I'd like to build a 433 MHz receiver from scratch. Is there a schematic or some material to learn how to build one?
Google search didn't come up with much in the way of building one from scratch.
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1\$\begingroup\$ We don't know anything about the application, data rates, protocols, range, channel bandwidth, link budget, co-located carriers, etc. So its pretty hard to give specific design information. \$\endgroup\$– user9224May 7, 2012 at 0:51
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\$\begingroup\$ Older ARRL handbooks. Older RSGB handbooks. Really. Google also know much if looking in amateur radio areas. Rushing ... \$\endgroup\$– Russell McMahon ♦May 7, 2012 at 1:16
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\$\begingroup\$ Start here and tunnel outwards \$\endgroup\$– Russell McMahon ♦May 7, 2012 at 1:18
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\$\begingroup\$ This is a rather neat 432 MHz rcvr - good starting point - follow leads to accompanying txs. \$\endgroup\$– Russell McMahon ♦May 7, 2012 at 1:19
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Sorry that I can't point you to an answer, but I can shed some light on why Google doesn't come up with much (my response is too long for a comment). The reason is very few designers have access to the equipment necessary to properly design a 433MHz circuit from scratch. Normal oscilloscopes are definitely out, and every little 0.1mm corner of a pad of your circuit board is actually a tiny inductor and capacitor connected to every other part of your circuit (parasitic/stray inductances and capacitances are killer at frequencies that high).
Also, the schematic of a 433MHz design is impossible to divorce from the geometry of the PCB layout. In other words, they would have to give you the schematic as well as the exact PCB geometry to make it work. Also, unfortunately, hand soldering is out due to parasitics. (Soldering an antenna on is one thing, but soldering the whole board is going to completely change the response of the circuit).
I don't mean to discourage you. I just want to make sure you know you're trying to slay a very big giant.
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\$\begingroup\$ I've seen 640 MHz circuits done with discretes. Everything was surface-mount, but not the smallest sizes (0805s and 1206's actually). There's no reason why it couldn't be hand-soldered. \$\endgroup\$ May 7, 2012 at 0:31
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\$\begingroup\$ True, it can be hand-soldered, but the soldering has to be a work of art. Also, not all VHF circuit types are created equal. A receiver would be just about the last thing I would want to tackle without some type of chipset. What type of circuit are you talking about @ThePhoton? \$\endgroup\$ May 7, 2012 at 0:44
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\$\begingroup\$ Considering the precision necessary and difficulty of making one of these work, I've searched for a receiver in devices i own. Is there a pattern or standard that can give me an idea of what the available leads do on this receiver: imageshack.us/photo/my-images/403/photohro.jpg \$\endgroup\$– JoeMay 7, 2012 at 2:20
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\$\begingroup\$ VCO. A receiver might be a bit fussier, but should still be doable. Justneed to know where your variability is and make allowances (trim caps). I hand solder things all the time for GHz digital. You need to be careful and have the right tools, but you don't gave to new some kind of soldering iron Rembrandt. \$\endgroup\$ May 7, 2012 at 3:51
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1\$\begingroup\$ @ThePhoton matches my experience, we made a Radar in one of my classes from etching our own PCBs and soldering on SMA jacks. This worked up to 16GHz by my memory. At 433MHz not every corner matters, your wavelength is 1 meter, I would say you are well below transmission line affects at 20mm. Yes, there is capacitance at .1mm, but enough to make a major difference, no. \$\endgroup\$– KortukMay 20, 2012 at 12:23
