*** RX GAIN & BOTTLECAP REJECT ***

[cloudbuster]

Hi all. while out yesterday i was finding the field i was working quite hard work using my custom silver prog !!! On arrival i always do a fresh ground balance and also check best RX in probe. As a rule i usually have to set the RX 2-3 lower than the level given in probe mode to get a good stable detector with no falsing. well anyways cutting a lond story short i remember reading something somewhere about the bottlecap reject and thought i would dial a bit in as there was an awful amount of alu trash cans bottletops etc in the field i am working. i only dialed in 3 and it really smoothed the machine out got rid of all the trash bleeping nonsense and i was also able to set the RX to the level prescribed by probe. This may be all coincidence but it made my days hunting a much more pleasurable expierience yesterday.

all the best rob

 

[Monte]

i remember reading something somewhere about the bottlecap reject and thought i would dial a bit in as there was an awful amount of alu trash cans bottletops etc in the field i am working. i only dialed in 3 and it really smoothed the machine out got rid of all the trash bleeping nonsense

Rob,
In your post you stated: "an awful amount of alu trash cans bottletops etc."

Take note that "Bottle Cap Reject" was a circuitry design built-in with the older 5900 & 6000 and XL Pro models. It was a selectable & adjustable feature with the XLT, DFX, and such. This function helps to audibly reject some typical Bottle Caps, referring to the crimp-on or "crown caps" designs which are made of iron or some other magnet-based metal. It is not designed to assist with the taller aluminum Screw Caps as found on wine bottles and some other beverage bottles.

Also, remember that the V3 has a Double-D coil standard and, often, these have a more difficult time discriminating some trash, especially ferrous type junk. A lot will depend upon the coil used and the ground mineral conditions, but when I adjusted the Vision/Spectra V3 to a BCR of only #4, and using the stock 10" D2 coil, I had a very pronounced "break-up" in the audio that was a text-book Bottle Cap Reject audio. This was in an old school demolition site where plenty of rusty bottle caps resided, but I had a gut feeling to double check the signal. It sounded better with another detector w/950 coil. I recovered a 'V' nickels from less than 2

 

[cloudbuster]

many thanks for your observations monte. i was not completley sure how this piece of circuitry worked but it did appear to stabalise the audio for me on the particular program in use. I was using the 5'3 coil and like most i have created about three programs now that i am slowly fine tuning to work my fields. the soil composition does vary greatly on some fields running from very compact chocolate brown over clay to very dry broken soil with many voids. some areas are very very trashy where as other areas have very few targets.

One thing i have noticed though and i am sure someone with much more knowledge than i will be able to clarify is :- on some of my clean fields with little trash i tend to run in mixed mode to hear all signals, when things get a little boring i dig the occasional iron target to kill the boredom. why is it that i am able to detect very small iron targets at what appears much greater depth than a coin or piece of lead for example ??????

all the best rob

 

[Rob (IL)]

I know if I'm digging a piece of iron many times I know it's iron before I see the iron from the rust colored dirt all around it, call it a halo if you want. All the rust surrounding the iron makes it look a lot bigger to the detector. Your hammered coins don't do this. Rob

 

[cloudbuster]

I know if I'm digging a piece of iron many times I know it's iron before I see the iron from the rust colored dirt all around it, call it a halo if you want. All the rust surrounding the iron makes it look a lot bigger to the detector. Your hammered coins don't do this. Rob

I understand what your saying but some of the iron targets dug have been nothing more than nail heads, some of which i have dug @ 8"+. The V3 is a massive leap foreward from my xlt but there are odd things i am finding difficult to get used to. Another thing i am troubled over is foil. The xlt would warble and crackle everytime on foil but the V3 just gives a solid signal with super analysis screen (one day i will dig something gold LOL). Another odd one i had yesterday was a double whoop in the headphones which i had never heard before LOL. the VDI was +58 which is usually a halfpenny for me. On this occasion it was an old penny which usually hit @78-84 and was sat at 45 degrees just under the surface. the 2 main programs i am using are modified versions of HI PRO & RELIC the only real changes i have made are to the audio settings (i like to run my threshold at the same sound as my signal beep !! and deffo no tone ID) i have taken the modulation down to 1 on both programs and both are either running discrim at between 85-90 and all met at 60-65 RX i will run as high as i can without falsing. i am also using one extra prog (modified HI PRO @2.5mhz only) for strictly coin shooting with accepted targets from +20 to +94. I have had great success so far but still feel i am a long way off mastering this kiddie !!!

all the best rob

 

[Rob (IL)]

You didn't put your modulation down to 1, you put it up to one. You are running Max modulation. Remember the manual is wrong on this one. For me using the analysis screen foil usually will show the 2.5 close to flat or actually dipping to the negative.

I'm running much the same as you but I am running the modulation at 5 and am now going to try it off. In the less trashy areas I am also going to increase the recovery delay from the Hi Pro 65.
Rob