Chase Goldman Posted November 3, 2021 Share Posted November 3, 2021 3 hours ago, NCtoad said: Chase, could you please explain in layman’s terms what PWM and square waves are. Is this something we can switch back and forth between on the detector? An example of a square wave is shown below compared to a sine wave. Square waves are easily generated by quickly switching transistors off and on and were used by early digital sound synthesizers to emulate the smooth sine-wave sounds of analog audio ssources. You change the frequency of the square wave over time (pulses per second) to generate different tones. However, square waves introduce a lot of harmonic distortion compared to pure sine wave audio. This gives square wave audio it's distinctive fuzzy digital robot tone. PWM (pulse width modulation) is a special type of square wave where each pulse has a varying width (vice frequency) over time to generate varying tones, this enables a digital audio source to better approximate the rich tone of a sine wave so it sounds fuller and less distorted/fuzzy. It's not entirely clear to me why XP is not just solely using PWM, but perhaps there are situations where fast square wave audio provides enhanced target audio depending on whether you are using discrete target tone ID or pitch audio which gives you both intensity and pitch based cues on target signal strength and footprint (think pinpointer). HTH 5 1 Link to comment Share on other sites More sharing options...
Guest calabash digger Posted November 3, 2021 Share Posted November 3, 2021 8 hours ago, Chase Goldman said: Obviously price and release date are still unknowns but impressed with what they DID reveal including designing this as a full up medium duty dive detector. The other features look great (wide spectrum SMF, plus full up continuous single frequency capability across the 4 to 45 khz spectrum and the advertised audio options fill the bill for me. Impressive. Computer aided or phone app aided programming of the custom programs would be a bonus. The submerged wireless capability remains a little murky to me. Perhaps they are using the shaft/stem as a near field antenna. I noticed, however, the bone conduction phones appear to be WIRED (see the screen shot from the new Deus II page below). Might explain the connector port on the rear of the control module. Making a practical, reliable submerged wireless platform may have been the technological hurdle XP needed to overcome to get Deus II on the street vs. the actual FMF detecting tech. I guess the folks who don't care for wireless coils are out of luck, though. Can't wait to see more on the specs and features. I use dive computers and the have wireless tank modules that transmitt to the wrist computer... I wonder? Never mind just read the whole thread...I can see the wire.. Link to comment Share on other sites More sharing options...
Xergix Posted November 3, 2021 Share Posted November 3, 2021 11 hours ago, Dan Fox said: La bobina è sicuramente cablata per l'uso subacqueo. I don't think it uses connectors but only a link with two antennas to contact the coil and the remote control via clips. 2 Link to comment Share on other sites More sharing options...
strick Posted November 3, 2021 Share Posted November 3, 2021 There is mention of a screw kit on the brochure... what is that for? strick Link to comment Share on other sites More sharing options...
GB_Amateur Posted November 3, 2021 Share Posted November 3, 2021 18 hours ago, ☠ Cipher said: Here’s the choice of freq OK, I understand the Left Hand part of this graphic, but the RH? (Full disclosure: I don't understand French. ) The red lines are for FMF operation and the others represent different single frequency operations. But what specific performance advantages are being displayed? Here are some thoughts (which may be all wet): 1) You can't beat FMF in performance with any single frequency; 2) for iron discrimination and for large targets, there's a monotonic performance relationship with frequency; 3) for small targets, the opposite relationship (i.e. opposite compared to large targets) holds; 4) for medium targets, all single frequencies (as well as FMF) perform equally. I don't think I'm overstepping to say that this diagram is just a general 'rule' and that exceptions abound. Which end of the frequency spectrum caters to large targets and which to small? (If gold detector performance is any indication, higher frequency for small, etc.) 1 Link to comment Share on other sites More sharing options...
palzynski Posted November 3, 2021 Share Posted November 3, 2021 2 hours ago, GB_Amateur said: OK, I understand the Left Hand part of this graphic, but the RH? (Full disclosure: I don't understand French. ) .... I do understand French but it did not help me much to understand the graphic 😀 😀... 2 Link to comment Share on other sites More sharing options...
PimentoUK Posted November 3, 2021 Share Posted November 3, 2021 The graphic is showing the 7 frequencies, and their relative strengths for the 4 criteria shown. So you see the highest freq is good at finding the smallest targets, but isn't that clever at discriminating iron. 2 Link to comment Share on other sites More sharing options...
NCtoad Posted November 3, 2021 Share Posted November 3, 2021 Besides target size, doesn’t conductivity play a part in this graphic also? Or should I say, shouldn’t target conductivity be included in this graphic? Link to comment Share on other sites More sharing options...
PimentoUK Posted November 3, 2021 Share Posted November 3, 2021 "Shouldn’t target conductivity be included?" I agree, it's a bit vague, especially coming from XP. It's not just 'size' , it's the electrical characteristics that determine whether it's up with the big milled copper/silver coins or down with the thin ladies finger rings. But it seems that manufacturers never speak of the target frequency ( 'corner frequency' / -3dB frequency ) , even though that's exactly what they are measuring on a 'Target ID' scale. Link to comment Share on other sites More sharing options...
Chase Goldman Posted November 3, 2021 Share Posted November 3, 2021 7 hours ago, strick said: There is mention of a screw kit on the brochure... what is that for? strick Can you be more specific about which brochure you are referring to? Thanks. I can’t find anything other than the updated compatibility chart ID’d as a brochure on the XP website. Link to comment Share on other sites More sharing options...
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