FuG16ZY - Purpose and Function in the Context of the Employment of German Fighters

The DCS manual does not really explain a lot when it comes to the communication and navigation equipment of the Dora. It states some facts, but the why and how is mostly left in the dark - it is a bit brief on a few topics. The FuG16ZY is not just a radio, it is part of the general concept of how the germans employed their fighters.

After studying various documents concerning the comms equipment of the Dora (i.e. various manuals for the FuG16ZY and internet resources), my understanding of the operation and of the usage of the comms equipment grew a bit. Yet, I am by no means a subject matter expert - not in regards to comms or nav equipment, nor of the way fighers were employed in that era. But I still want to share my findings - maybe someone else can make use of it, complement or correct it (would be much apreciated!).

Various, for us perhaps unusual terms are used for several concepts or topics:

• Ft, Funktelefonie - "radio telefony". The normal voice communication as we are used to it
  
• Abst., Abstimmung - "tuning". Basically radio homing on any radio transmission. This position of the switch allows the AFN2 to operate. (AFN2="Abstimmungsanzeiger"/"Tuning indicator" and therefore the operation mode is called "Abstimmung"/"tuning")
  
• ZF, Zielflug, Zielflugverfahren - homing on special ADF beacons. The AFN2 is again used to display signal information.
  
• AFN2, "Abstimmanzeiger" - "tuning indicator". You can see how good you receive a transmission. The operation of the AFN2 might differ between ZF and Abst. ... not really clear to me as of yet.
  
• Y-Verfahren, Y-Führungsverfahren - "Y Procedure", "Y Management Procedure". My understandng is, that the "Y Verfahren" is a concept of the Luftwaffe to lead their fighters to intercept enemy bombers. It makes use of strategically placed ground based radar installations (google for i.e. "Freya"), human observation posts across the usual bomber routes. Basically it is some sort of GCI, ground based intercept. A ground based controller directs the fighters to the bomber formations. The controller knows the position of the enemy aircraft and also knows the exact position of the available fighters. The position of a fighter squadron is determined by the so called E-Meßbetrieb.
  
• E-Meßbetrieb - "E(lectro?) Measuring Operation Mode". My understanding is, that the aircraft of the squad leader can be equipped with a system that allows the GCI controller to determine it's position. This system is (mainly?) the radio with the "Y" designation like our FuG16ZY. I think, it works like some sort of "reverse" radio homing: the ground station home in on the aircraft's sender.
  
• FuG16ZY, Funkgerät 16 ZY - radio type 16 with Z=Zielflug and Y=Y-Führungsfervahren capabilities. The AFN2 can be slaved to it to provide radio homing (visualisation) capabilities. The radio allows also to transmit for the E-Meßverfahren so that GCI operators can home in on it and determine the aircraft/squadrons position.
  

Channels of the FuG16ZY:

The radio has four separate frequencies for the transmitter and four separate freqs for the receiver. The channel selector on the left console is a remote control that switches the frequency on the transmitter and on the receiver accordingly. The frequencies of transmitter and sender do not necessarily (i.e. technically) have to match!

Depending on the planned use or configuration of a fighter (i.e. Tagjäger/"Day Figher", Nachtjäger/"Night Fighter", with or without Y-Verfahren capability), the channel I can be mapped differently to the configured channels of the transmitter and receiver (i.e. if the figher is not configured for Y-Verfahren, channel I can work differently). Our Dora seems to be meant to be used as squadron leader aircraft with Y-Verfahren capabilities.

• I - Y-Führungsfrequenz, "Y Management frequency". Transmitter sends on channel I (to the GCI operator), receiver listens on channel II (wingmen). The pilot can talk(??)/transmit a signal to the GCI while also still be able to hear what is going on in his flight. The transmitting on channel I is in fact the "E-Meßbetrieb" and you switch the mode selector to "Abst." (well, the lower position. I think, in fighters with this configuration the position should be labeled "Y". "Abst." is only for AFN2 homing?)
  The maintenance manual states that II is always 1.9 MHz higher than I.
  
• II - Gruppenbefehlsfrequenz, "Group Management Frequency". Frequency of the flight
  
• III - Nah-Flugsicherungsfrequenz. "Air Traffic Control".
  
• IV - Reichsjägerfrequenz, "Reich Fighter Defense Frequency". Country wide coverage for broader operations.
  

Questions, WIP?, inconclusive, to-be-tested (volunteers? :o)

1. Listening to the flight on channel II while you are set to channel I seems not to be implemented, as the DCS manual states. (DCS radios can only send and receive on the same frequency; different freqs are not supported. Yet?) If it is in fact impossible to implement this correctly, wouldn't we then perhaps want channel I to behave like the other channels, i.e. simply transmitting and receiving on the same frequency? Otherwise channel I is, as being not implemented, totally useless and lost for us. If I got the german manual right ("D. (Luft) T. 4069", p. 3 07) , then this would even be realistic: the different frequencies are only used on figher configurations with E-Meßbetrieb - aircrafts without that capability simply use ch. I as regular channel (minus ZF functionality?). In fact, I now believe that the mode switch is wrongly labeled. According to the aircrafts configuration, different lables were used:
   
   • a/c with E-Meßbetrieb: "Ft" / "Y ZF" for radio telephony vs. Y-Verfahren (at channel I) or Zielflug (at channels II - IV)
     
   • a/c without E-Meßbetrieb: "Ft" / "ZF" for radio telephony vs. Zielflug (only ch. II - IV, ch. I with "ZF" has no function)
     
   • a/c ...????: "Ft" / "Abst.": radio telephony vs. "tuning indicator".
     

[*]What exact fighter configuration is our Dora supposed to resemble?

[*]When using the AFN2 while the FuG16ZY is in "Abst.", transmitting should be possible. When in homing mode, a different antenna is used, but it can still be used to send transmissions - although the range is reduced. Is this implemented? Can anyone test in MP?

[*]Transmitting for E-Meßbetrieb: what exactly is when transmitted? Is it just a modulated tone or does the pilot really talk to the GCI operator?

Sources:

http://forums.eagle.ru/showpost.php?p=2087128&postcount=11

http://forums.eagle.ru/showpost.php?p=2112544&postcount=139

DCS Fw 190 D manual

German manual "D. (Luft) T. 4069" for the FuG16ZY; http://www.cdvandt.org/D-Luft-T-4069-FuG-16ZY.pdf

http://www.gyges.dk/Himmelbett.htm

Very good explanation and interesting questions.

Nice topic.

I always asked myself how it really worked. I miss the explanation in the manual too.

Thak you for such topic. Its very interesting and i want to learn more about it.

S!

For a higher level overview of GCI and radar at this period, check out

Instruments of Darkness: The History of Electronic Warfare by Alfred Price

http://www.amazon.com/gp/aw/d/068415806X/ref=mp_s_a_1_2?qid=1410552866&sr=8-2&pi=SY200_QL40

Very interesting! Thanks for the writeup.

Hope this will be implemented to some extent in DCS.

Subscribed.

Thank you for the research