AM FM Tuner .? - Page 1
Forum section: electronics / projects

author: Hextejas
author_rank: Frequent Contributor
timestamp: February 20, 2019, 10:44:15 am
content: Since I am almost finished with my preamp, phono stage, and amp, I would like a recommendation for a tuner as I realized that I still like to listen to the radio.Thanks.

author: Zero999
author_rank: Super Contributor
timestamp: February 20, 2019, 11:32:31 am
content: It depends on your requirements.No doubt there are plenty of tuner ICs available, many of which require an MCU, or you could do it the old way, making a superhet using discrete components and op-amps.

author: amyk
author_rank: Super Contributor
timestamp: February 20, 2019, 12:18:59 pm
content: Quote from: Zero999 on February 20, 2019, 11:32:31 amYou can get single-chip radios too (nothing but a few passives required), but I suspect the OP wants to make a discrete one.

author: vk6zgo
author_rank: Super Contributor
timestamp: February 20, 2019, 12:26:25 pm
content: Quote from: Zero999 on February 20, 2019, 11:32:31 amDon't use op-amps, they are not optimised for the job.There are many specialised ICs, or you could build it "retro style" with FETs or BJTs.Remember, an AM/FM radio is effectively two radios, as the operating frequencies, IF bandwidths, & demodulation methods of the two services are so different.

author: Richard Crowley
author_rank: Super Contributor
timestamp: February 20, 2019, 01:18:22 pm
content: AM ("MW" in some places) and FM radio technology lives on in car radios even after it is disappearing elsewhere. Building a proper broadcast (AM or FM) receiver is hardly worth trying here in the 21st century (IMHO) because the traditional technology of multi-stage IF strip requiring special transformers and proper RF circuit construction requiring specialized test gear, etc, etc. Modern vehicle radios are made with specialized IC technology that eliminates most of that complex circuits of traditional receivers.I have a similar project and have decided to just use a ready-made module for AM/FM reception. These things are avilable fully assembled and tested for far less than the cost of buying the individual components (if you could even find them at retail). For example, a separate module like this...https://www.amazon.com/Bluetooth-receiver-Digital-digital-Playback/dp/B073PQWXMKOr a panel-mount module for integration into the whole project...https://www.amazon.com/CTYRZCH-Bluetooth-Decoding-Module-Remote/dp/B07H2W2JX2

author: Richard Crowley
author_rank: Super Contributor
timestamp: February 20, 2019, 01:28:03 pm
content: Or a AM/FM receiver IC/module like the Silicon Labs Si4730/31 AM/FM Radio Receivers. But, of course, it requires a micro-controller and user interface to control it.https://www.amazon.com/BELONG-SI4730-V2-0-Radio-Module/dp/B07DPN6YL1

author: nsrmagazin
author_rank: Regular Contributor
timestamp: February 20, 2019, 01:44:49 pm
content: One of these can work too. And the whole FM tuner module is about $5 USD.http://www.cfcbazar.com/shopcategory/active-components/?WordApp_launch=&WordApp_mobile_site=&WordApp_demo=&WordApp_mobile_app=&orderby=latest&order=DESC

author: SiliconWizard
author_rank: Super Contributor
timestamp: February 20, 2019, 03:05:14 pm
content: I've used the Si4735 a few years ago, and it had pretty good performance (with RDS as well). It has I2S outputs so if you are dealing with digital audio in your system, that's a bonus. The Si4703 is a bit simpler to integrate, but not as good IME (and I think FM only). Both will require programming through SPI, but that's rather straightforward. There are variants in the same product line so you can pick whichever fits your needs best. If you're looking for an IC, that would be a good option. If you're looking for a ready-made tuner, there are probably dozens out there but beware most of them are utter crap.

author: Audioguru
author_rank: Super Contributor
timestamp: February 20, 2019, 09:17:56 pm
content: I listen to music on the internet and on TV. My clock radio wakes me sometimes playing commercials on an FM radio station.He said PHONO. I think I remember those old vinyl things that rotated and produced Click, Pop, Click, Pop all the time. How about an old cassette player?I still have an old portable MP3 player with a hard drive as its memory.

author: james_s
author_rank: Super Contributor
timestamp: February 20, 2019, 09:54:20 pm
content: It's funny when people talk about vinyl making pops and clicks, that was how I remembered it as well but then after someone gave me a box of records that had been well taken care of and I cleaned up an older but quite reasonable turntable I was very impressed. Properly taken care of records sound very good and it's quite a different experience playing a record album. After years of exclusively using digital music I've been collecting records and using them far more. I was surprised to find that vinyl has come back in a big way, quite a lot of new music is released on it now and apparently much of this is driven by the millennials. Personally I'm more into finding interesting old albums at thrift stores, I've dug through a lot of junk but found some real gems.Now I'm no audiophile but looking back I realize now that the records I had when I was a kid were abused cast off junk and the record players I had access to were cheap low end crap that was likely worn out and out of adjustment. Now that I have something with a proper elliptical diamond stylus and records that have not had their grooves hogged out by worn out cheap needles on those brutal 20+ gram tracking force toy record players the sound is every bit as quiet as a CD at least to my ears. People who think they sound bad have never listened to a good setup, and by good I don't mean high end megabuck audiophile stuff, the sort of turntables that sold for <$200 in the 80s are fine. More important that the stylus is in good shape and everything is dialed in properly.

author: rdl
author_rank: Super Contributor
timestamp: February 20, 2019, 10:14:13 pm
content: The car audio manufacturers are making "disk-less" or "mechless" receiver units now. One of those might be adaptable, with the added benefit of playing FLAC or MP3 from SD cards. I'm thinking about getting one for my bedroom system since I can't seem to find a "disk-less" CD player. Though I may just settle for some kind of streaming solution.

author: james_s
author_rank: Super Contributor
timestamp: February 21, 2019, 12:23:33 am
content: There are plenty of "MP3 player" walkman style devices that do exactly the same thing, play music off internal flash or a micro SD card, many of these contain an FM tuner as well.I've played with those little tiny direct conversion receiver modules, they actually work quite well provided you have a microcontroller to run them.

author: schmitt trigger
author_rank: Super Contributor
timestamp: February 21, 2019, 01:49:45 am
content: The OP perhaps wants to build a tuner the old fashioned way: ganged variable capacitors, IF transformers, and discrete components found in a classic superhet circuit.But he has not replied yet, so we can’t know. Perhaps he was intimidated by all the digital radio suggestions.

author: james_s
author_rank: Super Contributor
timestamp: February 21, 2019, 02:42:55 am
content: I do think it sounds fun to build an old fashioned analog tuner although it could be a fairly difficult project. Perhaps a compromise using a few more modern ICs would be worthwhile, I remember there being some analog "receiver on a chip" ICs that do most of the heavy lifting. Some simple AM/FM radios didn't have much inside.

author: ebastler
author_rank: Super Contributor
timestamp: February 21, 2019, 04:57:42 am
content: Quote from: rdl on February 20, 2019, 10:14:13 pmYes, these are hard to come by.

author: duak
author_rank: Super Contributor
timestamp: February 21, 2019, 07:07:14 pm
content: In the 70's I was into building Audio stuff and ran across the Direct Conversion receiver concept. One of our local AM radio stations was within range of my function generator so I cobbled up a balanced demodulator and prototyped an AM receiver. The fidelity was remarkably good because the bandwidth was far wider than what the typical AM receivers provided. I had trouble keeping the function generator frequency stable enough so the station's carrier kept coming in. I'll bet something like this could be easily implemented with more modern synthesizers and PLLs.As for FM, I built a transmitter but never tried to build a receiver. Third order intercepts, Smith charts, linear phase filters and the like were more than I wanted to deal with back then. I also started working for real money so I just bought a Marantz tuner and left it at that. The AM wasn't as good as what the direct conversion could do, but I knew that I could never equal the FM. Nowadays, I see there's lots of stuff available to simplify things.Cheers,

author: rdl
author_rank: Super Contributor
timestamp: February 22, 2019, 12:43:39 am
content: Quote from: ebastler on February 21, 2019, 04:57:42 amWhat I'm looking for is a home audio component that would play FLAC and other digital files off an SD card or internal SSD instead of needing a disk, but otherwise be functionally similar to a CD player. About the closest I've seen is the Sony HAP, but it's more of an all in one set up, and stupidly expensive.

author: james_s
author_rank: Super Contributor
timestamp: February 22, 2019, 12:50:52 am
content: I think the traditional component hifi thing went out of style right around the time digital music players became mainstream. Your best bet if you want such a thing is probably to gut an existing tuner, CD player or other component and install the guts of an MP3 player inside it, or just do what I do and plug a portable music player into the receiver and set it on top. The devices exist, just not in the form factor you're wanting.

author: johnkenyon
author_rank: Regular Contributor
timestamp: February 22, 2019, 09:45:03 am
content: Quote from: james_s on February 22, 2019, 12:50:52 amI'm imagining a semi gutted CD player where you press the eject button which operates the CD drawer and also tells the MP3 player to eject/unmount the media.Human being then removes SD card from a slot within the drawer, replaces it, and then closes the drawer.The drawer mechanism limit switch then turns off the tray motor whilst indicating to the MP3 player to mount the newly inserted media.So you end up with a media player which always mounts and unmounts the media correctly, and in theory it should never get corrupted.