The Evolution of Headsets and Throat mikes for Panzers (1935-1945)
The Evolution of Headsets and Throat Mikes for Panzers (1935-1945)
Though these days I choose to write more about Japanese militaria subjects, I actually have been a collector of German Army Panzer uniforms for over 40 years, and I look back upon the 70s and 80s, as a time when it was really hard to find headsets and throat mikes I desperately needed to finish a Panzer outfit. But things changed after the iron curtain came down and, to my great joy, they became quite available in the 90s onwards.
Many a collector of Panzer uniforms that can explain the differences between first type, second type and third type wrappers in minute detail almost never extend that level of attention to the headset and throat mike. However, perhaps because of the great difficulty I had in finding them in my early days, I have always appreciated them as something special, not a mere accessory. After all, the tank man became one with his tank through them, an important part of the man-machine interface. Thus since coming to Germany, I started to pursue this new interface theme and collected intercom, radio and instrument components of the tank. By definition, these were items that the Panzer man had to be totally familiar with, so they were also main subjects of the famous tank manuals, the Tiger and Pantherfibel.
Besides those manuals, of particular value to me in this regard was a German book, “Die deutschen Funknachrichtenanlagen bis 1945, Band 3, Funk-und Bordsprechanlagen in Panzerfahrzeugen” by Hans-Joachim Ellissen. Written by a radio specialist and former WW2 panzer radio man himself. It was an eye-opener that left me totally humbled by my former ignorance.
With the help of these aids, I was able to explore a fascinating area that uniform collectors rarely venture into. So focusing on headsets and throat mikes, I would like to show what you have been missing.
02-15-2016 09:04 PM
Typical Misconceptions about Throat Mikes and Headsets
Did you know that during WW2, crew in the same tank had to use two distinctly different headsets (models “b” and “d”) and two types of throat mikes (models “a” and “b”), depending on the role / station of the individual within the tank? Though they were not interchangeable at all, the external designs were identical, the only visible differences being limited to the plugs and markings. Therefore in wartime photos it looks like they were all wearing the same headsets and throat mikes. So most Panzer uniform collectors have long thought that one set of headset and throat mike was all you needed to deck out a Panzer uniform mannequin. If you are one of those collectors, it is now time that you learned how it really was.
The Standard Radio Setup
Before we start, I need to briefly touch upon the radio itself. A standard German tank platoon generally had its tanks equipped with an Ultra shortwave transmitter and receiver. The pair along with matching transformers had the designation “Fu5”, composed of a 10 Watt Type c transmitter (abbreviated 10W.S.c from 10-Watt-Sender c) and an ultra shortwave receiver type e (abbreviated UKW. E.e from Ultrakurzwellen- Emfänger e). This set operated on a frequency band of 27200-33300 kHz, and to be able to link to other tanks of the same platoon, had a usable range of 4 kilometers when transmitting vocally or up to 7 kilometers when transmitting by telegraphic morse code (tanks were also set up with a morse key for this purpose ). Platoon leaders had an extra UKW.E.e installed, as a second receiver to communicate with neighboring platoons (Receiver 2 ). In order to have more reach to communicate with regimental command or to communicate with Luftwaffe planes, other radio setups existed, and command tanks (Befehlpanzer) even had another radio set in the turret by sacrificing the turret machine gun, but I will not get into those, as this is not meant for radio enthusiasts.
In this article I will be assuming a platoon leader setup with 2 receivers to explain the various switching scenarios.
Panzerkasten 20, the turning point
For Panzer communication systems, the most important milestone came in 1941. Before this change, the headsets and throat mikes were relying on the radios for their power feed, and thus being underpowered, they did not have enough juice to bring the gunner onto the intercom network, and only included the radio man, commander and the driver.
Then finally in 1941 a new amplifying intercom box called Panzerkasten 20 was installed and cranked up the power output to finally allow the gunner into the communication loop, a much awaited improvement which was also echoed in the Pantherfibel, which exclaimed “The ultimate dream comes true: the gunner can now participate in the onboard communication! “ Thus the change increased the number of crew on the network to 4 out of a total of 5 for a Tiger or Panther.
The odd man out was the loader, but this couldn’t be helped, as his role required moving about within the tank to get the right ammo, so it was impractical for him to wear a headset and throat mike with cords. The system components for the intercom was totally upgraded at that time to a degree that the major units were no longer interchangeable, so it makes the most sense to explain the makeup of the system before and after the Panzerkasten 20.
Before the advent of Kasten 20
In the early days of the small Panzers, an intercom system was not yet possible. The main reason for this was that they still lacked an effective mechanism to supply power and communication signals from the hull to a rotating turret. Thus the Panzer IIs from model “a” to model “c” could have the commander listening with a headset, but he wore no throat mike. Instead he communicated with the driver “by touch”. For instance, touching the center of the driver’s back meant “Keep straight”, touching the head meant “Stop”, etc. The radio man was the only one to wear both a throat mike and a headset.
In 1938 the 8 track slip-ring power transfer device (8teiligem Schleifringübertrager) was installed in Panzer IIs, which allowed power supply from the hull to reach the turret through slip-rings that rotated around a circular drum structure. This finally allowed the commander to use a throat mike, but the driver still remained outside the loop.
Finally for the Panzer III and IV with the 5-man crew, an intercom system connecting multiple crew members was already anticipated from the initial design using the Z series intercom boxes. Commander, radio man and finally the driver were integrated into the communication system, but switching back and forth between external and internal communication still had to rely on an improvised method as explained below.
The intercom system was reinforced from 1st March 1940 by modifying the circuit of the radio receiver to supply amplified activation power to the 3 throat mikes. The radios thus modified were indicated by a vertical bar painted on the upper part of the front panel of the radio and were called “Gelbstrich-Geräte” (Yellow stripe devices). These early intercom systems, however, were still limited in function and needed to be supplemented by other means of signaling.
The radio man in a tank had the job of monitoring incoming radio messages, while the commander kept in contact with the driver. In this case, if the commander wanted the radio man on the intercom, he had to rely on a light signal to raise him. This also worked in reverse; when the radio man wanted to alert the commander to incoming radio traffic, he used the light signal. Switching between internal and external communication was also not yet an easy flick of a switch, but required re-plugging of the headset.
Headsets and throat mikes of early days
Throat mikes came on board Panzers initially for radio man use in 1935. The model then in use was the Kmf 4. (Kmf stood for Kehlkopfmikrofon, meaning Larynx Microphone) These would have been used also on the Panzer IIIs by the commander, radio man and driver. The switch box was mounted onto a strip of leather, and this provided the means of fixing the switch box on the uniform by a button hole at the lower end and a clip at the top end. Unlike the later throat mikes, on/off was done through the black and white buttons on the side, while the ribbed push button seen on the side in later models was located at the front on this model. The Kmf4 was in use until 1938 when it was replaced by its successor, the Kmfa, which also had a plug with 2 prongs.
Last edited by nick komiya; 02-16-2016 at 08:45 PM.
Here’s an early Kmf. b that exhibits transitional features. Notice the same cloth covering as the Kmf.4 and the way the cords come out of the capsule housing directly whereas later housings have a cord guide molded onto the housing. Also, the capsule in this model is marked on the back “Kmf.2, 36”. That means this was initially a Kmf2 made in 1936.
Kmf2s were the 3-pronged plug version of the Kmf 4 employed those days on the Torn. Fu. radios. Kmf2s were all recalled in 1938 for repair and maintenance, and some updated with the new style switch boxes introduced in 1938 (like the example shown) were used further on the Torn. Fu. b1 and f radios, while those used with Torn. Fu. d2 radios were all replaced by the new Kmfb throat mikes. This one could have been used in Panzers as a Kmfb after 1941, but most likely was used on the Torn. Fu. b1/f instead.
Early style of capsule housing
Late style Kmf. b capsule housing for comparison. See how the housing now has a cord guide. Come to think of it, this type of housing with blisters I have seen only on Kmfbs
The headsets worn since 1935 by the radio man would have been the Dfhb model (Dfhb stood for Doppelfernhörer b, meaning Double Headphones b model), but with orange brown natural rubber ear pads. He could wear this 2000 Ohm model, because he was plugging directly into the receiver and had enough signal strength.
The commander and driver on Panzer IIIs unfortunately could not use this model and had to resort to a 54 Ohm model called the Dfhd. This was externally identical to the Dfhb, but the actuators at the ears had diaphragms vibrated by two weak electromagnets each with only 27 Ohms (Dfhbs had two 1000 Ohm magnets) and the plug looked totally different with two short stubs as prongs placed close together.
Thus two different models of headsets were employed within the same tank.
After Kasten 20
In 1941 the new intercom box, Panzerkasten 20 was finally introduced. This box was positioned between the radio man and the driver and both of them plugged their headsets and mikes directly into this box. This box served as an amplifier for the intercom signals, as well as a switchboard, which the radio man operated to switch between incoming radio traffic and internal chatter, etc.
Everyone on board hearing all the internal chatter along with all the incoming outside radio traffic would have simply been sensory overload, so the intercom box switches and throat mike switches together allowed a complex selection of communication modes as to “who” heard “what”, so that each crew only heard what was necessary (more on the various modes later). Thus the radio operator was constantly busy as switchboard operator while also swinging the hull MG34 around with his head.
The Panzerkasten 20 got installed in all the new tanks rolling off the assembly lines in 1941, but tanks already in the field also needed to be retrofitted with the new intercom. For this purpose Umbauanleitung (conversion instructions) manuals for each type of vehicle were issued to troops in 1941/42. This change required all the Z series intercom boxes and connection points to be removed and replaced by new ones developed for use with the Panzerkasten 20.
Retirement of the Dfh.d Headsets
Let’s see now what this meant for headsets and throat mikes.
Before, only the radio man wore the 2000-Ohm Dfh.b headsets, and the commander and driver wore the 54-Ohm Dfh.d sets. Generally a higher resistance speaker/headset means better sound quality, so the good news was that everyone could now be upgraded to the 2000-Ohm Dfh.b headsets, including the gunner who newly could get online, thanks to the boosted signal.
Throat mikes already had the drawback of not being able to well reproduce consonants formed in the mouth like P,T,F,S and K, so listening to this with an underpowered headphone must have been quite stressful.
Anyway with this upgrade, the Dfh.d headsets were all taken out of service from German tanks and saw very limited use in later years in Police armored cars, which made use of the Z series intercoms retired from army use.