The pitch of the tone.
In Conductive Tone mode coins should produce a high tone and iron should produce a low tone.
If all they are doing is breaking the threshold tone, it's because you have them both discriminated out. In every mode except All Metal you will hear a break or null in the threshold tone whenever the coil passes over a discriminated object. This is important to avoid missing targets nearby due to masking. In All Metal the machine registers all objects so the threshold is only broken by tones.
Try passing the coil over the coin, and then press the Accept/Reject button to see if it accepts it and starts producing a nice high pitch tone.
I have my safari programs crossed saved so it reads in ferrous tones. This puts iron as low tones and coins at high tones.
As far as the id screen, it works pretty good in clean ground but if there is a lot trash, it will show numbers differently than the tone. The trash will interfere with the id reading.
Go by the tones and type of sounds. If you have a high tone, then cross sweep it and find exactly where it is. Then put your coil over it and lift the coil about 3 foot off the ground and then come back down on the target and slightly wiggle it. This will give you a more accurate id number. This will work most of the time unless their is trash within a few inches of the target.
Listen for the high tones and a short sharp repeatable sound. Cross sweep the target and find center. Put your coil right on top of it and wiggle. Then look at the depth gauge to see who deep it is.
If it is very trashy, I will discriminate a lot and just cherry pic for coins. I will block most of everything below 20. It may cost me a few nickels. It will block out gold as well but I will go back later and lower the discrimination and dig more targets. Since there are always a lot of pulltabs, it can drive you crazy and if you block them out, it will block out gold as well. But I will block them out and cherry pick for coins and silver first. Then when I go back, it makes it less complicated to search for other items. Finding rings or jewelry on beaches is a common thing but pretty rare in my neck of the woods. I mainly just coin shoot. The park here is loaded with trash and I haul out a lot of trash. Some places in the park are so trashy, you can't make head or tails unless you discriminate.
Rusty nails, beavertails tabs, bottle caps, steel nuts and lead can throw a high pitch sometimes. If you circle the target while you swing, it will change the tone and help you determine if you need to dig. Pennies can give a silver tone sometimes as well.
My depth gauge works great. Just make sure you are over the target with your coil on the ground and give the coil a wiggle. Just like the id screen, it will pick up on near by trash and throw the depth reading off sometimes. The is a common issue with any detector. It takes some time to learn how to operate and read the tones and sounds of the detector and to set the coil so it id's the target accurately.
Make a coin garden and learn the tones and sounds of different coins and also plant some beavertails and pulltabs to learn their tones and sounds as well. Once you learn the coin tones and sounds, it makes it a lot easier. Don't be afraid to use you discrimination to quiet down the detector until you learn the coins better. You can always go back later and lower the discrimination and dig more targets.
