Spectra V3

[ivconic]

Was'n das? Cell phone? New IPOD? Or....

How to service this? As time goes by; less job for us - servicers!

Let's trace this!

[ivconic]

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[ivconic]

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[ivconic]

Just look ps stage!? Complicated!

[WM6]

As time goes by; less job for us - servicers!

And reverse engineer too.

[ivconic]

Yes !

At least we could take a look at TX/RX stages...

[kt315]

White's Spectra V3i the schematic, PCB, coil info are shared.

http://www.md4u.ru/viewtopic.php?f=94&t=8074

regards

[Skippy]

Headphone radio transmitter module:http://int.rsdelivers.com/product/cy...e/6571328.aspx

[Carl-NC]

Busy little devils!

[hdphilip]

how did he get the white paint off?

[ODM]

As long as it's not potted with chemically setting resins, it can certainly be serviced! It can often be easier to unmount a surface mounted IC compared to a through holed one without damaging the board, though methods are different. And it will be hard to plan a new product for through hole parts when they are steadily becoming unavailable. And designing a more complex and featured product is hard without it becoming hard to fit in a reasonable box.

I'd believe every manufacturer afraid of their designs being copied to include some microcontrollers .. or worse yet, fpga, on their product just to discourage that. And it is usually cheaper to ship a product with a microcontroller than design for fixed logic, and promise software upgrades - then you don't even have to ship a working product, like we see in more and more consumer electronics! Fortunately not with metal detectors, yet, except for the many scams and frauds!

[Davor]

It can work up to the point your FPGA vendor screws you up badly, as what happened some 14 years ago with Altera. In short, they failed to warn the "small" users on a major shift in their production that rendered all their funny little projects (smaller than 10 000 pcs) instantly obsolete.

[ODM]

It happens with some other parts as well, especially with performance components. Maxim is particularly frustrating to deal with. But yes, programmable devices are one way of making sure your circuitry will be a notch harder to replicate - though it's only a delay, not an obstacle.

Does this thing work with just a single square wave, or a repeated more complex pulse pattern, to create those three frequencies? The output isn't driven by a feedback loop, at least.

[Davor]

There are different ways to add disparate signals together. Common problem though is that you'd have to reduce the effective average signal value with each new source, and your peak (Vcc=const.) to average ratio soon becomes a problem. The average part that is.
You may wish to apply some tricks and rise the average value as much as possible, by shifting phases, allowing some distortion, or allowing some modulation, but that's not going to improve things by much. The safest approach is to optimise a lookup table with values that are repeated cyclically, that allows for some acceptable level of distortion, and that comprises of only binary values to avoid linear transitions. But whatever you do, every multi frequency transmitter will always suffer from the combining loss.

IMHO multiple frequency rigs are a passing fad. Problems related to the ground, sea water etc. are exactly the same and at exactly the same angle at all frequencies covered by these rigs, so the only advantage would be discrimination ... which works well enough with single frequency rigs as well.

[ODM]

Yes, there are many ways, but since it's about the V3 - what's the method used in it?