Jump to content
Funksammler

Festungsantenne

Recommended Posts

Funksammler
Moderator

The "Festungsantenna neuer Art" was a special antenna system for use in concrete bunkers. The iron rebars and roof beams turned any reenforced bunker into a Faraday cage, so no radio signals can come in or out a bunker without special antenna arrangements. The "Festungsantenne" consists of the antenna itself, which could be pushed through a tube in the roof of the bunker from the antenna niche inside. The antenna in the niche was connected to radio in the interior of the bunker by a coax cable between and two connection boxes:

1051527360_Festungsantenneoverview.thumb.jpg.5c56e23338fc6d2f9906cd94db85613c.jpg

The main components of the system include the antenna base on which three antenna rods were placed, wooden poles to push the antenna up through the roof, a connection box placed in the antenna niche to connect the HF cable to the antenna (FAD: Funk Außenanschluß Dose), interconnecting coax cable, radio connection box (FID: Funk Innenanschluß Dose). A support for the antenna rods and a text plate complete the installation:

DSC01079.thumb.JPG.194222994dea2748ec75008d6a0203bc.JPGDSC01080.thumb.JPG.6f4fec5fefabc3855119f6efa63cb58b.JPG

The antenna base itself sits on the guide. The base and guide have small rollers which allows the antenna to move smoothly through the tube in the roof. The wheels on the antenna base also serve to keep the antenna folded while inside the tube, when the top of the antenna base is pushed out of the top of the tube, the antenna rods will spread out automatically:DSC01081.thumb.JPG.a85941e909ac22b1e032dbb0ce626f41.JPG

A close up of the spreading mechanism of the antenna base: 

DSC01082.thumb.JPG.9253d4b9853ff1722c5642f5c1936214.JPG

The three two-piece whip antennas (which I am missing unfortunately) allowed for a short or a long antenna, dependent on the frequency of the radio used (photo from an old Ebay auction):

fat_4.thumb.JPG.df8850b1e872bd26daeb29565b182778.JPG

The antenna base was supported by wooden rods. Either telephone wire poles (Baustangen) or lineman's poles (Drahtgabelstangen) were used for this purpose, I am showing two "Baustangen" with the antenna:

DSC01083.thumb.JPG.5ec4bd1fe70ce90ba38c1e00b986c74d.JPG

The antenna was pushed up using the telephone pole after which a second pole was connected underneath. The bottom pole was rested in a support at the base of the antenna niche (the "Antennenstütze"): DSC01089.thumb.JPG.6c2dec39df1a3954a46cd810c97e531c.JPG

When the antenna was not in use, the antenna poles were stored in one side of the antenna niche, indicated by an instruction plate: 

DSC01090.thumb.JPG.daedfaa0ab8c1e5f0c1a5d6adc26fd8d.JPG

A long flexible coax cable is attached to the antenna base, ending in a bakelite coaxial connector:

DSC01084.thumb.JPG.3e35a01dac49df3fd045bd34ce07f164.JPG

The connector connects into the Außenanschlußdose mounted in the antenna niche: 

DSC01085.thumb.JPG.f11776169ab3f9141ff830a5e3673b12.JPG

DSC01086.thumb.JPG.3e5b640b34a991628d55a49682e0cf0f.JPG

An armoured coaxial cable runs from the Außenanschlußdose to the Innenanschlußdose inside the interior of the bunker. Only specific lengths of cables could be used (15, 22,5 or 30 Meters). That is why you sometimes see pictures of a cable running in zig-zags along the interior wall of a bunker, this was to deal with any overlength of the antenna cable. These precise lengths were needed to ensure that a standing wave would occur in the antenna feed when using the Torn.Fu.d2. This was not so much an issue for the higher VHF frequency Feldfunksprechers but it did require another trick when lower frequency HF sets were used. The cable led to the Innenanschlußdose inside the bunker to which the actual radio was connected:

DSC01091.thumb.JPG.90113141ddd500af86dad4b54753e4a5.JPG

The Innenanschlußdose is a heavy cast iron box in which two different contact units could be fitted. The contact units connect to coaxial cable via the connectors in the top section of the box:

 DSC01093.thumb.JPG.fd5ff1d87c946b6ed1b93b591e737c7f.JPG

The round "carousel" under the contact plate allows a pin to be fitted in three different positions dependent on the length of the coax cable (15, 22,5 or 30 meters).

The two different inserts are a simple connection plate for VHF radios (Torn.Fu.d2, Feldfunksprechers, Festungsnotsender etc.) and a more complex antenna tuner for shortwave radios (Torn.Fu.b1 or Torn.Fu.f):

DSC01094.thumb.JPG.7a2c27c949dc8971c095fa7df0707fab.JPG

The backside shows the antenna contacts which engage with the contacts in the FID:

DSC01095.thumb.JPG.322756532a84a4637a72a83ccd57dc0f.JPG

Now the reason for the pin on the "carousel" in the FID becomes apparent, as the shortwave tuning unit also has to be set to the correct coax cable length. In this case it has been set to "1" (for a 15 meter coax cable length), only one guide hole is open corresponding to the pin in the FID. If the tuning unit is not set correctly, it will not fit into the box.

Here is the FID with the VHF and shortwave unit fitted respectively:

DSC01096.thumb.JPG.935241a4b9bdb90247f005432247b571.JPG

DSC01092.thumb.JPG.4cccd3de9959d8e3ed223b5fa66389fc.JPG

The unit not in use was stored into the storage box which was kept in a cupboard inside the bunker (the "Funkgeräteschrank"). This also stored the radio itself when not in use and contained manuals, spare batteries, connection cables etc. A shield on the FID points the user towards the manual:

DSC01099.thumb.JPG.212ac79769c12e364fd4c4de99d240fc.JPG

So when the Festungsantenne was used with a VHF radio, no additional antenna tuning was required, but when using the HF Torn.Fu.b1 or Torn.Fu.f, the antenna had to be tuned to the specific frequency used by turning the tuning control for maximum antenna current on the instrument. Even with the lid of the FID closed, the antenna current instrument could be observed through a window in the lid.

Finally, some more constructional details of the complete antenna showing the complete path from the radio to the antenna:

1562554947_File001420small.thumb.jpg.65d0491fcd6d7114fddaeb229902020b.jpg

regards,

Funksammler

 

Share this post


Link to post
Share on other sites
kriegsfunker

Spectacular.   Your setup is more complete than Arthur Bower's.   How did you find these crazy rare pieces?

Share this post


Link to post
Share on other sites
val
Moderator

Just outstanding!!!

Share this post


Link to post
Share on other sites
Funksammler
Moderator

Arthur borrowed the FID from a Dutch bunker collector to take the pictures, it does not reside in his collection. I have been collecting and restoring the antenna parts over many years, it is probably one of the most complete examples remaining in the world today.  I am planning to build an antenna niche/radio position of the correct dimensions to demo the complete system, still need to go and measure it up in a local bunker. The challenge will be to find space for it in my overcrowded room. I guess the missing whip antenna will not such a miss, as it would be impossible to display indoors anyway due to the height.....

regards,

Funksammler

Share this post


Link to post
Share on other sites
tornfuté

Yes fantastic , well illustrated and described . I just wonder about this 

the antenna well is protected outside the bunker by a plate , otherwise

sand or rain will enter the well . Is it possible to remove  it with the  telephones

poles?  When you push the antenna from’ inside , i guess there is a stop device  otherwise the antenna will jump out of the well.

 

Share this post


Link to post
Share on other sites
Funksammler
Moderator
22 minutes ago, tornfuté said:

Yes fantastic , well illustrated and described . I just wonder about this 

the antenna well is protected outside the bunker by a plate , otherwise

sand or rain will enter the well . Is it possible to remove  it with the  telephones

poles?  When you push the antenna from’ inside , i guess there is a stop device  otherwise the antenna will jump out of the well.

 

You can see some Festungsantenne hardware on this website:

http://www.atlantikwall.info/aw/bilderologie/antennen.htm

It shows the heavy covers still in place on one of the photographs. They are fitted over the end of the tube and turned a quarter of a turn to lock them in place. So it was essential to remove the covers before anticipated use, I guess somebody was tasked to remove the covers when the alarm was given. 

From the construction drawings, there seems to be a ridge near the top on the inside of the tube. When the antenna is rolled through the tube, this ridge must give a good indication that the antenna is near the end of the tube when the wheels run through it; if the ridge actually stops the antenna from going any further, I don't know. The length of the poles and the position of the "Antennestütze" was set so that the top of the antenna base was just outside the tube.

If the whip antenna's got shot off, somebody either had the break cover and replace them on top of the bunker, or had to retract the antenna and push the repaired assembly back up... Note that the antenna niche was actually in the entrance "hallway" of the bunker, so not the most secure area. If the bunker was under close attack form the rear, operating the Festungsantenne must have been a pretty hazardous job. 

regards,

Funksammler

Share this post


Link to post
Share on other sites
tornfuté

we have to identify if the

antenna well is in cement 

or with a steel tube 

a good check will be to 

try an antenna  in a genuie

bunker  , of course not all are

fitted with radio but some

exist . i must have somewhere a pix showing 

a rotating cover plate , there 

is also one for the optic well.If the telephone line

is cutted and  whip antenna

broken there is also an emergency antenna  

and in some case they 

make home made antennas

it's a good subject that is 

not widely described .

 

Share this post


Link to post
Share on other sites
tornfuté

some bunkers pictures seen on eBay or web.

from pix number 1 we can say the top of the well is made of steel

3518.jpg

bunker_antenna_mount_interior.jpg

fat_1.jpg

fat_2.jpg

fat_3.jpg

fat_4.jpg

fat_5.jpg

fat_6.jpg

fat_7.jpg

r618h.jpg

sombre-ov.jpg

Share this post


Link to post
Share on other sites
val
Moderator

Share this post


Link to post
Share on other sites
tornfuté

Val good description but picture is a 3d picture not real one .

FS , is there a difference between telephone poles and festung poles?

on the picture we see a telephone pole and an other one different 

a sharp one that goes in a metal  support rest 

i think it’s difficult to push with the telephone pole  sharp side

Share this post


Link to post
Share on other sites
Funksammler
Moderator

Even though the manual mentions "Drahtgabelstange", the standard 3 piece linesman poles are too thin while the two piece linesman pole is too large. The "Bausstangen", even though they are pointy, fit snugly and securely into the antenna support.  My pictures shows one of the "Baustangen" with its point inserted into the base. Even though my instruction plate was in very poor condition and was poorly overpainted , the original text clearly mentioned "Baustange". (I am not sure why they used "Stange" instead of the plural "Stangen", must be old German...). There is a hole in the side of the antenna base for a spring fastener, but it does not fit any of the poles I have. 

I suspect there must have been a slightly different versions of the antenna guide suitable for the 3-piece linesman pole, the manual mentions one with a bayonet-lock for the 3-piece linesman poles which is clearly different from the one I have.

Perhaps the 3-piece "Drahtgabelstangen" were no longer issued later in the war or, since the "Baustangen" exist in different lengths (the longer end pieces and the shorter middle pieces), the "Baustangen" offered a more flexible system to achieve different heights required...

regards,

Funksammler

Share this post


Link to post
Share on other sites
Funksammler
Moderator
6 hours ago, tornfuté said:

some bunkers pictures seen on eBay or web.

from pix number 1 we can say the top of the well is made of steel

3518.jpg

It think this is probably not Festungsantenna, I suspect this is more like a periscope shaft. It looks like it had a lid fitted to an axle on the side, which could be rotated (and locked?) from the inside. 

Share this post


Link to post
Share on other sites
Funksammler
Moderator

Some more reading: D1790-1 "Merkblatt für den Aufbau von Truppenfunkgerät und Behelfsantennen in ständigen Anlagen der Landesbefestigung". This describes the different setups in some detail:

http://www.cdvandt.org/D-1790-1.pdf

regards,

Funksammler

Share this post


Link to post
Share on other sites
val
Moderator

The image Pierre was posting is originally taken from here:

http://www.pizzatravel.com.ua/eng/ukraine/5/fortified_bunkers_of_kiev_south

Search there image "Holes in the roof of the bunker #179 for antenna and periscope ©Yuriy Buriak"

So this is not even a German bunker.

 

Share this post


Link to post
Share on other sites
Desert Rat

Hello to you All,

Superb images and a great text regarding the German bunkers and what was involved in the communications side. It's very interesting and something I knew nothing about until now!

Many Thanks to......Desert Rat

Share this post


Link to post
Share on other sites
val
Moderator

Remembered i have those links too...

http://le-pingouin-62.chez-alice.fr/r504-radio.htm

http://www.atlantikwall-research-norway.de/Bunker_electric_equipment.html

@Funksammler - does the antenna head opens up? It would be interesting the see it's

inside.

Share this post


Link to post
Share on other sites
Desert Rat

Many Thanks Val,

I wish I was intelligent as you and Funks etc etc....I used to love the all the comms etc from ww2.

Best to you & Thanks....Desert Rat/ Ian

Share this post


Link to post
Share on other sites
Funksammler
Moderator
10 hours ago, val said:

 

@Funksammler - does the antenna head opens up? It would be interesting the see it's

inside.

I am not going to open up my antenna head! Fortunately I have a detailed construction drawing: 

624849000_Antennatopsketch.thumb.jpg.55d660fcee452ad493d3bd453ee62545.jpg

As you can see the spreaders are pushed to the outside by a leaf spring connected to the base. 

regards,

Funksammler

Share this post


Link to post
Share on other sites
Funksammler
Moderator
15 hours ago, Funksammler said:

Even though the manual mentions "Drahtgabelstange", the standard 3 piece linesman poles are too thin while the two piece linesman pole is too large. The "Bausstangen", even though they are pointy, fit snugly and securely into the antenna support.  My pictures shows one of the "Baustangen" with its point inserted into the base. Even though my instruction plate was in very poor condition and was poorly overpainted , the original text clearly mentioned "Baustange". (I am not sure why they used "Stange" instead of the plural "Stangen", must be old German...). There is a hole in the side of the antenna base for a spring fastener, but it does not fit any of the poles I have. 

I suspect there must have been a slightly different versions of the antenna guide suitable for the 3-piece linesman pole, the manual mentions one with a bayonet-lock for the 3-piece linesman poles which is clearly different from the one I have.

Perhaps the 3-piece "Drahtgabelstangen" were no longer issued later in the war or, since the "Baustangen" exist in different lengths (the longer end pieces and the shorter middle pieces), the "Baustangen" offered a more flexible system to achieve different heights required...

regards,

Funksammler

The sketch of the Antenne base (similar to the one in D1790-1) is worth a second look:

1419654919_Antennaguide.jpg.0f5e16a1fa320e08979a9a3ea16fc1f8.jpg

Looking at this, I am starting to realise that the "Drahtgabelzwischenteil" is actually an adaptor that connects to the bottom of the "Führungsschlitten" (the line pointing to it should have been drawn slightly higher, it is actually pointing at the top of linesman pole). It is clearly drawn protruding further down from the bottom of the antenna guide than on my actual example:

DSC03821.thumb.jpg.578079aa27c0bb656240307ef59b28e4.jpg

 This protrusion can also be recognised on the overview sketch:

1126318174_Festungsantenneoverview.thumb.jpg.9d29c93d3b6341769e34f7decea29c23.jpg

This is now starting to make sense: without adaptor the guide is suitable for use with the "Baustangen", with adaptor it works with the 3-piece "Drahtgabelstangen"...

Now the hunt is on for any evidence of a surviving "Drahtgabelzwischenteil"!

regards,

Funksammler

Share this post


Link to post
Share on other sites
tornfuté

Val you are right , i register the picture on a bunkerforum but had thought

it was german , in fact it’s russian  , i make mistake and i learn everyday.

when reading about bunker R618 , where they are lot of antennas  i read that

the festungantenna is stowed in a wooden box , and that for emergency

use somebody has to go on toproof for removing  antenna protection

like FS said in case of attack it’s not the best job .

They are still shadows in this subject but it become more easy to understand

how the antenna works .

i have seen a picture of a steel cabinet , near antenna niche , i guess it’s

used for stowage , but which one? Antenna, cables , radio like lo1uk35?

FS i had seen a special bag where there were 4 rods , made in bakelite

around 30 mm diameter, with bayonet lug , it was for owner and me 

unknow , may be it was bunkerstange? No picture as it was long time ago

Share this post


Link to post
Share on other sites
val
Moderator
1 hour ago, Funksammler said:

Now the hunt is on for any evidence of a surviving "Drahtgabelzwischenteil"!

From the sketch i see that the antenna mount has down there some tube with

bayonet connection? @Funksammler - can you show your antenna mount end

more closely (without that telephone pole) - your ends with rollers and their connection ring.

Share this post


Link to post
Share on other sites
val
Moderator

I haven't gone through the whole following thread, but there's some bunker

antenna setup related photos.

https://forum.axishistory.com/viewtopic.php?f=70&t=60961

For example page 16:

https://forum.axishistory.com/viewtopic.php?f=70&t=60961&start=225

Add those images to this thread, @Funksammler

Share this post


Link to post
Share on other sites
ChrisMAg2
(edited)
15 hours ago, Funksammler said:

The sketch of the Antenne base (similar to the one in D1790-1) is worth a second look:

1419654919_Antennaguide.jpg.0f5e16a1fa320e08979a9a3ea16fc1f8.jpg

Looking at this, I am starting to realise that the "Drahtgabelzwischenteil" is actually an adaptor that connects to the bottom of the "Führungsschlitten" (the line pointing to it should have been drawn slightly higher, it is actually pointing at the top of linesman pole). It is clearly drawn protruding further down from the bottom of the antenna guide than on my actual example:

DSC03821.thumb.jpg.578079aa27c0bb656240307ef59b28e4.jpg

 This protrusion can also be recognised on the overview sketch:

1126318174_Festungsantenneoverview.thumb.jpg.9d29c93d3b6341769e34f7decea29c23.jpg

This is now starting to make sense: without adaptor the guide is suitable for use with the "Baustangen", with adaptor it works with the 3-piece "Drahtgabelstangen"...

Now the hunt is on for any evidence of a surviving "Drahtgabelzwischenteil"!

regards,

Funksammler

@Funksammler,

in case you have not noticed yet, Val's last post with the links has the reason/ explanation why your little sign seems to have a grammer anomaly:

Your repainting/ reconstruction of the sign is lacking the "dot" after the number/ digit "2". The dot indicates the numerical order (as in the second Baustange) and not the amount (as in how many in total -> no dot there).

Regards,

Christian M. Aguilar

Edited by ChrisMAg2
edit typos

Share this post


Link to post
Share on other sites
ChrisMAg2
(edited)
On 05/03/2019 at 02:20, Funksammler said:

Even though the manual mentions "Drahtgabelstange", the standard 3 piece linesman poles are too thin while the two piece linesman pole is too large. The "Bausstangen", even though they are pointy, fit snugly and securely into the antenna support.  My pictures shows one of the "Baustangen" with its point inserted into the base. Even though my instruction plate was in very poor condition and was poorly overpainted , the original text clearly mentioned "Baustange". (I am not sure why they used "Stange" instead of the plural "Stangen", must be old German...). There is a hole in the side of the antenna base for a spring fastener, but it does not fit any of the poles I have. 

...

I am very sorry,  but my comment earlier is actualy referrring to this quote. So again:

Funksammler,

in case you have not noticed yet, Val's last post with the links has the reason/ explanation why your little sign seems to have a grammer anomaly:

Your repainting/ reconstruction of the sign is lacking a "dot" after the number/ digit "2". The dot indicates the numerical order (as in the second Baustange) and not the amount (as in how many in total -> no dot there).

Regards, 

Christian M. Aguilar 

Edited by ChrisMAg2

Share this post


Link to post
Share on other sites
Funksammler
Moderator
7 hours ago, ChrisMAg2 said:

I am very sorry,  but my comment earlier is actualy referrring to this quote. So again:

Funksammler,

in case you have not noticed yet, Val's last post with the links has the reason/ explanation why your little sign seems to have a grammer anomaly:

Your repainting/ reconstruction of the sign is lacking a "dot" after the number/ digit "2". The dot indicates the numerical order (as in the second Baustange) and not the amount (as in how many in total -> no dot there).

Regards, 

Christian M. Aguilar 

That makes sense, thanks for pointing that out.

Also interesting on the drawing is the comment: "Kugelschnäpper der obere Baustange muß in die Bohrung des Führungstuckes eingerastet sein", while the instruction plate mentions "Festungsantennestange". There are a hole and a slot in the bottom of the guide to for a locking mechanism. Standard "Baustangen" lack this mechanism, so the drawing seems to suggest that there was a type of "Baustange" with a locking mechanism called the "Festungsantennestange". So now we have three different types of poles mentioned for use with the Festungsantenne: Drahtgabelstangen (with a "Zwischenstück"), Baustangen and Festungsantennestangen...

regards,

Funksammler

DSC01117.JPG

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...