DTM, Thanks for replying! I am making a shield, as it stands, there is no physical shield at all. The case is covered with spray on graphite on the inside, and has the shield wire attached to it with a piece of tape. Not only is graphite the cheapest EMI barrier, it is also the least effective. That said, mine is made of aluminium tape, multi layered. Now, the ideal shield would be platinum, or gold, or silver, or copper, then aluminum, and lastly graphite. I really couldn't go with copper, because of the shape of the housing, and needlees to say, the other material is not cost efficient. The tape could be cut and fairly easily manipulated into tight spots that would require an awesome amount of time if one were to use copper plate. The switch I bought, came from an auto parts store, but took heavy modification of the handle, so is not really practical when Tejon switches are readily available. By the way, you can purchase one of the stock switches AT Radio Shack, but agreed, they stink. And, my switch IS mounted on the handle, just forward of the grip and below the housing. Picture: An F-70 style set up with a switch for Ground Grab and pinpoint just in front of you trigger finger. You bring up a great point about the coil wire, and I'm very glad you mentioned it! Yes, just as you suspected, the wire is JUNK! However, without cutting apart the coil, I suppose I'll deal with it. It does have a Mylar shielding, but I have added additional protection on top of it! I, myself, picked up a semi- round rocker switch to be thumb operated, but having tried it, the machine didn't feel like I was holding it securely, and also the spot that it pretty much has to be mounted, is the absolute worst place concerning pole strength, and I feel would not be at all reliable. Great questions, thanks again so much for replying, Dan!!! Hope I explained it well enough. Good luck and great hunting, Regards, Richard. P.S. To take the unit apart, the handle must first be unscrewed from the pole and the foam must be removed to access the remaining screws, the wire running from front to rear must be detached, and finally, to take the electronics out, the knobbed switch on the front has to be removed, and to do that, one must remove the gold and black faceplate to remove the switch nut. It is foil, so you may want to take care!!
Hope you can put that bad boy back together! Are you working on that EMI shield? Thanks for posting this, I've always been curious how these looked inside.
I'm sure the '75 will be better than before, but only trial after trial will tell. I totally agree with you, the connector must be for future software downloads! As for what makes one more powerful, I suppose a good analogy would be, say, a Pentium 2 CPU from the late '90's, and the new quad-core CPU in use today. There are multiples squared of reasons one detector is more powerful, or better discriminating, but the hardware definitely plays a large part. However, the software must be programmed to make the best and most efficient use of that hardware! Like having a 500 horsepower car, you must press the accelerator to the floor to get the most out of it, or, you won't climb that hill!! LOL!! A person can take a mediocre detector and increase performance by doing a number of things to it. One being, take all the + or - 25% resistors out and replace them with + or - 1% resistors, more expensive, but if one cheap 25% one is 25% high, and another 25% one is 25% low, then there is a variance of 50% tolerance, and that is a lot of OHMS. Also, clock speed of the CPU and also the oscillators must be matched for best performance. And so on!! Well, enough of that! As for the switch trigger, no problem as far as the wires go, there are only three, the middle wire for search mode, and one each for GroundGrab and pinpoint. And speaking of the switch trigger, when I disassembled mine, the switch crumbled before the attachment nut came loose!! Modifying the area where the switch sits, relative to the control panel, isn't going to be much fun, if you intend to keep the stock pole assembly. If, however, you go with a F-70 style pole, then you may use a really sturdy switch, such as the Tejon uses! If you notice the small plug at about the one o"clock position on the lower picture, those are the switch wires, although the view shows what appears to be two wires, there are actually three. My net photogs will never win any awards, but I may try to post a few more, if they come out alright!! Thanks for showing interest, Ian! Perhaps we will learn something from this little adventure!! Great hunting and good luck, Ian!! Regards, Richard.
in my experience a lot of rf issues start in the long wires.
