Making a Gold Mountain (1650CEC & King Cobra)

Hoping this is the right place to post this, I'll proceed....

I've been sidetracked, thanks to the schematic of a Gold Mountain King Cobra coming my way.  I have a working GMT 1650 and some years ago, I opened it up, copied out the PCB layout and made another (a clone) to drive a spare 4 inch coil.  Much of the PCB was unpopulated and numerous connections were flying, so it was obvious that the PCB was made to serve more than one set of model electronics.  Well, reference to the aforementioned King Cobra schematic, reveals that the PCB (which bears the legend GM1 on the component side) was laid for the King Cobra and that the electronics for the GMT 1650 are mounted on a board that probably wasn't designed with dual model usage in mind.  I see things like a flying lead off a ground balance preset and passive components soldered directly onto the pins of chips.... half of an LF353 brought into use where the original copper had it idle (as per King Cobra schematic), etc....  Looks like the 1650 may have been an afterthought and was laid on the KC's board to save the not in those days insubstantial expense of designing another PCB.  All very interesting stuff and given the apparent interest in the GMT range of detectors, and their scarcity, I'm embarked on a project to construct a King Cobra and in due course, subject to satisfactory completion, to post any and all information that I'm able to glean with regard to the layout of the common PCB and the respective component placements.

Compliments of the season one and all

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		Quote:			Posted by galileo
	Hoping this is the right place to post this, I'll proceed.... I've been sidetracked, thanks to the schematic of a Gold Mountain King Cobra coming my way.  I have a working GMT 1650 and some years ago, I opened it up, copied out the PCB layout and made another (a clone) to drive a spare 4 inch coil.  Much of the PCB was unpopulated and numerous connections were flying, so it was obvious that the PCB was made to serve more than one set of model electronics.  Well, reference to the aforementioned King Cobra schematic, reveals that the PCB (which bears the legend GM1 on the component side) was laid for the King Cobra and that the electronics for the GMT 1650 are mounted on a board that probably wasn't designed with dual model usage in mind.  I see things like a flying lead off a ground balance preset and passive components soldered directly onto the pins of chips.... half of an LF353 brought into use where the original copper had it idle (as per King Cobra schematic), etc....  Looks like the 1650 may have been an afterthought and was laid on the KC's board to save the not in those days insubstantial expense of designing another PCB.  All very interesting stuff and given the apparent interest in the GMT range of detectors, and their scarcity, I'm embarked on a project to construct a King Cobra and in due course, subject to satisfactory completion, to post any and all information that I'm able to glean with regard to the layout of the common PCB and the respective component placements. Compliments of the season one and all

Hello . It will be nice to see your progress reports . I am sure you already know that the Gold Mountain models are a clone of the Golden Sabre original model , only with a dual tone audio added . Thank-you for sharing and posting this project with us !!

HH.........Eugene

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