XL500 sample timing

[porkluvr]

He did it like this ->



A simple copy and paste.

Why does copy/paste work some times, but not others? It's not simple, it's whimsical. Is there some special technique? I am lost



Ctl+C, Ctl+V works within this window, and from this window to my computer, but not from my computer to this window.

[homefire]

Time for work here soon. I need to read your last post when I'm not so tired.

I use PhotoBucket.

Hyperlink to the photo.

If I Delete the photo in PhotoBucket, the link will show nothing but a error code.

Yes Stock Coil is unshielded. I think I will try other stuff before messing with the 555.

Need to take it out in the field and see what it dose too!

[porkluvr]

clarification

You will need different transmit pulse duration (RC timing at the 555 ) when switching to IRF740.

After doing some more quantitative (virtual) analysis, what I meant by that statement is that if you replace the BJT with IRF740 (making appropriate bias resistor changes, of course) but leave the original RC components on the 555, you will see about 11ma increase in current consumption. Counting only the transmit section, that's about 11% or 12% increase and, well, that might be OK, but...

You can simply parallel 100k across the 8.2k resistor between pins (2,6) & 7 to put current consumption approximately back to where it was. Transmit PPS increases about 10%, from the original ≈100, if my memory serves me.

The two circuits I showed in the post from which the quote was taken were selected based on their using extremely common resistor values, not because they are particurlarly special.

I reloaded my OS last night, and even though I had seperate partitions for OS and data - the reformat procedure went horribly amuck. Now, I am testing a new piece of software.
It's called R-Studio. I think the "R" stands for "Recovery", as in 'data "Recovery"'.

I'm sort of glad the HD in jeoprody is "only" 300GB.

[Qiaozhi]

Why does copy/paste work some times, but not others? It's not simple, it's whimsical. Is there some special technique? I am lost



Ctl+C, Ctl+V works within this window, and from this window to my computer, but not from my computer to this window.

It's probably because the image is accessible from the web, but if you cut and paste from your machine, then it can only be seen locally.

[homefire]

If it ain't broke, Don't Fix it!!!


My last famous words.

[Unregistered]

I've never done that

If it ain't broke, Don't Fix it!!!

But, take pictures of how it looked and how you took it apart if you do.

[homefire]

Yep! I made that mistake on some coil wires one time !

[homefire]

Been busy and sorta sick! Time to start this up again!

Glade to see the site is back too!

[Eugene52]

XL500 sample timing

If it ain't broke, Don't Fix it!!!


My last famous words.

IF IT IS AN INTERMITTENT PROBLEM , THEN HIT IT WITH A BIG HAMMER , A STEADY PROBLEM WILL BE EASIER TO FIX !!!!

[homefire]

Is that akin to the Drop Kick Test?

[Mrand]

Sorry, whether somebody has problems with the sight?

[Unregistered]

hi there

has anybody done any of these mods ...that we can try for th xl 500....more info needed please

[Unregistered]

I have tried these mods on my sea hunter xl 500 and the only one that gives a slight stronger depth is the 12k changed to a 5k mod...all the rest of your ideas guys does not work 1.2n and the irf740 only creates unwanted noise and a loss of about 30% sensitivity/depth....any other ideas please

[homefire]

Cool Beans! I never got around to the IRF idea. The resistor worked more then fine on the 500 and 200 models.

The cap change as you said caused chattering on the 500 but did work on the 200 .

I think this is due to the fact that the 200 uses a shielded cable and coil!

I simply moved the two resistors to a switch and can set to normal operation or the shorter sample rates.

The Cap mod is not worth the trouble to me. Faster Coil would fix that maybe?

[micheal]

I have just purchased used xl 500 .I have the 2 original coils small and large I am getting no more depth than my garrett grandmaster hunter vlf machine.I thought the PI machines where meant to have more depth ,My other question is It seems the tone is a pulsating tone ,is that normal or not ,it actually sounds similar to my home phone ringing ...what can be done to this machine to get more depth...will a newer more modern coil do the trick and what coils are avaliable to suit the xl 500 ,or is there a coil I can make for it.I noticed a resistor .5 ohm on the small board was not looking the best and around it on the board was kinda burnt any way the machine seems like its ok and working. I dont have another one to compare it to see if mine has problems...I think there is a tone problem although im not sure ....I appreciate any help on this subject.