastic. That makes a big difference.


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## duncs (Sep 8, 2008)

Re D-K, my memory is poor(as seen in previous thread, re name). I was waiting for others' input. Did the lead in insulator go through the radio room deckhead, directly through the centre of the antenna pedestal, then through the mast to the outside wire, with no radiator within the mast itself, till it was connected externally, to the top whip? I vaguely remember this, when lowering it for maintenance, but I will stand corrected. In N atlantic, heavy wx, lost emergcy antenna(wire). Then main went(D-K). The wire broke where it enters the mast.(see dwng). Had to shinny up mast, tie myself to it, then fix with bulldog grips(fixing the main, was the best option). Apart from bleeding ears(from my jacket collar flapping), plus the OM left a bottle in my room, all was OK. This was a MIMCO installation with conqueror tx, which I found good all round. I found it good on MF especially.
D


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## R651400 (Jun 18, 2005)

Vertical and horizontal trap aerials have been around for aeons especially on harmonic HF bands such as amateur and one wonders why this was never adopted as a separate and more efficient aerial for the marine HF bands 4/22 mc/s. 
MF 405/515 kc/s by sheer physical size it's understandable trap verticals were a non-starter and makes the D&K MAS 140 (whatever the theory behind it) radiate reasonably well over the MF/HF marine spectrum. 
The only large scale successful MF/HF vertical aerial at sea I can think of was probably ss United States/KJEH's aluminium signal and lookout mast.

Two more links to D&K MAS 140 aerial accessories..

http://www.radiomuseum.org/r/dieck_klap_antennen_verlaengerungss.html

http://www.radiomuseum.org/r/dieck_klap_antennen_verlaengerungss_2.html


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## duncs (Sep 8, 2008)

Theories are theories, but practice is practice, and regardless of what sort of wire coat hanger have up there, you,ve got to do your best, M/F or H/F.


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## SparksG1714 (Oct 23, 2009)

R651400 said:


> Vertical and horizontal trap aerials have been around for aeons especially on harmonic HF bands such as amateur and one wonders why this was never adopted as a separate and more efficient aerial for the marine HF bands 4/22 mc/s.


<snip> 

Tried this (bored when held up in Lagos) for a trap wire 12/16/22 centre fed horizontal dipole but even alongside, over even a short period of time the traps were leaking due salts. As a receiving aerial though the improvement was massive.
Given that the majority of QRN is vertically polarised, the s/n achieved was remarkable over the bit of wet string normally given to receivers.
And for GKY2 the contacts were a delight, more like VHF than HF

Given the long QRYs on GKI (that then was) I'm surprised more wern't invited to QSY up to 25MHz

Later did some field trials with some 100W ham gear running up to a base autotuning unit feeding a wire. ZSD to GKY2 in one hop, just an hour before sunset to about an hour after. Pielstick main engines with some very involved faults in the control circuitry which Chief, Leccy, and techie from the control electronics firm and their head office did on keyboard to keyboard


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## R651400 (Jun 18, 2005)

Possibly the only ship-board Dieckmann & Klapper aerial still fully operational.

http://www.amrumbank.de/jupgrade/

ps Why is it the Germans and others are so good at floating maritime museums and we lag behind them all?

```

```


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## david.hopcroft (Jun 29, 2005)

As I have said before, I sailed with a DK for 2 years. I was well aware of its limitations on 500, but I am, by now, beginning to think 'did I just get lucky then ?'

This is the CAP SAN DIEGO, a museum ship in Hamburg. It has some sort of DK very visible.

http://www.shipsnostalgia.com/gallery/data/510/medium/IMG_0001186.jpg

David
+


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## R651400 (Jun 18, 2005)

My first experience of this antenna mention above was seeing it on board Norwegian Wilhemsen's Tagus in the late 50's and was Scandinavian made not Dieckmann & Klapper. 
I can only guess that the umbrella-type top is similar to a capacitance hat artificially increasing the aerial's length to give it MF/HF coverage.


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## duncs (Sep 8, 2008)

david.hopcroft said:


> As I have said before, I sailed with a DK for 2 years. I was well aware of its limitations on 500, but I am, by now, beginning to think 'did I just get lucky then ?'
> 
> This is the CAP SAN DIEGO, a museum ship in Hamburg. It has some sort of DK very visible.
> 
> ...


Can you remember if the lead in insulator, through the deckhead, went into the DK internally, or is this only my wonky memory. This would explain good perf on MF in humid conditions that I experienced.
Rgds Duncs


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## david.hopcroft (Jun 29, 2005)

There was a lead in insulator on a moulding near the base on a level with the bottom copper circle. The circle was connected to the top of the insulator. The DK was directly above the Radio Room and I think I remember the main & emergency leads coming in through the deck head as normal then into the aerial distribution box.

The PDF in R651400's #1 shows this. So yes, it went into the DK internally for the last 2 or 3 feet above the deck.

David
+


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## Troppo (Feb 18, 2010)

Ron is spot on re the lack of FS requirements for MF.

As long as the ship met the metre amps requirement, that was it.

I remember the Japanese "radio survey" on a new build Aussie tanker - the surveyor got me to QSA/QRK the local MF station....who was about 2 km away!

That was it! No measurements of rx sensitivity, etc.....

I spent the rest of the survey arguing about the validity of my General Cert with the idiot surveyor... he didn't want to accept it....he wanted a 1st class! Dickhead.

Hopeless.


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## Troppo (Feb 18, 2010)

When I was a surveyor, we conducted a series of FS tests at 1 nm on 2 MHz from GMDSS ships. 

What was amazing was the loss through the old antenna switch boxes....at least 20dB down on a whip with the ATU directly underneath...


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## avide (Mar 1, 2013)

Troppo, you're right! At least 20dB. One of the engineers that measured field strength in early GMDSS installations have discovered how bad it was. If one has to match Z=50Ω from Tx to 5Ω-j500, a typical lowpass PI filter will give about 12dB losses on matching (calculation based on 14MHz amateur band, QC=1000, QL=200). It's the worst case, unfortunately sometimes seen on a ship these days.

Then the feed line..
If a feed line has Z=50Ω but it's working with SWR=3 that's tuned on a PA stage, this feed line will loose additional 1,1 dB per every 10m of cable. And you don't know how much power goes out to the air until you measure FS.
That's why some small ships had quite a strong signal on MF/HF - their main "T" antenna was connected with a very short feed line from integrated Tx with built-in antenna switch. No ATU required, no additional loss, no problem.

Low power, high loss
I was told that this was the main problem with low power Tx such as an Oceanspan or some sort of Elektromekano. Not only low power from Tx but high loss on switches, feed lines and antenna connection. If you could just connect a good antenna directly to Oceanspan's output and tune it, difference would be impressive.


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## trotterdotpom (Apr 29, 2005)

Why would the surveyor want a 1st Class Cert for a poxy tanker? A 2nd Class would have done, even before General came about.

I remember when "Z" used to mean "Impedance" ..... now it just means Zzzzzzz, thank God.

John T


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## M29 (Apr 20, 2007)

Hi all
Like some of you, I sailed with D & K aerials quite a lot. "English Bridge" sister to Derbyshire was fitted with one and I did the trials and maidens on this ship. Like many of Bibby's new building at the time she was an all Redifon fitted ship.
On a wet February day on NE coast around 4pm, Bibby's Radio Super expressed his doubts about the performance of the D & K. I tuned up on 8MHz and called New York just once on r/t and got an instant reply!
I can say that I never had any problems using this aerial, also it was higher that a traditional wire and its performance on m/f never gave any concern.
I also sailed on the Dart Container ships fitted with D & K but these were all MIMCO radio rooms.
You had to keep an eye on the vertical wires which were tensioned by bottle screws. If these wires becames slack, the lack of tension could allow the rods that make up the cage at the top of the aerial to come adrift.
Dart America, when I joined her had loose rods and also the top whip was missing. The aerial was repaired during the annual drydocking.
Some D & K's were bolted straight to the deck, others were fitted to a winding gear that allowed the aerial to be lowered (e.g. Great Lakes trade with low bridges) I smiled at another contributer who remembers that this operation seemed to take for ever! 

Best Wishes

Alan


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## M29 (Apr 20, 2007)

R651400 said:


> I've been kindly giving permission by Ernest Erb the founder of website Radio Museum http://www.radiomuseum.org/ to publish this diagram of the Dieckmann & Klapper MAS 140 antenna that was fitted to mv Derbyshire.
> I'm principally interested in any practical experience or additional theory behind this antenna eg if there was any part of the central fibre-glass supporting mast that could have added to it's radiational properties ie a central spiralled copper or aluminium foil within the core.
> There are other SN threads on this antenna for reference but preferred to start afresh with the hope of further new input.
> My German is hardly basic Reeperbahn ie next to zilch so perhaps someone may help with a technical translation of the various sections.


High, further to my last posting, the diagram of the D & K in your post is not correct in all aspects. Missing from this diagram are the rods that run from the point were the wires attach to the top of the aerial down to the mast in a triangular fashion. In other words, a structure that is the mirror of the top part of the diagram. Thus a triangular cage is formed. The wire tension pulls against these rods. In the diagram shown, the top frame would just colapse as there is nothing to hold it up. The picture in the other thread on D & Ks shows the structure quite well.

Best Wishes
Alan


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## david.hopcroft (Jun 29, 2005)

This is the picture Alan refers to (I think).

The top arrangement is different from that shown in the pdf earlier. The top 'diamond' shape was rigid as far as I remember, and had 6 points, each connected to a ring at the bottom. This then went to a lead-in insulator on the mast and down into the aerial distribution box in the Radio Room directly below. There were no tensioners or like, but I never remember having any trouble with anything breaking. This particular ship could roll on wet grass, and 'pound' in to long swells when light ship southbound to SA, so all-in-all, I guess it was a pretty solid structure.

David
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## R651400 (Jun 18, 2005)

M29 said:


> ... I sailed with D & K aerials quite a lot. "English Bridge" sister to Derbyshire was fitted with one and I did the trials and maidens on this ship....


Thanks for posting your D & K experiences Alan. Can I possibly ask what was the emergency aerial on the "English Bridge?"


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## Troppo (Feb 18, 2010)

That antenna would go like a rocket on HF. A nice big vertical. Looks like a half wave on 8 MHz.

The AS9s I sailed with always went well on HF.


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## M29 (Apr 20, 2007)

R651400 said:


> Thanks for posting your D & K experiences Alan. Can I possibly ask what was the emergency aerial on the "English Bridge?"


Hi
As I remember, it was a traditional wire, all the receiving aerials were whips.

Alan


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## M29 (Apr 20, 2007)

david.hopcroft said:


> This is the picture Alan refers to (I think).
> 
> The top arrangement is different from that shown in the pdf earlier. The top 'diamond' shape was rigid as far as I remember, and had 6 points, each connected to a ring at the bottom. This then went to a lead-in insulator on the mast and down into the aerial distribution box in the Radio Room directly below. There were no tensioners or like, but I never remember having any trouble with anything breaking. This particular ship could roll on wet grass, and 'pound' in to long swells when light ship southbound to SA, so all-in-all, I guess it was a pretty solid structure.
> 
> ...


David
Yes that is the picture, it shows the "diamond" cage quite clearly. The lower supporting rods of the cage had hollow ends that fitted over spigots on the collar around the mast. These had the potential to come off if the vertical wires became slack.

Best Wishes

Alan


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## chadburn (Jun 2, 2008)

Also known as a "Cat Cage" when fitted to a Russian "Merchant Ship", a double set up was known as a "Cat Cage A"


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## david.hopcroft (Jun 29, 2005)

Thanks Alan. I have to say I didn't have any problems with breakage though. The sad part is that I can't remember the config of the emergency aerial. It can be seen on the post above the lifeboat. There was also another post on the other side of the bridge deck and this shows it could do. (this is also my desktop background !) but cannot remember how it entered the Radio Room (behind the bridge). Maybe via a lead in above the windows.

David
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