PDA

View Full Version : Gain settings on E-Trac



DAN03USMC
02-13-2011, 08:12 AM
I was wondering if there is any correlation between the gain # and depth. Meaning...is it a sliding scale of sound where it is always the same depth distinction, with a tonal change based on gain #......Or, does the depth change based on gain #. Ex. if you are detecting and want to be alerted to targets say deeper than 5 would there be an appropriate gain # for this.......Or, would you only be changing the tonal sound on all targets based on depth?

Epi-hunter
02-13-2011, 09:15 AM
The gain setting is just an audio setting for any given signal, related to depth only in that at lower gain deep targets sound fainter than shallower targets and at high gain all targets are amplified. It doesn't change the depth indication in any way. If you wanted to better hear targets at 5 or deeper you could set the gain close to 30 and they would be easier to hear, but the gain setting doesn't change the signal strength.

Bell-Two
02-13-2011, 10:04 AM
I believe standard gain setting is 24 and many reccomend 28 to 29 to increase strength. The gain is sort of like a volume control if you turn it up you can hear the signal better but I have been told a higher gain setting in wet conditions can make the iron false sound better.

DAN03USMC
02-13-2011, 10:07 AM
E-H, that's not exactly what I meant. I wasn't sure if I was putting it right. I'm not talking about signal strength by way of the gain #, I was wondering if the tone would change at a given depth based on gain # I am making this part up......A gain of 15 wpould give you a different tone (target volume) on a target @ 8 than at a gain of 25. Meaning depth is the variable. At 30, all targets sound the same.....they are all amplified to sound equal. If you go down to 28 is the loudness linear Or does the Etrac choose a cut off point, and as the gain goes down does the cut off point move as well.
I am sorry if this is hard to follow. I am having a hard time writing what I am thinking. :)

Epi-hunter
02-13-2011, 07:10 PM
E-H, that's not exactly what I meant. I wasn't sure if I was putting it right. I'm not talking about signal strength by way of the gain #, I was wondering if the tone would change at a given depth based on gain # I am making this part up......A gain of 15 wpould give you a different tone (target volume) on a target @ 8 than at a gain of 25. Meaning depth is the variable. At 30, all targets sound the same.....they are all amplified to sound equal. If you go down to 28 is the loudness linear Or does the Etrac choose a cut off point, and as the gain goes down does the cut off point move as well.
I am sorry if this is hard to follow. I am having a hard time writing what I am thinking. :)

Actually, a full gain (30) does not make all targets sound the same. It is just the machine's limits to amplification of deep targets. You will still hear a distinct difference between deep and shallow targets. I think you were just using that as a hypothetical though, but I wanted to clarify that. :yes:

Not exactly sure what you mean by 'cut off point' but I would assume it is proportional. In other words, as you lower the gain you would get the same proportion of decrease of volume all the way.

coinnut
02-13-2011, 07:22 PM
If I am undersatnding this correctly, you are trying to tell between deeper signals and shallow signals using the Gain control as a way of doing it? The only way I can see about telling the depth (without looking at the depth guage for every signal) would be to set the gain at 1 (one). At 1, no signals would be amplified, meaning the deeper the target the quieter it would be. So you could only listen to the quieter sounds and they should be deep.The medium volume sounds should be medium depth and the loud sounds should be shallow. But I don't think you can set it for a certain depth, let's say 5 and up. The 5 target will sound a certain volume level, 6 will be quieter, 7 still quieter, 4 louder, 3 even louder. Kinda see what I mean?? The only drawback is a 9 target may be so quiet that you miss it all together unless you have great headphones and listen really carefully. Hope this helps some. This is the only way I could see to do it.

DAN03USMC
02-13-2011, 08:55 PM
Ok, nowwww I'm starting to get it. I use ratphones and have been using a gain setting of 30. I did this based on others saying it was the way to go. I have to be honest and say that I don't hear the difference in depth based on sound at 30. Maybe 30 is too subtle for my hearing. (I thought I had very good hearing). I have been bored lately with all the snow and have been messing around with air tests. I have passed targets by my coil at 30 thru 1 gain. I have to keep my sens low because I am indoors and get a max depth (distance) of 7 or so. At a gain of 14, I really only notice the lower volume at 5-6 from the coil. That would be the last 20% or so.
I think I am going to have to wait til I can test it out in the field on real targets. I read some where if you have DEEP ON, FAST OFF, and set your gain a little lower it is a great combo. I was also thinking wouldn't it be nice if it were reversed so that the shallow ones were soft and only the deepies were loud. I think that would be a plus.

DAN03USMC
02-13-2011, 09:09 PM
Oh,I forgot to metntion part of my first question. from what you are telling me, as you lower gain ALL tones shift softer as they get deeper. starting at 0 to the deepest signal. and not at a given depth, say 4(what I thought may be a cut-off point) to the deepest signal. I think I have got it now. I think my air test differs from what the book says.

coinnut
02-14-2011, 06:24 PM
The way I understand that control is: if the gain set at 1, all targets respond and are not amplified in any way. So the closer ones are loud and the deep ones are quieter. If the Gain is set at 30 all targets are loud..meaning the deep ones and the medium deep ones are amplified until they are as loud as a very shallow target. The numbers in between are a bit harder to describe. If you look at page 61 in the manual it will show you a diagram that will probably explain it better than I can lol In a nut shell, if you want the machine to react like the old analog signal sounds (whispers if you will) set it at 1 (and be prepared to miss the deep ones :yes:) If you have bad hearing and you want to hear everything loud - set it at 30. If you want to have some differences between deep, midrange and shallow targets set it in between 1 and 30. 15 is a good starting point and if you want the mid and deep targets to be a bit louder raise it to 20. I may be wrong, but that is what I think the manual is tell me rofl