Stereo dongles…and stuff

Loved the summary at the end, “they just couldn’t fit it”, LOL

Freaking loved this video. Starts off with a quirky accessory to solve a constraints problem, and then moves on to an excellent breakdown of Stereo/Mono FM. Going to go check my little garage Sony.

I really enjoyed this one.

Really interesting video. I never really thought about it before this, I was under the impression that AM was mono and FM was stereo. I’ve learned something today!

Mine doesn't have FM reception at all

I remember when the BBC were testing out Stereo radion on a Saturday morning. The left channel came out on the TV on BBC2 and the right on the Radio third program which primarily broadcast classical music. A guy would walk accross the room between channels to demonstrate.

I feel soooo deceived to learn now that the Music Centre FM radio I listened to in my childhood may well have been in mono also! I went to great lengths to separate the L and R speakers too, to ensure I got the full stereo experience - or so I thought! No wonder I was so impressed by the stereo output I got when I purchased my first walkman several years later! 😄🎧

I make it a rule, I don't buy a 'smart' phone unless it has a headphone jack. I still use it quite often, even though I have bluetooth earbuds and headphones. When I am working outside, I do not like it when my bluetooth things die so the old fashion wired way is how I roll.

The first “dongle”. We will never be rid of them, it seems!

That was a pretty good opposite/adjacent (tangent). At 5:35, that spherical "Combination Radio / Phonograph" in the catalog looks interesting. I wonder what built-in "light-show" looks like?

Where to begin... I could geek out on FM radio all day. Mono FM is still a thing in some parts of the world. Here in Australia, many low powered FM stations (usually Christian stations) are in mono, presumably because they're nominally limited to either 1W or 10W depending on location, and getting all that fire and brimstone onto the airwaves requires less divine intervention without all that pesky multiplexing science getting in the way. That said, it's not unheard of for higher power FM stations to broadcast in mono; either permanently or for short periods. Horse racing and stations with RPH content (RPH = radio for the print handicapped i.e. an archaic way of saying 'visually impaired') usually broadcast in mono. As for my receivers... the main one I use is in my hi-fi system, and I find myself listening to a couple of community radio stations in FM mono on account of me living in a fringe reception area. I can pick up the stations in question in stereo, but the background noise is just too intrusive. Oddly enough, the noise gets worse when I hook the receiver up to an amplified antenna, even though the signal is stronger. Finally, there is at least one model of OEM VW car stereo with a hidden service menu. In the service menu, it allows the user to see whether an FM station is being picked up in mono or stereo, along with a signal strength meter and a few other interesting things; though the other interesting things are in German so I don't know what they do (I think one of them is related to RDS). I have this particular stereo in my MkI VW Up.

I was looking for a good article to explain how FM stereo works and found this. https://www.radioworld.com/columns-and-views/roots-of-radio/how-fm-stereo-came-to-life And was delighted to see they recommend one of your videos about reel-to-reels.

Had the same sort of thing with a Sony potable radio. The stereo conveter was a lot larger than that unit, it had a headphone amplifier build in as well as line out, it didn’t feedback to the radio. I can’t remember the sony units name apart from it had 55 in big letters on the front

RDS is another interesting thing added to FM broadcast the same way, as it is at the 3rd harmonic of the stereo pilot signal (at 57kHZ) and it's a digital signal. It also recently got an extension called RDS2 in 2015, though I wonder how many stations and receivers are actually using that. RT+ (Radio Text Plus) support seems to be much more universal by now though RDS2 offers much more than that.

Really enjoyed that one!

Keep going on tangents. We appreciate and pay to listen to your fun ramblings. :)

That was a lovely video! Also, is it my impression or your voice has gotten much better in the last two videos or so?

Just went to watch and its removed already :(

I wonder if you were to record the mono FM, then playback with the dongle inline, would it still be able to playback the stereo fm?

Mat, I've recently discovered this cartoon, 'Simon's Cat.' Your hedgehog, cat, and useless chatter experiences make this all the more amusing to me: https://youtu.be/JP1Pk62X7XQ A random funny bit today.

Very much enjoyed, and now aware of another niche audio quirk :) was thinking about the Apple comparison just as you elegantly made the point. As an owner of a few slim profile Apple products over the last few years, I’ve been frustrated with the phenomenon of Dongle-itus when you try to expand the functionality to what some might consider standard port offerings, so fun to know there’s a long stood precedent for this :)

That was a good tangent

What a great rabbit hole! :-) Now then . . . I'd have stuck a meter in the small jack socket on the suitcase radio, found out what the power voltage was the dongle needed, sorted out a suitable power supply with an inline jack socket attached, powered up the dongle and fed it with the mono signal from the new black Sony radio and found out if I could get stereo out of that! Just a thought. :-) Cheers, S.

Great video as always. My immediate thought (and apologies if others have already asked) is wondering if with an appropriate adapter, could you run a pair of speakers from the stereo headphone output on the dongle? I can't recall if the briefcase speakers are permanently wired or not, but with a little tinkering, might it even be possible to play stereo radio out through them via the dongle?

5:30 As ever, getting through Tarleton on Liverpool Road is a pain. West Lancs simply wasn't built for cars.

Good to see it turned up O.K. and still works after all these years.

Across Manchester and the northwest.. :)

I remember some stations being mono in my childhood, but not switching on and off the stereo tone...

We used to turn the stereo pilot tone off on the Manchester Student Radio station because it increased our range and it was the only way we could get down to Fallowfield! Have you had a nice week listening to Ken Bruce?

Regarding the stereo pilot tone, I started listening to Radio 4 comedy shows such as Radio Active in the early 1980s. The news would be in mono, with no stereo indicator. When a stereo programme was broadcast - such as the comedy show - the pilot tone would be switched on, the stereo indicator lit up, and extra hiss would appear! After the comedy, the tone was switched back off again when "The World Tonight" started, and the stereo indicator went out again! One other note, I've got a mid 1990s Matsui FM/AM/SW portable battery radio. it has 1 speaker but also has stereo/mono switch as headphone gives FM stereo.

Thanks Mat, I personally enjoy the wander down the rabbit hole, as sometimes a straight review, whilst being functional, they can be a bit boring, so keep diving down those rabbit holes. Interesting topic, and likely that these days 99.99% of people have taken radio for granted and would assume they are all stereo.

I like your tangents :)

I would imagine you couldn’t just plug any mono radio into the Stereocast dongle and get a stereo output. The radio would have to be able to receive the multiplexed signals. If I’m not mistaken, and I usually am, they used a similar trick to get quadraphonic out of stereo LPs. Perhaps not quite the same, but it used some sort of phase shift and reference tone to multiplex the extra audio.

Your tangent here was definitely related to the subject at hand and gave some insight why Sanyo decided to make FM stereo a separate feature. A nice bonus or sidebar.

I love tangents when they make sense. Fortunately your mind seems to work similarly to mine as to which tangents to follow.

Fancy that. The more things change, the more things stay the same where it comes to dongles... lol

It's a good video and an amusing curiosity here in 2023, but in 1970 whatever I'd have been so upset they didn't even make a little hole for that to fit in that huge box :D

Since the noodle update I've been inspired to try different noodles, so not all in vain! 😁 Quite enjoying the naked noodles brand 👌

My old GE boombox from the mid 1980s has the FM/FM Stereo switch and a L/R balance knob, although with two tiny speakers too close together on the front, it's hard to notice any stereo separation, but at least it still works.

Somewhere I've read/heard that car stereos introduce the FM stereo difference signal gradually according to the received signal strength - getting the best of both worlds, with the audio as clear as possible with no channel separation at all in the fringe areas, full stereo with strong signals, a bit of stereo in between and all that with no obvious switching (what home hifis set on stereo/auto do when the signal intensity crosses the threshold for stereo). The mono switch is not that useful then. I'm quite sure my car stereo does this, but I can't find any details on it online.

"Dongle" sounds like an insider insult. Only a berk would need to buy a dongle. Well Edison, I don't quite feel like shelling out over the odds for your dorky looking ear pods. I'll buy a hearing aid when I'm good and ready.

Ugh, thank you for being as annoyed by the iPhone mandatory headphone dongle! Among other things, they aren't built to last and they "go potty" (as ya'll say!) after only a few weeks. Whenever I get a replacement I am sure to get a spare because they are constantly falling out of pockets or being left on car seats. I so resent "forced purchases" from these companies.

I loved this episode, Matt. I'm curious about how much mono FM broadcasting occurred durin the early years of FM radio. I'd also would be interested in learning more about the AFC (Automatic Frequency Control) which used to appear next to FM buttons on early AM/FM radio tuners.

I had a similar "ah ha" moment with FM stereo. I recall growing up (late 70s, early 80s) and some consumer stereos having a separate switch for "FM Stereo". I suppose I never thought much about it at the the time. I might have thought that "stereo" was the same as a "boost" (as in "bass boost", so popular with car stereos in my high school days for when you want people to know you owned a Run DMC cassette).

I'd be tempted to feed the output of the Stereocast back into the stereo mic inputs on the music centre, via a dual mono adapter cable, to listen and record in stereo. Might be a bit distorted. Also I get the impression you had to wait around a bit for Greatest Hits to stop playing copyrighted music, do you still have an FM transmitter? I have my old Belkin one and have bought two more for cars in the last year, they're actually very good and just so simple to use.

Before I read Duncan's posts in the community I had no thought to question whether an FM-capable device was stereo output, as long as there were stereo speakers. I have an ICF-34 - and even though it only has one speaker I thought the headphone output was FM stereo due to a right/left headphone output... it sounds fine. Perhaps my perception arises from old AM transistor radios that were equipped with a single-ear headphone pod. Today I know my logic was flawed; especially the more I think back it all makes sense now. Your videos are always thought-provoking to me; they pass along both helpful and entertaining information.

FM receivers in cars usually have a built in feature which automatically switches the reception to mono when the signal is weak. Lots of times I'm driving and I can hear the audio collapse down to mono during music.

Now I really wish there was an easy FM mono button on my car radio! Sorry if this sounds dumb, but does that mean on your white mono radio with the stereo out, it is sending the original unmodulated broadcast signal to the internal mono speaker and only demodulating en route to the headphone jack? Or is it demodulating everything and the internal speaker is just wired up to both left and right? ie: is it taking advantage of the stronger mono signal when listening to the internal speaker.

Did you consider plugging the Sanyo dongle to the Sony mono radio, just powering it from the Sanyo? Could be a fun thing to validate your hypothesis that it would work.

Go off on tangent whenever you want, it's one of the things which make your videos so enjoyable.

I had a bit of a mind -blown moment. My experience with Radio 4 on the radio has been in longwave, as I was listening in Europe. Susan Calman talking about family holding grudges...in STEREO...seems weird. I guess maybe they use it for The Archers and drama features? Do the English go around and listen to Just A Minute in STEREO? What in the world?! Give me that sweet shipping forecast in 5.1 surround sound baby! By the time I moved to the USA I was listening on the internet and I haven't noticed it being in stereo. I usually listen with one headphone in. Maybe the digital stuff isn't stereo? Now, on FM stereo: My car does have an FM Mono feature I turn on during road trips so I can get decent stations for longer. It almost definitely is buried in your car settings. It may be placebo, as the car is fairly new, and I don't notice much of a reception penalty on modern DSP radios. I have found my pocket radios with switchable stereo and mono FM have only a very small penalty in reception if they're DSP. DSP radios do some kind of magic with FM Reception and I am too dumb to know why. The only time I use it is when going to baseball games and listening at the baseball game. For some reason it comes in better as mono there. I assume it's other interference at an MPX type bandwidth. Vwestlife might know a lot more about this type of thing. He has a stereo AM pirate station, so he's gotta be well versed.

Now you've got me wondering how the mono signal becomes stereo.

Got me wondering now about my earliest surviving self-made cassette recording from the radio, the Top 20 from April 1986, made when I was eight! I'll have recorded it on my single speaker Phillips radio/cassette recorder from when Radio 1 took over Radio 2's frequency for the charts on a Sunday night, but it has a terrible hiss, and it was certainly in tune. Must dig the tape out and have another listen. Of course I still have it! Oh, Cliff Richard and The Young Ones were at No 1 with Living Doll, if you're interested!

That's kind of fascinating. The fact that it works at all means that the mono receiver is not filtering audio above about 15kHz, which allows the 38kHz subcarrier to be passed through to the audio output, and then decoded later by the Stereocast. In theory, this degrades the quality of the audio if you don't have the Stereocast connected, but I guess the quality of audio hardware of the period wasn't good enough to be able to tell. You probably couldn't connect the Stereocast to modern mono receivers, as they all should filter out the 38kHz subcarrier from the audio output. (Incidentally, this is related to the MPX filter on some cassette decks, which remove the signal that lights up the Stereo light on your radio. Doing so improves the quality of the recording, while retaining the stereo audio.)

Ha I was wondering if you'd mention DAB and being mono a lot of the time! FM often sounds better than DAB due to this...

Entertaining and informative video as always, you should get it sponsored by GHR!

I have never heard of FM not being stereo before this.

Mmmm tangents

Will watch now. I just wanted to say that I found the cup of noodles to be fascinating listening in the car.

Tangents are good. Hope you and yours are doing well.