Is there a GB pot on the GTA 1000?

[willy]

How do you think the GTA 1000 PM compares to the GTI 1500 re. depth and sensitivity? Kinda curious insofar as I've read posts where people claim to see no real difference, save the imaging. Some actually prefer the GTA 1000. Go figure. I would be interested in finding out how the preset the GB for various detectors, in this case the GTA 1000 and Ace 250. Seeing as a closer to ideal GB seems to confer an increase in sensitivity, I wonder if they don't set the Ace 250 for really hot ground. ...Willy.

 

[Uncle Willy]

Yeah automatic ground balance means they set it to a chunk of ferrite at the factory.

Bill

 

[Hightone]

To BCDaddy:

LOL........your one step away from being a dealer. I bought and traded a few already, but only got into this last year. Agree on the Tesoro, great machine, but I like TID. After all my research, I love my CXIII, it has everything I want and works great for me. Sometimes I feel like I have a MBA in metal detectors, as I have read and studied every manual on all of them to see what they have and how they work.

To Willy:

I have looked at MY 250 once (will do it again this weekend) to see if it has a GB potentiometer that can be tapped into. You must be trying to add an external knob like Mr Bill does for the Whites Classic line. My engineering degree is in low voltage electronics, if its on there, I will find it. I can add a trigger to my 250 (like the Whites)that can be switched forward for AM mode or pulled for pinpointing rather than using the button on the face. But the AM mode on the Ace is not "true" AM mode, its just "accept" all metal during discrimination.

 

[jackintexas]

Hey Willy: There are two plastic plugs on the back of the GTA 1000 I am sending you. I don't know what they are for. Maybe like you said . Ground balance and ?....Jack

 

[willy]

Hey there Jack. I'm pretty sure that one of them hides a GB trimmer. It might even be possible (depending on how crowded the control box is, to stuff multi turn pot in there; sticking out the back. I also remember seeing these little extenders that snap into certain trimmers so that they then have a shaft; could probably make one up if necessary. That would save on the soldering, though it would be a bit tricky to adjust.
I've been wondering, for a number of years after testing a buddy's GTAx750, if there was some way to increase the sensitivity of the GTA/GTAx detectors. His didn't fare too well when compares to my original Golden Sabre on smaller gold. This could very well have been due to the GB setting. A few months ago I was testing an XTerra70 and, with the stock coil, it could easily pick up my 3 grain nugget. I had to run the sensitivity up rather high, but it could still do it. Such being the case, why shouldn't the GTA? They would both be operating at about the same frequency.
One thing that I rather regret seeing is Garrett going to the 8.5" coil on the GTA 1000 PM instead of the 5x10" DD. Granted, the iron disc. isn't as good with the DD and it probably wouldn't get the same depth (in mild soil), but up here it would be the ticket, both for handling the hot ground and for cruising through heavy trash. I'm going to see about picking one up cheap somewhere. True, I could stick on a Power DD, but those are heavy pigs though good in the water. I find that 5x10" DD coils do the best, especially on broken up terrain. Anyway, that's about it for now. ...Willy.

 

[BigCatDaddy]

Jeez, why not ask me a tough one!! I just got back from a morning of swingin' the 1500, which I hadn't done in a good while, and I had forgotten what a sweet rig it is, especially on target ID and pinpointing. I guess they are probably equal in depth, at least im my dirt, but depth ain't everything.
The 1000 with the stock coil is kinda tough to pinpoint with, being it's a closed pizza coil. You've really gotta pay more attention to hits on the lower conductivity stuff with the 1000 w/stocker as it doesn't hit them as hard as the 1500. I bought the Hothead Ferrett 5.5" coil for the 1000(after watching Skillet kick my ### with his) and you can jack the Sens. up and hit the LC stuff much better than with the stocker.
I did a test with the 1000PM, right after I got it, and the 250 where I hunted a median about 2 ft. wide in a school parking lot, both using their stock coils. First with the 1000 and dug everything that got a repeatable signal. Got a pretty nice pouchfull!! Went back over the same place with the 250 and dug 5 nickles and a few coins that the 1000 didn't even see.
After finding the second nickle, I got the 1000 back out, and on the next nickle signal with the 250, I tried with the 1000, just a small click. Now with the Ferrett attached, it's a whole different animal!! You can crank the Sens. right on up and it will get just a deep as the stocker and far better seperation and hits the lower conductivity stuff quite nicely. See Skillets post with that beauty of a gold ring!! I wish he would jump in here cuz he knows how to make that 1000 hum, I've seen the results in person!!
OK, I'm rambling now!! Probably didn't answer your questions, but enjoy the 1000!! It was the predecessor for the GTAx and GTI lines and will do the job for you. Happy Hunting!!

 

[adh247]

I was so happy to accross this thread! I noticted the same 2 pots when i disassembled my GTA 1000 ULTRA as well. They are right there in plain site... so for once and for all, can someone PLEASE tell Me/Us what these 2 pots do! I am dying to know seeing how i live near the beach at Cape Canaverjal and i do alot of beach detecting, but not near the water due to false readings from the salt water. So i would love to know what they do and if one is for Ground Balancing.... i also love the idea of extending the pot knobs outside the box for on-the-go tuning! That would be great. I am gonna tear down my gta1000 tomorrow and take some detailed pics of the insides for everyone to see what they actually look like on the cicuit board. I will post the pics tomorrow as soon as i get the unit apart ok guy. And thank you all so much for your help and appreciation in advance!

Anthony

 

[JB(MS)]

I was told by Jack Lowry in one of the phone calls I made to Garrett back in early 1990's that the GTA 1000 has kind of a limited auto ground balance. What I got from what he said was that when it was turned on with the coil close to the ground it automatically set the ground balance to sort of a preset window, for lack of a better word, that was correct for that spot of ground, but it didn't track the ground so the balance setting stayed the same unless it was turned off and turned on again.