RE: Russle and Rodolfo on the TDA7000 I looked at single chip receiver ICs, they look really nice. I am confident that I could put together a "proper" radio with very little effort that way. In particular what I looked at was even more integrated: the Si4734 AM/FM/SW (short wave) digital receiver IC. Literally all I would have to do is hook up an antenna, a speaker driver, and a microcontroller (to send tuning commands) and I would have a completely functional radio. But, with this design I am looking to "get my hands dirty" with the NE612 mixer IC. I realize that what I've thrown together probably won't work the first time; I'm okay with that. If I can get my receiver (somewhat) working I'll be quite happy since it will be "my own" rather than a ready bought solution. (Although, the more I think about it, the more attractive the single chip solution seems to be. But, I still think I will save the something like the Si4734/TDA7000 for another time) On Sun, Oct 16, 2016 at 6:11 AM, RussellMc wrote: > More later maybe. > The then Philips TDA7000 may be of interest if you can find any. > Single IC RF/audio. > DC IF :-). > > !!! > https://www.google.co.nz/search?q=3Dtda7000&num=3D100&tbm=3Disch&tbo=3Du&= source=3Duniv&sa=3DX&ved=3D0ahUKEwjA09rOid_PAhUM0mMKHXZFAmgQsAQIIg&biw=3D15= 27&bih=3D836 > > Lonnnnng ago I used them in receivers for a data link for America's Cup > yachts. > TX x n in pockets on sails. > Cluster of RXs. > Strain gauges --> horsepower . > > Neither a NZ nor a US nor Australian challenger . > > > R > > > On 16 October 2016 at 11:23, Jason White > wrote: > >> Hello, as a personal project to become more familiar with RF circuits I >> would like to build an AM radio receiver. Online, I found a schematic wh= ich >> uses the NE612 mixer IC to create a Direct Conversion ("Syncrodyne") >> receiver. I have modified the design so that the local oscillator does n= ot >> need a custom wound transformer. >> >> In my case, I don't require the receiver to have very good performance. = I'm >> okay with the oscillator drifting and the audio "warbling" (due to >> frequency mismatch) under normal operation. >> >> I don't have any sort of matching network or filtering on the antenna >> connection; but I am hoping a 10m wire antenna will produce a sufficient= ly >> strong signal for the mixer. I am unsure how strongly signals and noise >> outside of the AM band are going to affect the receiver. Ideally, I'd ha= ve >> a buffer amplifier on the antenna input and a bandpass filter that cover= ed >> the AM band, but I want to avoid making this too complex. >> >> I have attached a picture of the original schematic, a picture of my >> ltspice schematic, and zip containing my ltspice simulation. >> >> I would like to know if my design (ltspice simulation) seems reasonable >> before I try to build it. I welcome advice on improving the design, but = at >> the same time I do wish to keep things a simple as possible. >> >> Thanks, >> Jason White >> >> -- >> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> >> > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist --=20 Jason White --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .