[Aktungbby]

Originally Posted by scott_c2911

Im in grid BF43 and its 1100 on a November morning in 1943. Ive intercepted a submarine hydrophone contact only to discover its one of ours.
Immediately on surfacing to greet our new friend we spot a Catilina coming in to attack the friendly. We immediately man the guns and we manage to shoot him down. We took moderate hull damage and a little flooding defending the friendly who seemed unable to dive. An hour later 2 Mosquitos move in on us. I dive and the friendly does not confirming my suspicions so I resurface to continue defending the friendly who has not responded to repeated hails. We shoot them down between us.
Another Catalina arrives on the scene an hour later and attacks the friendly. Again we took damage forward after he swung round to spray us with machine gun fire. We succeeded in shooting him down too. Another attack is surely on its way. Hull integrity is 85% and I am low on ammo. What should I do? This is a bit of a no win situatiion.

http://www.uboatarchive.net/KTBNotesCommunications.htm

U-boats carried a suite of radio equipment giving them the ability to transmit, receive and direction find on several frequency bands. At the beginning of the war all HF and MF transmitters used forward jumping wire/antenna and the U-boat received HF transmissions on the trailing jumping wires/antennas. Because of the polarization of the wire, the boat sometimes had to point toward or away from the station it was transmitting or receiving to/from. Later a telescopic rod antenna extending from the port side of the bridge was added. U-boats received and transmitted messages in encrypted Morse code. U-boats seldom, if ever, transmitted or received by voice. The boat would have to be surfaced to transmit or receive messages on HF but could receive messages on VLF when submerged at shallow depth using the DF-loop antenna. Snorkel-equipped U-boats carried a drum-shaped aerial atop the snorkel which enabled them to transmit and receive HF while snorkeling. U-boats communicated almost exclusively with Control ashore. They did not send messages or beacon signals to other U-boats unless specifically instructed to do so by Control. A typical radio suite would consist of the following equipment:"

COMMANDER your position BF43 is the Bay of Biscay which in 1943 is a veritable zone of death well gridded by British Coastal Command who know too well the ways of our boats and the battery recharge times and have literally got the upper hand by this time.(Black May) Undoubtedly our codes are intercepted as well and a fourth rotor to the enigma is the solution. In short, do not engage any aircraft in Biscay; If you must communicate use VLF to receive from distress Uboat and Morse thru periscope with signal lamp to send msg! If schnorkel equipped use HF but the enemy is probably triangle listening. You are under no obligation to the stricken U-boat and as Kaleun, must not hazard your own vessel which has it's own mission. Remember a damaged uboot is nearly as good as a sunk u-boot to the enemy...the more so as our repair facilities are severely overtaxed (backed up) at the five French bases and the sabotage delay is only part of the problem; hampering redeployment in a timely fashion. Be aware that the enemy aircraft have painted blue instead of black and this simple ploy shortens your bridge crew's response time on 'alaaaarms' by five miles at over 100 mph- you do the math-remain heavy at 5-6 meters when in Biscay recharging batts! The fatherland thanks you in advance for your devoted service!