A replacement radio vehicle (Ersatz-Funkwagen) or a replacement motor vehicle (Ersatz-Kraftfahrzeug) was a replacement vehicle assigned to the troop for missing special vehicles.
Many people always think that the Wehrmacht was very well equipped with vehicles in the early war years. However, this is only true to a very limited extent, since the majority of the Wehrmacht actually moved ahead with horses during the Polish and French campaigns.
Although more and more vehicles were made available to the Wehrmacht, far more vehicles were needed for the rapid operations.
As it had always been a "tradition" in the German military, they knew how to help each other.

The Citroen U23 used by the german Wehrmacht


So-called replacement vehicles were simply made available for missing vehicles. These were either civilian vehicles or captured vehicles which were then converted by the soldiers themselves into almost fully-fledged special vehicles.
It should be noted that it is really interesting how many foreign car brands can be found on original photographs of the Wehrmacht. Renault, Citroen, Rover, DAF, Dodge, Ford,... The list of foreign vehicles used is very long.

The motor vehicles could either be taken over 1:1, or they had to be provisionally prepared for special tasks.

The project "Wehrmacht Ersatz-Funkkraftwagen (Replacement-radio-truck) - How a Citroen U23 becomes an Wehrmacht Kfz.61" is about exactly such a replacement vehicle.
Here a light Citroen U23 truck was assigned to the unit of my grandfather. This had to be prepared then makeshift from a commercial motor vehicle to a so-called replacement radio motor vehicle.
The leaflet D963/8 "Merkblatt für die behelfsmäßige Herrichtung von handelsüblichen Kraftwagen als Ersatz-Funkwagen" gives exact information about what had to be paid attention to.

Merkblatt für die behelfsmäßige Herrichtung von handelsüblichen Kraftwagen als Ersatz-Funkwagen


According to these instructions, only the following radio vehicles were permitted to be used as replacement radio vehicles:

  • Funkkraftwagen Kfz.61
  • Funkkraftwagen Kfz.17
  • Funkkraftwagen Kfz.17/1
  • Funkkraftwagen Kfz.2

Actually there are no exact building regulations! For all soldiers, the leaflet was regarded as a "comprehensive overview of tried and tested patterns as an indication of possible remedies".
So instead of building regulations, the Wehrmacht had guidelines on how to set up and equip replacement radio vehicles!
"It is left to the skill of the troops to carry out the fitting-out work on the basis of these guidelines, but experience has shown that a general regulation is highly recommended at least in the association of an AK (army corps). The intelligence departments (Nachrichtenabteilungen) are to be consulted for cooperation with the troop intelligence units (Truppennachrichtenverbänden)."
The difference between the Nachrichtenabteilungen and the Truppennachrichtenverbänden is shown in this article (at the moment only available in german):

Aufteilung der Truppennachrichtendienste in der Wehrmacht


In summary, there are no rules, only guidelines. A free hand for the soldiers but under the supervision of the intelligence departments. Within an army corps, however, the replacement radio vehicles should have a similar structure.
This is surprisingly open for a military instruction and explains why no defined instruction but only a leaflet was issued.

Now, however, there are different radio teams in signal units which were each transported with differently equipped radio cars.
Most of the communication units were so-called motorized units.
To be part of a motor unit (mot.-Einheit) by definition, a vehicle had to be available to transport the soldier. Many may also know the term "fast troops", which results from this.
By the allocation of the replacement vehicles exactly this principle was ensured as far as possible.
And exactly about this there are now more exact guidelines in the leaflet:

  1. The scope and type of the telecommunications equipment form the basis for a technically usable facility.
  2. It must be possible to transport the crew to which the "Funktrupp" is entitled according to the number of crew members.
  3. The weight of the complete equipment and crew must not exceed the load capacity of the vehicle.
  4. As a rule, the required power sources of the radio equipment shall be provided by making use of the power source system of the motor vehicle. Only if the replacement position does not permit the allocation of such devices to motor vehicles shall other vehicle types be used, but in accordance with the principles described under 1) and 3), because in this case a battery with sufficient storage capacity corresponding to the radio set shall be additionally provided. The provision of the collectors required for this purpose shall be specially arranged. It must also not be overlooked that such a power source supply of the makeshift radio teams requires a regulated supply of collectors for use.


The following (very interesting) table contains a compilation of the "Funktrupps" with the radio vehicles to be replaced, the weight data for the telecommunications loading and crew, as well as power requirement data for the radios:

List of the Wehrmacht Funktrupps


For the project "Wehrmacht Ersatz-Funkkraftwagen (Replacement-radio-truck) - How a Citroen U23 becomes an Wehrmacht Kfz.61" the consecutive number 2 is important:
The radio crew (mot.) is the m.Fu.Tr.b (medium radio crew b).
The radio, i.e. the transmitter, is a 100-watt transmitter (100-Watt Sender).
The Kfz.15 and Kfz.17 are registered as vehicles to be replaced. But it is a Kfz.61. More about this further down in the text.
The weight of the telecommunications load is approx. 495 kg.
For the weight of the crew (including full equipment) 800 kg were estimated, thus 100 kg per soldier.
The power consumption at 12V is 40 - 45 Ampere.


The Funkkraftwagen Kfz.61

But how do I come up with a Kfz.61 for the project?

Wehrmacht Kfz.61


As already stated in the project description, the size of the replacement radio car, the equipment to be seen on the pictures and also the information from the photo album indicates this. In fact you can see my grandfather on many of the pictures in a Kfz.61. At least until 1941. So the assumption is obvious that the Kfz.61 was destroyed or heavily damaged and the unit of my grandfather was equipped with the replacement radio car Citroen U23, or was assigned a Citroen U23 and carried out the box construction himself.

The Kfz.61 is actually dealt with in a separate part of the leaflet. The equipment of a Kfz.61 includes so much that this would simply be too much for this leaflet. Therefore, it does not appear in the above list, but has a separate part in the leaflet.

Structure of the devices in a german Kfz.61Structure of the devices in a german Kfz.61


The radio motor vehicle Kfz.61 was registered within the Wehrmacht as a "light radio motor vehicle (Funkkraftwagen)". The "Heavy Funkkraftwagen" was e.g. the Kfz.72.
Within the D963/8 the Kfz.61 is actually similarly led as the Kfz.17. At least if it concerns the example for a spare radio car.
The only difference: The Kfz.61 served primarily as an example for the makeshift installation of trucks with a closed body of more than 1 t payload.
Kfz.17 served as an example for trucks with open and closed bodies of more than 1 t payload.
The data sheet for Kfz.17/1 goes even further. This serves as an example for trucks with less than 1 t payload or more than 1 t payload.

Wehrmacht Kfz.61 storage
The replacement radio car Citroen U23 had to fully replace the Kfz.61.
This also included the storage space for the equipment of the radio crew.


A replacement radio car for the Kfz.61 had to be set up according to the D963/8 for sending in motion. This means that the radio operation in the provisionally prepared vehicle had to function while the vehicle was in motion.
The basis for this, of course, is a permanently installed roof antenna, which can be easily recognised from the Citroen U23.

Roof antenna of the Citroen U23


The height of the roof antenna naturally had a great influence on the transmission power. Therefore there were precise instructions:

  • It had to be at least 30cm above the roof.
  • It must not be above 2.95m above the ground.

The 2.95m are calculated from the fact that it was essential for the Wehrmacht that the vehicles could be transported by rail. The vehicles were therefore allowed to have a maximum of 2.95m high and a maximum of 3m wide.

Dimensions of the german Opel Blitz radio car


By the way: If it was not otherwise possible and the antenna went beyond the maximum dimension, the antenna had to be provided as a removable antenna.

An important question which is still in the room is whether the box structure of the Citroen U23 was made of sheet metal. Sheet metal was not actually used for radio cars. The bodies were usually made of wood or cardboard which had the reason that a sheet metal body has a negative influence on the antenna performance.

In the D963/8 it says to this:
"Also the use of trucks with closed sheet metal construction must remain limited only to urgent exceptional cases, if not at least the roof is made of wood. (e.g. Opel truck with closed body on 3 t chassis)".

In all factual terms: It is rather unlikely that the box construction of the Citroen U23 is a pure sheet metal construction, but still not impossible.

These are first of all all generally summarized information about the replacement radio cars in relation to the Citroen U23.
In the following parts I will deal in more detail with the antenna construction and the installation in replacement radio cars - especially with the installation of the Citroen U23 replacement radio car.

The next part will deal specifically with the "set of installation equipment for the preparation of commercial trucks with a payload of 1t and more" (Satz Einbaugerät für die Herrichtung handelsüblicher Lastkraftwagen von 1t Nutzlast und mehr)

So it remains exciting!

This will probably be the biggest project I'll ever tackle.
But in 2019, after careful consideration, I have finally decided to start this project!
All progress on this project will be published here on www.nachrichtentruppe.de in the form of a blog.


A puzzle that starts at "0"

What do I want to do?

I would like to build the radio car with which my grandfather had witnessed the half of the Russian campaign (Unternehmen Barbarossa) of the german Wehrmacht in the second world war.

Many people are already familiar with this radio car. It is the radio car on my startpage:

Citroen U23 Radio Truck Wehrmacht

This picture was actually taken by my grandfather in the winter of 1941 in the front of Leningrad. But the radio car accompanied my grandfather until the end of 1943 and the beginning of 1944. What happened to it then will unfortunately remain forever in the unknown.


It has always been my secret dream to rebuild, drive and maintain this radio car.

But the beginning is difficult, because: I have only a few pictures from my grandfather's photo album and it actually started with the fact that I first had to find out which type of vehicle it is.

But why do you already have your own website and are known in collectors circles... Surely someone will find who can accurately determine the car.
And yes, I was a lucky guy!
A friendly, in collectors circles well-known collector could identify the car very quickly: A Citroen U23!
Now I already knew what I wanted to build up there and could define a goal:

I will build an authentic, original (replacement-)radio truck (Ersatz-Funkkraftwagen) of the Wehrmacht. The carrier vehicle is a Citroen U23 (type 23).

Incidentally, the Citroen U23 was delivered to the Wehrmacht in relatively large quantities. The interesting thing is that it was not actually used as a radio car. And that's what makes it complicated, but more about that later!


So that's the beginning. I know the vehicle type. But what is next, logically?

At the beginning there were general considerations:


  • Do I have enough space to build a classic car of this dimension?
    • Yes, fortunately. We live on an old farm and even have a barn which is perfect as a shelter and workshop.
  • Do I have the time to realize this project?
    • Since I have wife and children you will have to see that. But there is no hurry. Whether it takes 2 or 15 years ... It is my intention to realize this project. And I'm burning for my hobby! So time will come. I'm not in hurry.
  • What about the costs?
    • Since this is a very long-cherished dream, I have already saved a lot. However, I have still calculated with a fairly high sum. How high the costs will ultimately be is not really calculable but I hope that my plans are reasonably correct.
  • For the radio truck body (Funkkasten), the know-how of engineers and craftsmen is required for the radio truck body construction. Do I have the necessary contacts to such people?
    • Fortunately, the most important occupational groups are in the family and in the circle of friends. I myself am also mechanical and technically not untalented by career paths.


From the friendly collector, I have received several tips. He himself has already restored and built two Kfz.17 vehicles of the Wehrmacht, so he has really gained immense experience and is certainly an absolute expert in this field.

An important advice from him: The radio equipment and accessories must be given special attention!
This means that in order to be able to correctly define the correct dimensions of the interior and also of the radio-cabin, most of the accessories should be present. Luckily I already have a lot of accessories. Some parts are still missing, but I will write more about it in another part of this project.

Incidentally, the radio truck body is the box-like truck construction that served the soldiers as accommodation for their communication activity. More details will be given in a later part of this project.


Here are two more pictures from my grandfather's wartime photo album:

Citroen U23 radio truck from the side


Detailed photo of a Citroen U23 radio truck of the Wehrmacht


There are still some more pictures available, but all are unfortunately in the "detail level" shown. The interior can only be guessed. So you can not really talk about "details".


To proceed as logically as possible I divide the project into three subprojects:

  1. Citroen U23 truck
  2. Kofferaufbau (radio-cabin)
  3. Radio technology and equipment


So I have the opportunity to work orderly on all three subprojects and then put them together at the end of the major project "Ersatz-Funkwagen Citroen U23" of the Wehrmacht.

Some facts collected so far on these three subprojects:


What we know about the truck:

The Citroen U23 was delivered in larger numbers to the Wehrmacht. Also, many were used as captured vehicles from the French and Polish army. It had a payload of 1.5t to 1.8t. These trucks were, however, usually used as a supply truck, at least that comes out of the mass of pictures I've found so far in the web. Apart from that I collect for over 20 years photos of radio vehicles of the Wehrmacht. I have never seen such a Ersatz-Funkwagen (replacement radio truck) (apart from this one). Whether te U23 was delivered to the Wehrmacht or whether it was a captured vehicle remains unknown for now.


What we know about the radio truck body:

In any case, this Citroen U23 is used here as a so-called Ersatz-Funkkraftwagen (replacement radio truck). This means that the soldiers have made a radio car from an existing vehicle by making appropriate changes to the existing truck body. As a rule, the truck body has been completely rebuilt and specially designed. But in exactly this truck body I am not so sure. Although there were truck bodys for the Citroen U23, but this radio "box" is special, because it seems as if it was made of sheet metal which is absolutely atypical for radio box body structures of the Wehrmacht.
As a result, this means that I still have to do a lot of intensive research here. Eventually, an existing truck body of the French was used. So the question is if there was such a box body?


What we know about the used radio technology and equipment:

Surely I know that there was an Torn.E.b. (Tornisterempfänger Berta) - the receiver - in the radio car. For transmitting there was a 100 W.S. in the radio car. (100 Watt Sender).
Both can be guessed with a lot of imagination. Certainly you can see in the last picture a wrapped Torn.E.b. standing in the door with it's accessory box. Possibly, there is even a Torn.E.b  standing in the background. In some pictures that I have here you can see clearly a 5m mast with a Schirmantenne 3/3.
Because of the devices and the stories of my grandfather, I also know what radio unit used this truck.
The setup must be done for a "Mittlerer Funktrupp b (Motorisiert)" what means in eglish something like "middle radio group b (motorized)" - (m.Fu.Tr.b (mot)).
I will write much more about these units in a later post on this project.


Due to the size, the equipment and all other information gathered so far, it is most likely a replacement radio car (Ersatz-Funkwagen) for a German Wehrmacht Kfz.61.


I am searching!

It's very important for me to get an authentic Citroen type 23 from the year of construction 1935 - 1943.

Therefore, I would now like to start a search request on my website and ask all readers to please share this search whenever possible and make public.


  • I am looking for an original Citroen type 23 from 1935 - 1943. Ideally, it is a delivered to the Wehrmacht or used as a captured vehicle by the Wehrmacht! The condition should not be very bad, but I still accept offers in any condition!
  • I am looking for original spare parts, parts lists and descriptions for the Citroen type 23 built in 1935 - 1948.
  • I am looking for photos, pictures, leaflets and instructions for the Citroen type 23 (U23) and its use in the German Wehrmacht.
  • I am looking for the following Wehrmacht service instructions (Dienstanweisungen):
    • D 942/1 - Funkgerät des mittleren Funktrupp b (mot.) mit Fu. Kw. (Kfz.61)
    • D 804/2 - Beladeplan des Kfz.61
  • I'm looking for all clues and information about the Citroen U23 and its use in the Wehrmacht.


Who has information, parts or even an original Citroen type 23 to sell, you can always contact me under the following data:




I am very grateful for any help, and about any other piece of the puzzle! :-)


Here you can find the articles published so far about this project:

Wehrmacht Ersatz-Funkwagen Citroen U23 Kfz.61 - Basics for replacement radio vehiclesWehrmacht Ersatz-Funkwagen Citroen U23 Kfz.61 - Basics for replacement radio vehicles

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