
PaulTech
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PaulTech reacted to Fred in Price increases on DIP parts?
I've had no problem with 0.65mm pitch TSSOP on home etched PCBs. 0.5mm LQFP to follow soon. I did use hot air to solder though.
Go SMD. You won't want to go back.
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PaulTech got a reaction from chicken in [POTM] dAISy - A Simple AIS Receiver
MMICs are super easy to use at 162MHz, they're designeg to have 50ohm in &out, they just need a little power. Deadbug on a tiny bit of PCB.
the channel spacing for AIS is 25KHz and so the filter could be set a little big bigger 30-40KHz, not to much or more noise will get in , but a little wider to allow for any transmitters which either be drifting or have the modulation set a little too high. As you noticed too narrow doesn't work too well.
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PaulTech got a reaction from chicken in [POTM] dAISy - A Simple AIS Receiver
double the range is aout a 6db better sensitivity, so a MMIC at the antenna end or FET amp would easily get this result. The MMIC have the advantage of being very easy to work with. Even if the was a bit of filtering before the amp it should still get about an extra 10db improvement.
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PaulTech reacted to chicken in [POTM] dAISy - A Simple AIS Receiver
The Si4362 is only a receiver. For a transponder, you will have to look into the Si446x family.
http://www.silabs.com/products/wireless/EZRadioPRO/Pages/Si446x.aspx
However note, that GMSK encoding is only supported indirectly, which is fine for receivers but might not be up to spec for transponders. See this discussion: http://www.eevblog.com/forum/beginners/need-some-help-with-si4362-%28gfsk-vs-gmsk%29/
As for alternative sources for the IC, it looks like Farnell/Element14 has some in stock:
http://www.findchips.com/search/si4362
I currently use two kind of crystals, the larger footprint (5x3.2mm) is for this one:
http://www.mouser.com/Search/ProductDetail.aspx?R=7B-30.000MEEQ-Tvirtualkey57230000virtualkey717-7B-30.000MEEQ-T
I also use this smaller crystal (3.2x2.5mm) which is a bit out of spec as per Silabs application note (to large load capacitance), but works just fine for me:
http://www.mouser.com/Search/ProductDetail.aspx?R=AM-30.000MAGE-Tvirtualkey57230000virtualkey717-AM-30.000MAGE-T