Re: Hacking the Si4734: two more PDFs


sdwillingham
 

Wow! Nice bit of work Roy. I see you've drawn it sort of in the style that it's laid-out on the PCB. I'm a little confused by the circuit at Q1 and Q2, however. I think that those may be PNP transistors, which then makes some sense to me. They would be configured as common-collector stages, i.e. emitter-followers, buffering the high-impedance whip antenna.

The marking K16 matches these parts:
http://www.rohm.com/products/databook/tr/pdf/dta144gua.pdf
which are PNP "digital" transistors. I'm assuming these are surface-mount devices.

Thanks for drawing it all out! I love to learn about all the ways radio designers do front-end circuits.

-Scott-

--- In ultralightdx@..., "Roy" <roy.dyball@...> wrote:


Hi Phil

I took the time to draw out the G8 front end. The PL-310 and PL380 are
similar but with more components in the filter. The same is true for an
02-2010 model PL-300 which has a redesigned front end/audio board
compared to the original G8. Feel free use the diagram if you want to.

Cheers Roy.

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