OK, about time I started a thread on my latest pass time which I'm tackling in 40mins to 1 hour bites when I get some free time in between work and toddler taming.
WARNING: this thread contains gratuitous scenes of originality destruction. Please stop reading if of a nervous disposition or all about totally, utterly stock in every way!
The existing aftermarket radio is a complete wart on my totally stock interior. The objective is, to have a completely "stock looking" radio where all the buttons and knobs function, FM radio, connectivity for smartphone or other music device and 20w x2 RMS.
On-Vol-Tone will do what it says on the tin. Tuning knob will click left or right with a "momentary rotary switch" behind it and will click along the FM presets and act as next/prev track. FM far right will act as play as well as scan and tune button. AM far left will act as mode button for selecting radio or other sources.
The middle buttons will have a special set of functions.
Here is the radio, the last time it was whole as Mr Hitachi had intended.
And with knobs off (they just pull off)
First and foremost, it pains me greatly to take apart such a superb and intricate piece of mechanical engineering. (With an oscilloscope and some hours of tinkering I could have probably fixed it but it would still sound pants and not allow the connectivity I want.)
For example: Just look at the mini universal joint on the tuning knob and the clutch mechanism on the tuning wheel!!!! The clutch wheel moves sideways by about 3mm when a front button is pushed in and the UJ is there to accommodate that - how very cool!!!
The buttons operate a flat cam style plate that moves a slider (I think potentiometer). Each button had it's own precisely engineered wedge that moves a bar connected to the tuning wheel that moves ferrite cores in and out of inductors to vary their tuning properties - just awesome engineering. This level of mechanical and electronic integration / engineering brilliance we will never see again in our hi tech goods, a true lost art But then again, they are a LOT smaller, lighter and more feature rich!
These things must have taken sooooo many man hours to build. That entire circuit board and more now fits on a 50 pence piece size board + a power amp IC.
So first things first, cleaning off 40 years of finger grease and dead skin cells.
Amazing what could be achieved with a tooth brush and some silver paint.
The toughest part of the whole thing is to get the buttons to work with modern electronics. They used to move the clutch discs and a slider in ways I am too dumb to fathom.
These will have ultra miniature micro switched fitted. Fortunately there is a piece if metal that held in place inductors with moving ferrite cores for AM / FM tuning which fits the micro switches perfectly ...
WARNING: this thread contains gratuitous scenes of originality destruction. Please stop reading if of a nervous disposition or all about totally, utterly stock in every way!
The existing aftermarket radio is a complete wart on my totally stock interior. The objective is, to have a completely "stock looking" radio where all the buttons and knobs function, FM radio, connectivity for smartphone or other music device and 20w x2 RMS.
On-Vol-Tone will do what it says on the tin. Tuning knob will click left or right with a "momentary rotary switch" behind it and will click along the FM presets and act as next/prev track. FM far right will act as play as well as scan and tune button. AM far left will act as mode button for selecting radio or other sources.
The middle buttons will have a special set of functions.
Here is the radio, the last time it was whole as Mr Hitachi had intended.
And with knobs off (they just pull off)
First and foremost, it pains me greatly to take apart such a superb and intricate piece of mechanical engineering. (With an oscilloscope and some hours of tinkering I could have probably fixed it but it would still sound pants and not allow the connectivity I want.)
For example: Just look at the mini universal joint on the tuning knob and the clutch mechanism on the tuning wheel!!!! The clutch wheel moves sideways by about 3mm when a front button is pushed in and the UJ is there to accommodate that - how very cool!!!
The buttons operate a flat cam style plate that moves a slider (I think potentiometer). Each button had it's own precisely engineered wedge that moves a bar connected to the tuning wheel that moves ferrite cores in and out of inductors to vary their tuning properties - just awesome engineering. This level of mechanical and electronic integration / engineering brilliance we will never see again in our hi tech goods, a true lost art But then again, they are a LOT smaller, lighter and more feature rich!
These things must have taken sooooo many man hours to build. That entire circuit board and more now fits on a 50 pence piece size board + a power amp IC.
So first things first, cleaning off 40 years of finger grease and dead skin cells.
Amazing what could be achieved with a tooth brush and some silver paint.
The toughest part of the whole thing is to get the buttons to work with modern electronics. They used to move the clutch discs and a slider in ways I am too dumb to fathom.
These will have ultra miniature micro switched fitted. Fortunately there is a piece if metal that held in place inductors with moving ferrite cores for AM / FM tuning which fits the micro switches perfectly ...