"Start!" I looked at the watch and it was about 5 a.m. If you look at the charts, the u1145 submarine has now approached the sea 30 kilometers east of the Shetland Islands. This distance is very good. Under the cover of the darkness, the observation points on the Shetland Islands and the patrol ships near the sea will not go so far. At this distance, the new antenna equipped by the u145 can clearly receive and locate the radio communication situation on the Shetland Islands.

That's right, radio reconnaissance. It's this era, who can only use your eyes to detect? As this plane radio technology develops in an unscientific way, the Germans' radio detection and positioning technology has also risen. The submarine is in a semi-submersible state, and the huge antenna begins to unfold and is aimed at the direction of the Shetland Islands.

Invisible radio waves were transmitted in the air, and soon the radio personnel on u145 identified five huge signal transmitting stations and marked them one by one on the chart. According to the channel analysis of the British Navy Fleet and Naval Air Force, Denitz quickly identified the other party's identity, three of which were the signal stations of the Royal Navy Fleet, which should be used by the airport. The other one was the signal stations of the British Large Fleet, but they were different from ordinary fleets. It was more like the contact frequency of the British seaplane troops.

"So, what we can be sure at present is that in the Shetland Islands, there are at least three airports for normal aircraft use in the UK and one seaplane airport?" Dunitz asked with a frown.

"It should be so. We and our colleagues from the previous batch have been monitoring the place for almost a week. Radio communication is very regular, and they are all effective communications. Starting at 5 o'clock every morning, these radio communication base stations will start working. Their main tasks will guide airport aircraft to dispatch. Most of these aircraft are twin-engine aircraft, mainly FB27 and O400. The main tasks should be reconnaissance and anti-submarine. There may be big guys like v1500 in the middle. The latter's radio equipment is more complete, and can be distinguished from the frequency and transmitter power." said Lieutenant Plitt, who was in charge of radio work who was transferred from the headquarters of the High Seas Fleet.

In fact, almost all the British bombers were shot down by the Germans, so the Germans were very clear about the radio communication equipment of British bombers. Different bombers use different levels of radio stations, the simplest is the only reception function, and the most complex ones have transceiver functions. These radio stations are generally used on twin-engine bombers. Unlike the British Army bombers, maritime bombers must be equipped with radio stations when performing missions, because the army can rely on landmarks to navigate. What should we do with maritime patrol aircraft? Especially in the North Sea, which is famous for its harsh weather... As for the radio station level of the v1500 bomber is one layer higher, with a larger power and a wider frequency band, and can even be used as an aviation base station to guide other aircraft.

According to the different communication methods of different transmitters, experienced radio personnel can identify information such as how many British bombers are in this airspace, their approximate locations, etc. After a period of reconnaissance, the data obtained by the German Navy is a bit terrifying!

"According to our previous and current information, in this sea area, the number of twin-engine bombers is about 120, and the number of v1500 is about 30. In addition, we can also see some DH9 and dromedary aircraft near the Shetland Islands. If we count at least 40 seaplanes near the seaplane, the total number of aircraft is at least 270. To be honest, I really didn't expect the British to come up with such a large-scale aircraft fleet." Lieutenant Plitz said.

"This does not include the British aircraft fleet in the Onek Islands. If I guess correctly, the twin-engine and above aircraft fleets of the British Royal Navy should be here. The British aviation power in this area is terrible!" Lieutenant Plitz said while drawing on the chart with the pencil at hand. He marked several newly exposed radio stations one by one on the chart.

Not that the German High Seas Fleet can really number every British aircraft that appears here. During previous reconnaissance missions, other German submarines also wandered in the British blockade area. They would record the patrol range, route and density of the British aircraft. Then, through these data, estimate the size and allocation of British aviation troops. Of course, this will also cost you while obtaining a lot of information. Two submarines were sunk and injured during reconnaissance operations within a week.

"If it is sunny, such a sea and air alert network can be described as airtight. Fortunately, the situation over the North Sea in winter is changing, otherwise our sea transportation will only be worse." Lieutenant Plitz said to himself while recording the situation. However, at this time, he saw Captain Denitz frowning at a newly calibrated radio base station. Because this base station is too close to another base station calibrated an hour ago! In fact, if it is an airport communication or guided radio station, it is impossible to set up so close, and there is no need.

"Didnitz ask, pointing to the map.

"I'm not sure about it here. Judging from the frequency and password, it should belong to the Royal Navy Air Force, but as you said, the radio stations here are very abnormal. We verified the frequency and transmission methods of the radio. Eighty-most probably the same. However, there is a deviation in the position." The lieutenant said when he saw the point of Dunitz. This node casts all kinds of weirdness. If the technical is correct, can this radio communication node be moved?

"Let's go and have a look!" Dengniz said decisively, why? Now everyone uses radio location too much. Have you forgotten the old methods of naval reconnaissance? Since you can't analyze the other party's situation through radio, then drive over and take a look. Although it is already dawn, the morning fog in the North Sea can still provide the submarines with very special cover conditions. According to the radio side data, it is only about 35 kilometers away from the submarine. Isn't it enough to walk over and take a look? Why do you have so much trouble?!

Denitz and his colleagues quickly determined their own position, and at the same time, based on intelligence, they operated on the chart and drew a curved route, which avoided the areas where the British often patrolled and possible minefields.
Chapter completed!