Modded GP3500 info?

[user 4485]

Nah I'm getting it mixed up with the Pulse Delay. The TDI's have a pulse delay setting from 10us through to 25us.
They recommend using 10us for nugget hunting & to turn it up for coins/relics to help eliminate foil etc. I was getting the lower pulse delay setting mixed up with the frequency mod setting which I've found is "Generally low is deeper and for larger targets and up is for smaller targets" pretty much as SP wrote.

 

[SteelPat]

Thats right with delay. The delay isnt so much with the pulse - the delay time is the time between the last edge of the pulse and the time the receive gates open. Gold has a very short decay time, you need a relatively small delay compared to other metals.

 

[AuMan]

Hi Mbasko, That looks like a Detectormods job to me. He was using those dial type adjusters during the last year or a bit longer.
The gain is the front end gain. If you are having trouble ground balancing, back it off. I don't know where the standard gain setting would be. The hotter the ground, the less gain can be used. If it is used on pipeclay, crank it as much as emi/noise will allow.
For the frequency, the higher you set that, the more sensitive the machine will be. If you are getting too much ground noise or hotrocks, back this one off. It then becomes a compromise between gain and frequency, vs coil size.
If using a small coil, aim to have the frequency higher, if using a large coil, you will want the frequency lower.
Another trick would be to use the salt timing if you can't get things working right, it will be a bit more forgiving with the coils.
Last but not least, this is probably one of the most important things with modded detectors, coils. From my experience and testing, the Evo coils are the absolute best coils to use to get the most out of a modded machine. Other coils will work, but it can be hit and miss as to which will and wont and if you use a substandard coil, you might as well just use the machine in the standard settings, so the mods become pointless.

Hope this is helpful..

 

[old hand]

That's a woody mod just contact him for instruction a BALLARAT regards john

 

[user 4485]

Thanks for the replies. I've been in contact with Woody & waiting for him to verify that it is one of his by checking against the original owners name.
It'll actually be interesting to get some feedback on how it goes from someone I know personally & trust + possibly get to have a play with it myself.

 

[Elsewhere]

Try freq at 4 and gain at 7 sense deep in quite ground normal deep in noisier ground. Best coil is standard 11 inch dd. This setting has been my go to setting on my mod 3500 for last 5 years. Will still get .2 and still has good depth with the gain in 7. The higher the gain the deeper it will go but they tend to get noisey over 7. The lower the freq the bigger the gold but at 4 it will still get down to .2 all the best elsewhere.

 

[neddy]

Modded 3500. I had mine nodded by Ismael about 2 yrs ago. I was up at Jupiter Creek first day. Turned it on walked straight down the main walkway and picked up a 2grm nugget within 20mts. Hundreds of people have walked down that track swinging detectors me included. It was down about 8 inches, in centre of track. I have compared my machine to my mates 4500 on smaller pieces close to surface it matches if not betters the 4500.
In noisy ground the 4500 runs quieter
and its easier to hear signals. The 3500 has a smooth mode which performs well but looses some depth in noisier highly mineralised ground but still beats the performance of the original machine.. I have fitted woodies, small lithium batteries as well as his anti interference device. The machine does run much more smoothly and better than standard. I am happy with the machine.,