Showing posts with label tuners. Show all posts
Showing posts with label tuners. Show all posts

Thursday, October 26, 2017

How'd we stereo on radio before there was stereo radio?


The era of FM stereo radio began in June 1961, but the era of hi-fi stereo radio dates back to the 1950s.

But in the days before FM multiplex broadcasting, listening to stereo radio required two stations . . . and two radios, one AM and one FM. Or you could just buy a "binaural" AM-FM stereo tuner -- two dials, two tuning knobs, and in stereo mode, it would play AM and FM at the same time.

AM was on the left, FM on the right. (Unless, of course, it was the other way around. Or a complete free-for-all?)
 

What in the world would that have sounded like in, for instance, 1958? Let's take what we know about the capabilities of AM broadcasting and FM stations in the '50s, then see whether we can re-create the binaural AM-FM stereo experience.

It's November 1958. You're in Baton Rouge, La. It's 9 p.m. on a weeknight (Monday through Thursday), and you're in the mood to hear some WJBO "3-D" stereophonic sound on your new hi-fi setup.


ON YOUR NEW binaural high-fidelity tuner, your tune in 1150 on the AM dial. Left channel, check.

On the FM dial at 98.1 megacycles, you tune in WJBO's sister station, WBRL. Right channel, check.

Now it's time to sit back, relax and experience "music in three dimensions." For those of us back here in the future, the result sounds better than you would think.

Then again, so did AM radio in 1958. It's amazing what could be done with a wider AM bandwidth, owners who cared and well-engineered radios in listeners' homes.

I HOPE the following video demonstrates that, as I try to re-create what the WJBO-WBRL, AM-FM stereo pairing might have sounded like. I can't tell you how many times I redid this, trying to get the AM sound "right" . . . AM heard over excellent equipment, much better than what we're accustomed to today, from an era decades past.




I KEPT redoing this because I kept thinking, "No. This sounds too good. This can't be right."

And I kept saying this as someone who has a couple of AM-FM hi-fi tuners made in 1960 and knows that some amplitude-modulated stations, to this day, sound pretty decent on a true wideband tuner. This, despite the Federal Communications Commission -- in order to lessen interference and shoehorn more stations onto the dial three decades ago -- putting brick-wall limits on AM stations' frequency response out of the transmitter at 10 kHz.

A young person with good hearing can perceive frequencies up to 20 kHz.
 


But in 1958, many AM stations' transmitters had a frequency response almost as good as FM stations. FM's big advantage was in improved dynamic range, a lower noise floor and, as Steely Dan sang, "No static, no static at all."

Below is a rough representation of the frequency response of the "AM side" -- the left channel -- of the video above.


YOU'LL NOTE that I rolled off the low frequencies, just like a typical AM signal, then sharply rolled off the high end right below 15 kHz. I also bumped up the equalizer curve here and there to "sweeten" the sound a little, as an engineer would have done with even the rudimentary audio processing of the day. I tried not to overdo it. After all, I was worried that it sounded too good; I still wonder what I missed.

Too, the AM channel is more processed -- more compressed and a bit "louder" -- than the FM track. The reason? The easy answer is "That's what AM does."

The longer answer involves an attempt to, first, mimic the lesser dynamic range of AM broadcasting and, second, reflect that AM stations were much more heavily compressed and "hard-limited," because loudness equals distance and listenability on the noisy AM band.

Oh . . . I also added some "AM noise" to the "AM side" of the recording. Not too much, I hope, and not too little, either.

On the "FM side" of the soundtrack, I frankly worry that the audio may be too processed. Alternatively, however, if I were a chief engineer or a program director in 1958 and my AM-FM combo was going to dive into the "binaural stereo" thing . . . I'd want the FM side to match the AM side at least somewhat for loudness.

THAT'S IT for the technical and audio-geek minutiae. I doubt a normal person could stand much more.

Even if you're not a full-bore nerd like me, I hope you've still found a little fascination in this esoteric inquiry into one of the more forgotten aspects of hi-fi and broadcasting.

A phenomenon that births advertising like this (from 1959, after WBRL had changed call letters to WJBO-FM) -- not to mention a moniker like Soundascope Radio -- can't have been a total bust.


Monday, December 22, 2014

Merry Christmas from your local radio geek


Welcome to FM radio as it looked in 1947.

This is a vintage Pilotuner FM tuner, made by the Pilot Radio Corp., of Long Island City, N.Y. Back in the day, you'd hook this up to the phono input of your existing "standard" radio or console to enjoy the exciting full-fidelity world of frequency modulation broadcasting.

As such this vintage Model T-601 might be called the granddaddy of hi-fi tuners for your sound system. And some 67 years on, it doesn't sound bad -- in glorious monophonic sound with none of the bells and whistles of modern FM gear, but not bad at all considering.
  
SO . . . if this awakens your inner audio geek, here's a video of my mono hi-fi setup -- an 1957-vintage Realistic FM tuner and amplifier pair, along with a Zenith stereo record changer (outfitted with a modern magnetic cartridge) which has seen better days and likely will be replaced soon . . . and the vintage 1947 Pilotuner I just found via eBay. The Pilotuner is what's playing here, with only a length of wire for an antenna.

The speaker , which you've seen (and heard) before here on the blog is a newly built Gough speaker enclosure from the original 1960 plans and outfitted with a 1962-ish Electro-Voice "Wolverine" 8-inch triaxial driver.

Eventually, the Pilotuner will live in our bedroom, paired with a 1951 (or thereabouts) Bell amp and a 12-inch Electro-Voice Wolverine speaker kludged into a vintage Wharfedale speaker cabinet.

No, my geekery knows no bounds. I have a loving and tolerant wife, thanks be to God.

Wednesday, March 05, 2014

Old-school high fidelity geekery


The speaker: A mid-'60s Electro-Voice "Wolverine" 8-inch, full-range driver in a new Gough speaker enclosure built by a friend who has a custom furniture business from the original 1960 plans sold by Jabez Gough of Cardiff, Wales.

https://books.google.com/books?id=VSEDAAAAMBAJ&lpg=PA168&dq=popular+science+nov.+1961+gough&pg=PA168&hl=en#v=onepage&q&f=false
The hi-fi: A 1956-57 Realistic amplifier and FM tuner. The glory of vacuum tubes!

The result: Pretty dadgum amazing . . . and all in glorious monophonic sound, being that stereo was awfully new-fangled in 1957.

Now, what you can't feel is the floor shaking -- all from a 10-watt tube amp. What you can see is that our house is undergoing a never-ending remodeling. This dining room here is due for a new floor next week . . . then on to the painting and whatever else.

I'm sure there will be "whatever else."

Thursday, February 20, 2014

Party like it's 1959


This is your audio-geek moment for Thursday, Feb. 20, 2014. Today, we'll party like it's 1959.

Above, the 12-inch, Electro-Voice full-range speaker of -- more or less -- that vintage. I got it via eBay, the best Internet friend of vintage-audio geeks like yours truly. The last part of the previous sentence, I suppose, also could be written sans hyphen and be just as accurate.

Anyway, this "Wolverine" driver from the venerable company is what folks bought when they embarked upon building themselves a "hi-fi" speaker. Basically, it's a woofer, mid-range and tweeter all in one.

Folks back then often got fancy and added a "crossover" and separate mid-ranges and tweeters just like what prevails today, but I'm lazy. Besides, a speaker enclosure with just a good  full-range "coaxial" or "triaxial" speaker was pretty common back then.

Combine something like that with a vacuum-tube amplifier, and that's what you call "vintage sound." I do love me some vintage sound -- probably because I'm a vintage audio geek. No hyphen.

BUT TO GET a vintage speaker for my vintage tuner and vintage amp, I needed an equally vintage cabinet. One, it must be noted, that wouldn't permanently disfigure our checking account. (You'd be surprised at how much a nice, half-century old hi-fi speaker can monetarily disfigure.)

Hello, eBay!

And hello to a Wharfedale W-60 speaker cabinet that's about the same age I am, sans guts. Or a woofer and tweeter, to be technical about it. Fifteen bucks . . . plus some rejuvenating oil, a black marker, a little wood stain and some elbow grease, which turned scuffs and worn-away veneer into gorgeous "character."

Of course, with old speaker enclosures like this, the only thing that's meant to come off is the back. That's bad when the screws that hold the speaker in are too short . . . and in the wrong places for the new-old Wolverine you bought to go in that box.

I had to do something that wasn't pretty . . . but it worked. And nobody will see it, so who cares?

Breakage of particle board and application of duct tape may have been involved.

Is what I am saying. Don't judge me.
AND VOILA! The finished product, voicer of "vintage sound" from my vintage hi-fi setup.

I think it's happy. See?

Wednesday, June 05, 2013

Analog in a digital world


Rockin' it really old school in the Revolution 21-slash-3 Chords & the Truth studio tonight. Jazz in the night from a 1960 Voice of Music tuner hooked up to a 1962 Pioneer stereo multiplex converter, and it's all being recorded by a TEAC reel-to-reel deck, circa 1969.

The Crown monitor amp is new, but what you gonna do? They're damn fine amplifiers.


For what it's worth, I shot the video with a Microsoft Surface tablet, which has decent-sounding microphones that also are prone to being overdriven. Sorry about that.

Friday, April 19, 2013

Because I'm a geek . . .


. . . I get all excited about procuring a 1962 Pioneer FM multiplex stereo adapter to go along with my monophonic 1960 Voice of Music tuner.

I did have a pretty basic V-M multiplexer hooked up to it, but the Pioneer is sooooo much nicer. And better. And you can adjust the stereo separation -- cool!

I just lost you, didn't I? My wife's eyes glaze over at "FM stereo multiplexer."

But she did perk up  at ". . . and I got in on ebay for about $150 less than these things usually sell for."

Tuesday, July 10, 2012

Midcentury mesmerized


This little Realistic vacuum-tube FM tuner, circa 1956 and manufactured for Radio Shack by Harman-Kardon, kicks serious audio booty.

Fifty-six years old. Monophonic -- in '56, there was no FM multiplex stereo yet. And it sounds like a little bit of heaven. It's just stunning when you get a strong signal into it, particularly on classical music.

The less overprocessed the station's audio is, the better . . . but 56 years ago, that really wasn't a problem, was it? The FM "loudness wars" still were decades away.

I plugged this little gem -- the first to bear the "Realistic" brand -- into my Soundcraft mixer in the Revolution 21 studio, and I'm running it through a Crown D-75A amplifier for now. It really is amazing; the sound just jumps from my Electro-Voice studio monitor speakers.

I'M KIND OF afraid to hook this mono mini (it really is very small) up to the stereo multiplexer -- it might never leave the studio if I do, as opposed to what I have planned for it.

Think I'm exaggerating? Here's a 44-minute MP3 of the thing tuned into the local classical and classic-rock stations. Dear God.

I ALSO got the matching Realistic five-tube, 10-watt amplifier (manufactured by Grommes), which is a real beauty. See?

I've yet to hook that up -- eventually, the Realistic tuner will be paired with it to make a complete 1950s hi-fi system.

If anyone would like to donate a vintage 1956 hi-fi floor speaker. . . .

For now, I'm "making do" with an early-1970s University Sound floor speaker. (Note ironic quote marks. Nothing about a vintage University floor speaker constitutes "making do.")

You'll note the tuner and amp say "Radio Shack Boston." In 1956, there was one Radio Shack, and it was in Boston.

This concludes Your Daily Geek for Tuesday, July 10, 2012. Live long and prosper.

Monday, July 02, 2012

The sound of the '60s


This is an average hi-fi tuner from 1960.

Behold the Voice of Music Model 1416, a nine-tube AM-FM-FM multiplex tuner in all its midcentury-modern glory. This one is hooked up to a V-M multiplex adapter to allow it to receive stereo broadcasts.

And here is what an average hi-fidelity tuner sounded like in 1960. Starting in the fall of 1961, this is what one sounded like when tuned into an FM-stereo broadcast.

Really? You haven't figured out that I'm a major-league gearhead by now? Consider yourself informed. Yes, it is an addiction.

But a fun one.

As I was saying. . . .

What you'll hear here is some of a Saturday-night jazz program on KIOS, one of Omaha's public-radio stations. Enjoy!