# MAS-20 MF/HF transmit aerial



## Mimcoman (May 18, 2008)

I wonder if anyone has information on the above transmit mast aerial, which I sailed with on T&J's Strategist and Specialist. It consisted of a white fibreglass support mast with a tubular metal cage at the top and a set of wires from the cage to a metal ring near the base of the mast, all adjusted using turnbuckles. There was a whip mounted on the top of the cage which extended the operating range, but I can't remember if it was for HF or MF.

I can't find any info on the 'net, but I believe an amateur radio club station at a port in the Netherlands or maybe Denmark uses one.

No particular reason for the info; just nostalgia.... http://www.shipsnostalgia.com/images/smilies/shar.gif

(Maybe we could have a thread about the wierd and wonderful arrangements we met up with for working the world. I remember hearing of an oilrig which had its transmit aerials mounted under the drilling floor.)


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## M29 (Apr 20, 2007)

Hi MIMCOMAN
Had a great deal of respect for this aerial. It was a main aerial and was used for both mf and hf. It was particularly good at 8MHz.

As you say, it had a whip on top and the full installation also included a "winding" gear at the base to allow the mast to be lowered to the horozontal for maintanence, low bridges etc.

I sailed with this aerial on several ships and was always impressed by the performance.

You had to be careful to ensure correct adjustment of the bottle screws on the veritical wires, otherwise, the tubular cage at the top of the mast could fall apart.
"Dart America/GOOB" lost the whip from the top but it did not seem to change the performance!

Regards

Alan


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## trotterdotpom (Apr 29, 2005)

I sailed with two of these that packed in, had to replace something or other, forget what. Quite a long job winding them down and up again.

A lot of German ships seemed to have a 'wagon wheel' up a mast for their main aerials - trouble free as far as I recall.

John T.


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## Buoy (Nov 29, 2006)

We used to have these in the P&O BSL ships in the mid '70's. I have just uploaded a picture of one in Kildare which you can see in my gallery, in the 'Life On Board' section or at: 

http://www.shipsnostalgia.com/gallery/showphoto.php/photo/150835


They were great when working, but could be a pain to repair or maintain. I had one shredded on one ship by a lightning strike, but can't a) remember the ship or b) find the damn photo! The whip on top really only provided top loading for 22 MHz. They got porous with age and weathering and the fibre pole lost its resistance lowering loading and output power. They could also build up high resistance in the connecting 'knife' in the bottom box. They were all eventually replaced with STT models, whose type number escapes me now.


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## IanSpiden (Jul 18, 2008)

Yes they were a favourite for P&O Gas tankers , I also had one struck by lightning on the Galconda off Panama around 1979/80 , it totally disintigrated and blew the lead in insulator in half, I had another one struck on the Ryndam in 1999 which had two of them , it just broke and nearly went through the satellite dome so the company took them away as they were redundant by then sadly


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## Mimcoman (May 18, 2008)

Many thanks for all the info, gents - and for the picture, Derek. 

I also have fond memories of replacing the turnbuckles and having to crank the thing up and down a dozen times or more until I was satisfied with the "look" of the wires. I'd better arm muscles than Martina Navratilova by the end. 

Was the STT aerial a fibreglass mast with three whips for top capacity? - or was it six whips: three near the bottom and three further up? If so, Harrison's A-class container vessels were fitted with them, after the first (Astronomer) had left the Gdansk shipyard with a short L-shaped wire aerial which was absolute rubbish on MF. The Adviser came out with the mast aerial, with fellow forum-member Dave Woods as R/O. The Company asked us to do some comparitive tests when we were both mid-atlantic and within MF range. The mast was transparently superior so Astronomer was retro-fitted. 

=====

Hi, Spats. I was never on a ship which was struck by lightning, let alone twice. It must have been an electrifying experience! We always said you had an attractive personality....


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## IanSpiden (Jul 18, 2008)

On the Galconda which was a big gas ship when we were stuck it was about 11 o clock at night , there was just a H*ll of a bang then lots of crashing noises , I went up to the shack and it was full of smoke and ozone so I went next door to the bridge and the 2nd mate was in there white as a sheet dont think the poor guy knew what had happened , interestingly the copper pipe aerial connectors at least the pieces I found had been flattened I can only guess that that the air in the tube had somehow been sucked out and the pressure flattened the tube , the voltage must have been colossal


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## Dave Woods (Apr 9, 2006)

Mimcoman said:


> I wonder if anyone has information on the above transmit mast aerial, which I sailed with on T&J's Strategist and Specialist. It consisted of a white fibreglass support mast with a tubular metal cage at the top and a set of wires from the cage to a metal ring near the base of the mast, all adjusted using turnbuckles. There was a whip mounted on the top of the cage which extended the operating range, but I can't remember if it was for HF or MF.
> 
> I can't find any info on the 'net, but I believe an amateur radio club station at a port in the Netherlands or maybe Denmark uses one.
> 
> ...


My grey cells are working overtime, I believe that the aerial was called -Excuse the Spelling - Beetman and Klapper.(?HUH)


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## King Ratt (Aug 23, 2005)

How about the Deichmann ((??) Klapper antenna which I saw fitted on the British Forth in 1982?. It was a vertical loaded whip which seemed to operate on everything from 5 ton thru to 22 mhz.


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## Mimcoman (May 18, 2008)

On my one trip on the Asiafreighter - mid-70s when she was still gas turbine - the transmit aerials were the Mimco aluminium whips (37 ft if I remember correctly, Ron? ). I heard tell that they were originally fitted near the exhaust vents on the funnel but softened and bent over due to the 800-degree temperature. Does anyone know if this actually happened? The whips were pretty poor on MF; the Crusader had to use the main and emergency aerials in parallel. I did wonder how the installation passed survey.


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## andysk (Jun 16, 2005)

Buoy said:


> .... They were all eventually replaced with STT models, whose type number escapes me now.


Would that be the AS9ST ?

IMRC used them quite extensively in the late 70's - early 80's


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## K urgess (Aug 14, 2006)

Having given the grey matter a good stir since this thread began I couldn't, for the life of me, remember if I ever sailed with such a beast.
I've just found the attached picture proving that I must've sailed with something similair.
Haven't got a clue what type it was but the ship was built by FIAT in Italy and the main Tx was a Kelvin Hughes Zealand S1250 which, if I remember correctly, was quite a meaty beast. That's a helluva lead-in box. The radio room was one deck down from the bridge inboard of my cabin.
I don't remember having any problems but the the furthest we got away from GKL was Lagos so not really tested to it's limits.
It's a good job the VHF had good input damping with that vertical main aerial so close. (EEK)
I think the emergency aerial was still a length of wire.
I always felt better if I could see a good couple of hundred feet of copper wire strung above the deck. [=P]

Kris


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## Buoy (Nov 29, 2006)

AS9ST thats the one! 

I thought all the Big G's had these fitted and not the MAS-20? I stood by *Galconda *building in Emden and I was pretty sure it was the AS9 fitted?? Just found a pic of the naming ceremony in Emden which will post in 'Life on Board'. Although not great you can just see the base of the AS9 at the top right corner. I thought I remembered when I was with PEL that we had to get a replacement AS9 fitted to *Galconda*.

We also used to have huge steel whips on the top of the funnels on the 'Big Ards'. Crusader main tx also. Had a strike in *Ardshiel *off Durban around Xmas one year which just blew out the flexible link and filled the radio office with smoke. Scary enough!


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## Mimcoman (May 18, 2008)

Marconi Sahib said:


> Having given the grey matter a good stir since this thread began I couldn't, for the life of me, remember if I ever sailed with such a beast.
> I've just found the attached picture proving that I must've sailed with something similair.
> Haven't got a clue what type it was but the ship was built by FIAT in Italy and the main Tx was a Kelvin Hughes Zealand S1250 which, if I remember correctly, was quite a meaty beast. That's a helluva lead-in box. The radio room was one deck down from the bridge inboard of my cabin.
> I don't remember having any problems but the the furthest we got away from GKL was Lagos so not really tested to it's limits.
> ...


Nice picture, GTZM-sahib; that's the MAS-20 right enough.

I also wondered about pickup into nearby aerials. On the Strategist, the MAS-20 was on the starboard aft corner of the monkey island, with a receive whip about 10-15 feet away, which I never felt comfortable about, so I moved the whip to the port bridge wing.

(The coax I used was left over from a drum sent out during the maiden voyage so that I could replace the co-ax run from the whip aerial on the forward mast to the radio room. The cable had been stretched either during installation or by ship movement and the inner conductor had broken in many places, making signals intermittent. I ordered a generous amount of coax +10% and Mimco added some more, so there was some 60 metres left over!)


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## K urgess (Aug 14, 2006)

Thanks, Mimcoman (Thumb)
So I can join the MAS-20 club after all. [=P]
Never had to move any whip aerials but had constant trouble with them. The MimCo ones seemed to dislike vibration and salt air. Not very good. Used to see quite a few broken in half in the wind and weather. Especially on VLCCs.

Having used the blender on the grey cells I have a feeling that the Satucket, illustrated above, had a wire aerial running from the crosstrees on the signal mast down to the samson post at the manifold as the emergency. Lowered when the picture was taken because of the derrick being used. I also seem to remember using it for MF working on the main Tx.

One ship we had to go up to Manchester. She was a triple expansion jobbie with a very tall funnel. So, apart from lowering the masts to get under the M6 motorway bridge, the top of the funnel had to be removed as well. I had to take down ALL the aerials because most of them went via the top of the funnel. Lovely job. Said funnel was then left on the wharf at the bottom of the canal. Not much clearance anyway. I seem to remember a crowded bridge as we went under the bridge just in case. About a foot clearance above the mast and below the keel. 
Talk about going aground on an uncharted brick. (==D) 
Since I'd done deep sea and wouldn't be needed for the short trip back to Liverpool I was allowed to pay off in Manchester.
On the way back to Liverpool they managed to forget to pick up the funnel on the way past and had to send it back to Liverpool Docks by road.
I got a frantic phone call asking me where the aerial rigging plan was so they could put it all back together again. The thought hadn't crossed my mind that a 25 year old ship wouldn't have a rigging plan filed.
Never made that mistake again although I couldn't understand what the panic was, once sorted out it was obvious where the aerials went.

I suppose that was the advantage of these whip aerials. The only trouble being to find somewhere to lay 'em down if they had to be removed.


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## Mimcoman (May 18, 2008)

I'd no real problems with receive whips, but it always surprised me how efficient they were, even on MF. The only trouble I experienced was on T&J's Astronomer, when alongside at the Seaforth container terminal in Liverpool. A shoreside container crane wiped out the fibreglass whip on the foremast, so Marconi came down and fitted a metal replacement - I presume because that's what was in stock? - only for the crane to crunch it again. So I was given a spare and asked to fit it after loading and before sailing. Me and Jnr R/O ran a temporary longwire from the matching transformer at the top of the foremast to the railings (much to the mate's annoyance) until we reached the Caribbean. It was easier in the sunshine...

Yes, I remember well having to reconnect waveguides, etc after leaving the Manchester Ship Canal. It always seemed to be snowing or raining or both.


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## Wild_Bob (Sep 5, 2008)

*A similar land based aerial?*

A friend of mine, John K0HGW, and his brother have three of these in service
between them. At one time they owned a total of 12, bought as US Air Force surplus for pennies on the dollar. I think John said the government paid about $26,000 each for them in 1960 dollars. Here is a photo in John's QRZ listing:

http://www.qrz.com/callsign?callsign=k0hgw&sourceid=Mozilla-search

Here is another one installed in Arizona at a former Titan nuclear missile site:

http://gvarc.us/GVARCFrames/Titan/Discone/Discone.htm

They were made under contract to the government by Collins Radio Co.

This is my first posting on this forum. I am a denizen of the high desert in New Mexico and haven't spent much time even near ships, but they've always been a fascination for me. I've known three retired R/O's that decided
to move to New Mexico to retire. I suppose they had their fill of ships and the salt air.

Bob, N5UYA


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## Dave Woods (Apr 9, 2006)

Mimcoman said:


> Many thanks for all the info, gents - and for the picture, Derek.
> 
> I also have fond memories of replacing the turnbuckles and having to crank the thing up and down a dozen times or more until I was satisfied with the "look" of the wires. I'd better arm muscles than Martina Navratilova by the end.
> 
> ...


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## Andy (Jan 25, 2004)

Wild_Bob said:


> Here is another one installed in Arizona at a former Titan nuclear missile site:
> 
> http://gvarc.us/GVARCFrames/Titan/Discone/Discone.htm


I just love the fact that you can drive up, plug-in and use it, terrific!! 
Pity Droitwich don't have such a facility, I'm sure they've got something spare that would be ok for top band


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## Mimcoman (May 18, 2008)

Dave Woods said:


> Mimcoman said:
> 
> 
> > Many thanks for all the info, gents - and for the picture, Derek.
> ...


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## Mimcoman (May 18, 2008)

HI, Wild Bob, and greetings from Northeast Scotland : 

Thanks for taking the time to respond, your input's much appreciated.

The UK MF coast radio stations used conical monopoles a great deal (although not exclusively). At Stonehaven Radio/GND, we eventually had four of them, about 165 feet in height and operating over 1.6-4MHz. Because they were by definition a wideband aerial, we ran up to four 1kW pep transmitters into each aerial through a combiner unit containing L/C acceptor and rejector circuits.

At Aberdeen Coastguard, we still use one, manufactured by an American company: 

http://www.antennaproducts.com/omnilpaindex.htm

The one we use is the CMV-602 (fed by a Skanti 8750S transceiver, which because of its age is due for replacement very shortly).

Best regards
Bill


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## Finbar O'Connor (Sep 26, 2008)

Hello Bill,

You refer to the CMV-602 as used by Aberdeen CoastGuard. Do you
know if the tower section is grounded and the antenna is fed at the
lower skirt wire, Unipole fashion ??.

We use 150 foot towers at Malin Head Coast Guard Radio EJM

Aberdeen Coast Guard's signal is probably the strongest of the UK
signal's on 2182 khz. Many of the others are weak and lack punch.
Are they using simple whips and lower power perhaps ?

We run 1 kw using 4 Rohde and Schwarz transmitters, but 
also have two 750 watt Skanti's at Malin Head, plus 2 more Skanti's at
our remote MF/HF site at Belmullet, in County Mayo.

Best regards
Finbar O'Connor
Malin Head Radio EJM


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## Mimcoman (May 18, 2008)

Hello, Finbar:

Nice to hear from you again, we spoke directly some time ago re morse recordings.

I'll have to look at the aerial again, but unfortunately the transmit site is unmanned and some distance away. I think the support mast is a part of the radiating element(s?), as at GND. 

The ones at GND had a large insulated base support on which the mast could move (slightly!) by means of a stainless steel ball, and the feed was to the metal ring to which the cage wires were attached. The earthing mat for the aerial was attached to the structure below the insulating base. On one of the masts, we had a matching problem at one of the four frequencies fed to the aerial, so the BT aerial consultant moved the aerial feed impedance by running a length of wire from the point on each wire where the guys which shape the aerial are attached back to the mast itself ( so the mast was part of the radiating element). 

The majority of the UK CG sites use a vertical whip (mostly Bantex, but there are others) or a long-wire, usually T- or L-shaped. The Skantis are 250W or 750W transceivers, the higher powers being at locations which have greater sea areas to cover. Aberdeen is the only one with the conical monopole, and other reports have also mentioned the signal strength difference. I'm involved (on the periphery) in setting up HM CG's Business Requirement for a forthcoming update of its MF/HF equipment and brought the Irish coast radio (sorry - Irish Coastguard Radio) stations' equipment into the picture as a reference. Your signal is also well received up here and I try to emphasise to them that its quality is due in large part to your aerial installations (as listed on your EJM website).

I envy you your R&S equipment.

Best rgds
Bill


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## Finbar O'Connor (Sep 26, 2008)

Hello Bill,

Thanks for the description of both the BT system and current CG antennas.

Yes, I agree, our twin 150 foot towers really do the business. In the last
few weeks we had new wooden fencing erected around the feedpoints of
our towers and discovered that the main 4 inch copper strip to the earth
system had become dislodged. The value of being all co-sited was a quick
repair which entailed me heading home a few miles, picking up my heavy
soldering gas bottle, wire brushes and kit and returning to remake the
soldered connection. The R and S equipment supplied also included 4
auto ATU's ( two spare) which means we can tune our towers to any
frequency between 1.6 mhz and 30 mhz, very handy when we work
long range to our helicopters on 3023 khz and 5680 khz.
The other tower earth system was checked, following our discovery of
the dislodged earth connection on our East mast. The West mast was
fine, no problem.

Our radial system is the classic type, however some are just a little shorter
than we would like due to the closeness to the boundary fence, but are
still 100 feet long at their shortest.
All services at both Malin Head and Valentia ( except for VHF) are 
co-sited, except that the main receive antenna is about 1 mile away and
fed by open wire feeder to within 200 metres of the station and then 
underground by co-ax.
The Navtex transmitter ATU and feedthrough insulator to the drop 
wire from the "Tee" antenna is only about 5 feet away from all our
PC servers, PABX and data lines. The only thing that gives grief is a 
modem ( old one) for a stand alone PC not connected to the main PC
system which latches up once the Navtex transmitter keys up and
occasionally does the same with our 2182 and 1677 khz transmissions.

Best regards
Finbar Malin Head Coast Guard Radio EJM


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## Mimcoman (May 18, 2008)

Thanks, Finbar: 

Coincidentally, some persons who were recently in temporay residence near the remote site removed the copper strip which ran from the base of the vhf aerials' support mast back to the equipment hall technical earth. Fortunately (or perhaps not), the vhf support mast is just that. They overlooked the strip from the MF/HF aerial.

Diddley-da-di-dah,
Bill


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## Finbar O'Connor (Sep 26, 2008)

Bill,
I posted you a long and detailed reply regarding our MF equipment at
Malin Head, last week.

I am surprised to find it did not get on to this forum. Not sure where it
disappeared to.

A real pity, I can only remember half of what I sent in the original
posting.

Best regards
Finbar Malin Head Radio EJM


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## Finbar O'Connor (Sep 26, 2008)

Hello Bill,

You get that type everywhere. I hope you get the upgrade your looking for
on MF/HF.

A couple of spare , redundant Skanti's would come in nice and handy.

Best regards
Finbar EJM


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## Mimcoman (May 18, 2008)

Hello again, Finbar:

There's a dearth of Skanti spares, or so I'm told, which is part of the reason why they're being replaced. (Cannibalisation is in force, as is/was hunting on ebay by the maintenance company.) I don't know what will happen to the redundant gear, but it's unlikely to be made available to anyone, for health and safety reasons. Anyway, they're pretty basic units - ssb filter only; no CW, AGC on/off only; etc.

Rgds/Bill


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## Finbar O'Connor (Sep 26, 2008)

Hello Bill,

As a matter of interest, are there any plans to close down any of
the MF UK coastguard sites, ie the low power/whip aerial types and
perhaps upgrade the remaining ones. Some of those who do tests at
night are usually quite weak and rarely seem to get any calls, except
the local lifeboat, when out on exercise.

I suppose you have noticed that Clyde are using 1883 khz, the old
GPK working frequency. Not the same without Graham Mercer
booming out on the mic.

By the way, our remote MF/HF site at Belmullet , County Mayo, 
which uses a pair of 750 watt Skanti's has an amazing receive
capability. Quiet location surrounded by bog and sheep nibbling
on the sparse grass and a gale blowing most of the time. I
spent a week there when we initially installed the gear. Winter
in Belmullet is not for the faint hearted.

Best regards
Finbar EJM


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## Mimcoman (May 18, 2008)

Finbar:

Can't really comment on what's going to happen at the UK CG sites, but in general the whole system is to be upgraded and is out to tender. It would seem that half the MCA's (Maritime & Coastguard Agency) Project Team are ex-R/Os, so at least they are receptive to the need for good aerials, designed for for land-based use. 

The Skanti does seem to have a good receiver; it's just that our ones are very basic..... 

Rgds/Bill


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## Finbar O'Connor (Sep 26, 2008)

Hello Bill,

Will await developments in MF for our UK CG friends. I can understand
your position.
We expect to have our Skanti changed out in 2009. The R and S 
transceivers cost a fortune, 8 sets in total, 4 for EJM and 4 for EJK.
They should last a good while. We also had our Navtex transmitters
changed 2 years ago and we get an easy 1 kw output. 
Next in the pipeline is a whole new command and control equipment
fitout, costing 2.5 Million Euro for all three station in the network,
ie, Dublin, Malin Head and Valentia.
Regards
Finbar EJM


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## Troppo (Feb 18, 2010)

andysk said:


> Would that be the AS9ST ?
> 
> IMRC used them quite extensively in the late 70's - early 80's


Yep - that's them. I sailed with one on the P and O box boat Ariake/GWED - we had STR1600 main tx'ers.

I still have the "P and O Radio Service" date stamp from good old GWED.


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