How serious are you about detecting as a hobby?? There's 2 directions for nuggets, just buy a good condition Sd pulse induction, they come up pretty cheap around the place, do a lot of research and have an extensive chat with Woody on making a simple frequency change circuit, use an old mono coil with around 2.2-3mhz frequency. Its not flashy but you simply don't need it, you need detector time with a minimum outlay but on practical and functional equipment that auits your experience, the less buttons and settings and shit the better off you will be. Jeez mate the stories I could tell you about the good ol days with my SD. Even up until we had a GPX4500 our SD's consistently found the biggest gold and that's a fact. I have worked the WA goldfields for 20 years, this works, many will dispute it and there are plenty of options, this is probably the cheapest of them. When you are ready you can pass it on to the kids or wife if you have cause to have them with you in the bush. The second direction for nuggets is simply this, spend as little as you can on the newest and best condition machine you can find and without being stupid a GPX5000 with the right set up and an experienced operator will do everything you will ever need it to. Don't fall victim to magazines and BS sales pitch. Listen to those who know, we STILL use the SD PI's, we STILL find more gold with our SD's in weight than with our GPX's. We work mega hot ground in 48 degree heat and pissing rain, find a mentor that wont bullshit you. Be WARY of even those you think are honest, loose lips sink ships and your patch will be gone before you know it and then the strike of country and cross-faults will be covered by those who know their shit before you can blink. You need to study the ground in your proposed area and look at the places where Gold was found by the old timers, NOTE the geology and rock type associations in detail where alluvial was recovered, gold is where gold has been found before. 3/4 of prospecting electronically is knowing the geology and reading signs in the country rock and intrusions, its a long road ahead young fella, but you will find your patch, it takes time and in the meantime it costs money but when you least expect it a buttery yellow thing will appear in the red dirt in your hand just before sundown and you will have achieved the first of many goals. Good luck on the Journey, stay safe and between the good times just enjoy where you are, the bush, the flies the spiders, centipedes and snakes. There's not a finer place to be, my utopia.
