[Pisces]

Originally Posted by Zosimus

Good! Because, other than calling me a cheater, you contributed nothing to the thread.

I never personally called you a cheater. I did however say that the way the game displays the hydrophone bearings on the map, both in direction and length is cheating reality. This is of course not in anyway "bad" because SH3 is a game, and by definition it does that. SH3 is not a real simulator. And even simulators cut corners sometimes. So there is no need to feel threatened or consider your self attack as being a "cheater". If you want to play with the tools that the game gives you then that is OK and fine. I'm just saying in reality is wasn't so easy and reliable. Which I will explain next why I think that, based on the document you linked to. I have read it! In fact, I think I was the first one* that introduced it the SH3 forum to it by linking to this writer's site:

http://www.subsim.com/radioroom/showthread.php?t=130404

*: Ok, I forgot it was linked in the GWX 1.03 manual.

Why is the precise direction of the plotted bearing line 'cheating' reality?

Well if you read that document then you'll find that the bearing preciscion was very dependant on the frequency of the sound. Only with the higher frequencies (above 3 khz) could you get bearing precision narrower than 1 degree. Lower frequencies (in the order of 500Hz) give a much 'fuzzier' bearing, making the actual bearing somewhere in a range of up to 8 degrees. Which would make it a lot harder to find the center of the sound, just like listening to the sound manually at the station. And as higher frequencies decay in strength much sooner than lower frequencies these bearings would not have been as accurate at long range as the game portrays. Page 15 of the document you linked:

The British carefully investigated the capabilities of the GHG (Elac) apparatus in the captured U-570, in May 1942.
On successive selections of the high pass filters it was found that on the 6 kHz high pass-filter (utilizing the sonic spectrum between 6 kHz - 7 kHz), the bearing proved to have an accuracy of # 1°, for 3 kHz (utilizing the spectrum between 3 kHz - 7 kHz) the accuracy was . 1.5°, and for
1 kHz (utilizing the spectrum between 1 kHz - 7 kHz) the accuracy was . 4°, at 500 Hz, thus bypassing the high pass filters, the accuracy was decreased to. 8°.
Average merchant ships, cruising at 12-13 knots, produced a maximum sonic spectrum at 100 Hz and only 10% at 4 kHz. For destroyers cruising at 15 knots, the maximum sonic spectrum was at . 200 Hz, but still supplying 30% of its harmonic spectrum between, 4 kHz and 8 kHz.
Thus the proportion of sonic signal level left at the higher harmonics, had to be compensated for by increasing the amplification gain.

The question remains then how much this amplifier could enhance the higher frequencies without distorting the signal or flood it in self generated noise making it useless at longer ranges. This is hard to verify so long after the war, without first hand experience of the operators written down. (one of the conclusions of the writer)

Range determination based on hydrophone

The other place where I used the word cheating was in relation to the length of the hydrophone bearing line on the map in the game. Which as we know has the faint end of the line exactly ending at the source of the noise detected. Your eyesight, screen settings and antialias settings of your videocard determine if you get the right pixel spot on.
You state that the GHG or hydrophone had a resistor with which the signal strength could be reduced to determine the range of the source. You suggest that this variable resistor could be adjusted to get an absolute value on the range. Or at least get steps of 500m if it had 40 intermediate steps covering an expected max range of 20 km. However, I read that section about the resistor differently:
Page 3 of the PDF document:

All systems were subject to interference by the noise generated by electrical generators and other rotating devices, inside the submarine. The first step taken by the Germans to reduce this noise used a variable resistor parallel to the earphone circuit, a crude but quite common method used, in those days, to quantify the strength of a wireless signal. A special potentiometer was fitted with a 270 degree scale and was calibrated in ohms. The parallel resistance had to be reduced until the sound, in the headphone(s), had vanished. The signal strength was, for instance, considered as being 150 ohms. The value of the parallel resistance could indicate the increase or decrease of the sonic signal strength and allowed an approximate distance estimation, as well.
To reduce the man made noise picked up by the hydrophones, 1050 Hz band pass filters were inserted between the microphones and the earphones circuits.
The next step was to increase the system sensitivity, by adapting the valve amplifier used for the wireless station. Ships could now be observed up to 20 - 25 nautical miles, but greater attention had to be given to the reduction of man-made noise, from inside the submarine so as not to negate the improvements.

"could indicate the increase or decrease of the sonic signal strength"
- I read that as it could indicate a relative change in signal strength, and hopefully by relationship, distance.
What this means is that this resistor control could indicate if the sound source got stronger or weaker than to what it was calibrated. It does not say to which range it was calibrated. Which would require a known distance under the same conditions, which is something you don't have when you haven't located the target yet. In fact the writer mentions it is calibrated to a ohms value, not actual distance. And indicates that this can work upto 20-25 nautical miles, depending on the conditions. So, with background noises changing daily, or maybe even hourly due to the weather and internal conditions, this cannot be considered an indication of absolute range. It's only relative, and at best an indication of how much percentage wise the distance closed or opened up. That's why I feel the line length of the hydrophone bearing is not supposed to indicate the exact position. There is not enough variability in it to match the real world.

So, if you want to play the game as it is given then you should not feel offended by me using the word cheating. Especially as I wasn't personally addressing you. I'm just saying it lacks quite a bit in terms of realism, which understandably the game does not provide on all accounts.

Play as you like.