SD2200/GP/GPX Frequency Tweak

[beepinpete_WA]

With the SD2200/GP Models we have a few tweaks also to get the buggers chirping along, they don't

have manual frequency tune settings but we can still fiddle and tweak that part up a bit by

using the Auto-tune button combined with the power on/off switch.

Now, most older operators know about high frequency VLF detectors and the way they are RED HOT on

small gold slithers, and Lower frequencies are better at penetrating deeper for larger gold.

So how can we fit a small or large coil on any SD2200/GP/GPX models and get even more grunt out of it ??

We all know small coils are made to aim at small gold, and larger coils are made to target larger deeper

gold, so if we combine our coil size used and the correct frequency settings, again thats when magic happens.

And on the SD2200/GP series the method to do this is as follows.

Small coils 6" > 14" Mono or DD Round or Ellip

Fit the coil and set your preliminary switch and knob settings on the front and rear panels.

keeping your finger on the power button while you do the next step.

Power up the machine and hit the Auto-Tune Button on the front panel and count

to 35-37 seconds then power off the machine.

this will halt the auto frequency tuning in a high frequency and make the detector

more sensitive to smaller shallower gold.

Larger 16" > 25" Mono or DD Round or Ellip

We go through the same procedures as above, but the counting time

is only 5 seconds before you power off the machine.

This halts the detector in a very low frequency which is Dynamite on deep

larger gold when running a larger coil..

Now, this tweak does have some limitations on when you can apply it, and the big nasty is EMI

or Electro Magnetic Interference.

So if there is quiet a bit of EMI give it a try but there's no promise the machine will run smooth

but you wont know until you actually do the tweak..

This Tweak can also be used on the GPX Series also by using the Manual Tune in the rear screen

Happy Scratchin

Pete

[frank c]

Beepin Pete I'm gonna give that a whril on the wifes machine next time out.

You guys are pretty cagy down there, (thats a compliment ! )

[beepinpete_WA]

Cheers Frank

Cagey is all good bruz, its payday for me today so I'll probably end up in the state cage later

Pete in WA

[wjbell]

I was JUST reading about that the other day. I kind of breezed through it and was going to post a question about it on this forum. Talk about coincidence. Thanks pete, gonna have to give that a try. One question, if you did the low frequency tweak on a coil like the 11 DD would it help it out in depth of bigger gold at all?

[beepinpete_WA]

G'day WJ

It may give a small fraction of extra depth on larger stuff if any, but the true depth will be limited by the coils actual size.

i would be more inclined to run the 11"DD in the high tweak, and after you have sussed an area with gold in it flick your

coil selection switch over to Mono and and run it as a Pseudo Mono.

Running any DD coil as a Pseudo Mono will change the way it signals targets, the center of the target response will now

be to the left center side of the DD coil.

Of course Running in Pseudo Mono will reduce your overall depth but give you the most sens from any DD coil to smaller

shallow nuggets.

Pete

[wjbell]

Alright, thanks Pete. Good info!

[Jonathan Porter]

Hi Pete, not trying to rain on your parade but feel this info to be relevant to your post. Firstly the variation between the high numbers and the low numbers is less then 10%, secondly with the slight increase in brightness of signal response on the smaller targets there is also a corresponding increase in ground noise assuming the freq tune ends up on a number that is free from interference.

Choosing a noisy tune position to work from can cut into outright performance to the point that it far outweighs the advantages sought, even a slight warble in the threshold can cost you dearly so keep it in mind when experimenting. A quiet running machine no matter what the frequency it's running at will always beat a tweaked but noisy machine.

Just my 2 cents.

JP

[beepinpete_WA]

G'day JP

No problems mate thanks for pointing that out to the members

I suppose when i put in this part of my post i should have made the text bold maybe

"Now, this tweak does have some limitations on when you can apply it, and the big nasty is EMI

or Electro Magnetic Interference.

So if there is quiet a bit of EMI give it a try but there's no promise the machine will run smooth

but you wont know until you actually do the tweak..".

Hows everything at clermont, i spose your getting your gear all sorted for the WA season by now,

the blokes up at Karratha look like they are in for a cyclone in a few days so i hope they

are all safely locked down.

Happy Swings

Pete

[wjbell]

It seems like the tuning process starts from the lowest frequency and scans to the highest frequency during the tuning mode. (Took a rocket surgeon to figure that one out ) And what I've seen with the 4500's and 5000's is that even manually tuning the frequency a couple of numbers can eliminate EMI's completely. So very little change in frequency tune can tune out the offending EMI.

So with this SD/GP tweak, maybe changing the second count a little one way or another will still lock you into a preferred (low) frequency while being adjustable in case the 5 second rule doesn't work in the area you're in. In other words, try 4 seconds, or 6 seconds. You're still in the lower register of frequencies, just adjusting it to suit your needs.

[beepinpete_WA]

It seems like the tuning process starts from the lowest frequency and scans to the highest frequency during the tuning mode. (Took a rocket surgeon to figure that one out ) And what I've seen with the 4500's and 5000's is that even manually tuning the frequency a couple of numbers can eliminate EMI's completely. So very little change in frequency tune can tune out the offending EMI.

So with this SD/GP tweak, maybe changing the second count a little one way or another will still lock you into a preferred (low) frequency while being adjustable in case the 5 second rule doesn't work in the area you're in. In other words, try 4 seconds, or 6 seconds. You're still in the lower register of frequencies, just adjusting it to suit your needs.

WJ

Your spot on with that comment mate, the theory is open to personalization to the area you work at any given time.

Pete

[leroym]

WJ

Your spot on with that comment mate, the theory is open to personalization to the area you work at any given time.

Pete

Pete, That's good information but I have a question.

Lets say I've started my detector (3500 W/16" coil) at low frequency and

I detect for a few hours and shut it down for a lunch break. When I start

it up again do I have to go through the same procedure as before?

I suspect that I would have to but wanted your opinion.

Thanks,

LeRoy in Montana

[wjbell]

Pete, That's good information but I have a question.

Lets say I've started my detector (3500 W/16" coil) at low frequency and

I detect for a few hours and shut it down for a lunch break. When I start

it up again do I have to go through the same procedure as before?

I suspect that I would have to but wanted your opinion.

Thanks,

LeRoy in Montana

It seems like it saves all those types of settings as long as you keep the battery connected. Same with ground balance. Not sure though, maybe someone else can verify.

[beepinpete_WA]

LeRoy

The detector will still be on the same frequency when yo restart it back up, but as the day progresses you

may find that the process needs re applying with a 4 or 6 second count instead of the 5 sec count

for low freq as the EMI shifts around a little.

For GPX users its just a matter of manually lifting/dropping the freq by a point or 2 only should it drift

as the day goes on.

Pete