VCO Mod

This mod is for a fine frequency adjust through different ranges to overcome noise and stability. I have had this mod on my detector for quite a while now (over 2 years) and I never released it publicly due to it being necessary to use 2200 end caps and also one part was extremely hard to find and that is the multi-turn external adjustment extension. I only sold one detector with this on and that was my original detector to a fellow in the US that wanted to try it. This is my detector:





In the above picture you can see the controls and following is an explanation of them.

Starting from the top (power socket) is the standard fixed frequency - On/Off switch (I just have a couple of extra frequencies). To the bottom left is a switch to change from Fixed to Variable system and on the opposite (bottom right of Fixed Switch) is the fine tune adjustment. The next knob numbered 1 - 9 are the variable frequency ranges. The reason for so many is to allow a greater range. If I had less the fine tune would be greatly reduced and therefore be rather coarse. Below is another picture of the frequencies:



As you can see I have a large range that I can cover and so far it has worked well in reducing interference and to a degree noise of operation. I haven't managed to use it much over the last 2 years and have really only been out for a few times totaling maybe only 3 weeks to a month. If I can make this work externally with a multi pin connector then I may release it publicly.

For those of you interested the other knobs are just Tone /Threshold and my inbuilt Audio Amplifier.

Hi Mechanic and Woody, The IC is LT6900 or LT1799 I may post the schematic but at the present would rather not due to it still being a current mod. I hope you understand. Thanks also Woody, yes it definitely quietens and stabalises the detector. Which type did you see? My original detector as in the photo (sniff, sniff my baby!! ) or a single turn pot on standard covers?

Yeah that's my baby. A very good detector that one. I certainly miss it!