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My Sony reel to reel recorder has been idle for many years and on a whim I decided to go through some old tapes and transcribe them to digital format. In the process I use headphones to monitor the audio for quality and content and the recordings sounded very good considering they were recorded from FM broadcasts. Most were recorded from a classical station which did not use compression.
For convenience, I often use my FM transmitter (Ramsey FM 25 A) and Sony Walkman with headphones so I am not tied down with wires. While doing this I noticed a lot of distortion when playing both the original and digitized tapes over FM. They sound good direct but something in the FM system isn’t working as it should.
The editing software I use provides a spectral display and on this I noticed a strong constant peak at 19 kHz in the audio signal. It is hard to believe but the stereo pilot from the original broadcasts apparently was recorded on the tape and when played back through my FM transmitter interfered with the transmitter stereo pilot at the receiver. This was confirmed by applying a 19 kHz software notch filter which eliminated the distortion. This is easily explained but it is surprising since the frequency response of the tape system should not be adequate to record 19 kHz and the record speed was 3 3/4 ips which is less than optimum.
Additionally, the pilot should have been filtered in the receiver but I think I have an explanation. I was using a late ’50s vintage EICO tuner to which I added a homebrew IC based stereo demux. I built this from an application note and apparently the note did not include the audio filtering for the pilot. I was also using a special TDK high output high frequency response tape and the recorder probably boosted the high frequencies to compensate for the low tape speed.
The spectral display also indicated noise extending into the 20 kHz region so I switched to a low pass filter with the corner at 15 kHz to reduce the noise. This worked well.
Strange things can happen in the hobby broadcast world. In this case the audio frequency response was just too good! Nonetheless it is fixed and I am happy with the results.
Neil
Total posts : 45366Hi Neil:
I love the fact that reel-to-reel has come up because I have to face some reel-to-reel problems and you are helping reset my brain. But how about some confusion?
What if the recorder’s bias frequency is part of what’s happening?
For many years we operated a reel-to-reel studio with Tapesonic and ITC decks, but when DAT and digital arrived all the heavy equipment got stored. Now only one deck still runs, except that once the tape is running the “stop” button doesn’t stop it. That calls for contortionism to get it stopped without a rail disaster.
Tapes shedding their oxide is the other problem well worth avoiding.
Total posts : 45366Hi Carl,
Yes, it could have been the bias but the erase/bias oscillator in this recorder operates at about 120 kHz. I have read where some recorders use bias which is just superaudible but this one doesn’t.
The recorder is vintage 1972 and I had some mechanical trouble with it. It has a single knob to control the tape motion functions and it wouldn’t lock into position. The EOT shutoff was stuck. I took it apart and found that the moly grease had hardened on the trip pawl pivot so I cleaned and lubed it and a few other things and the mechanics work as good as new now. The FF and rewind were slow but a cleaning of the belts and pulleys fixed that.
The tapes show no sign of stretching nor oxide flaking and the appearance indicates that the lubrication is still OK. They play just fine. I do have some cheapo tapes I bought in the ’50s which are flaking (Scotch brand 1 mil). They were recorded on an old mono. VM 714 and are not of sufficient quality to transcribe. I still have the VM but it snaps tapes and is not worth restoring. There is one old tape of my HS band in concert with me on first trombone which I may try to digitize and I will probably need to do a thorough head and capstan cleaning afterward.
I still have the splicing tool and splicing tape in my storage bin with the head demagnitizer. I was serious about recording things and maintained the equipment and now it is paying off.
There are people alive today who have never seen a reel to reel machine or eight track cassette and probably would have no idea what we are discussing.
Neil
Total posts : 45366Even Part 15ers who never had tape reels might come upon vintage recordings in need of digitizing, so there’s probably an after-market for the old tape decks. In the same way I hunt for good film projectors because there are films to convert.
My first beloved recorder was a Wollensak, at the time 3M Company owned the brand. It was half-track mono, which allowed tapes to be recorded in both directions. I did an insane upgrade which actually worked, I had a machine shop grind a slip-on capstan to allow the machine to run at 15-ips, and part of the metal cage around the head had to be cut away to make room. This was a little silly since it only handled 7″ reels.
I never liked stereo tape because the phase was hyper-critical and often differed between one machine and another which was devastating on an FM classical music broadcast where the L+R get mixed for mono listeners.
Come to think of it the Wollensak was used at 1630 AM with the Knight kit tube oscillator.
Total posts : 45366Neil, you brought back memories here.
I used to own a Sony TC-377 just like the one in this video.
It had a big rich sound to it and if you connected a mixing board just right to one of these beautiful machines you could introduce a looped stereo echo effect. This was controllable by the tape speed or the way you had it connected to the inputs on the machine.
My machine started to show signs of age several years ago and just before i was about to have it fixed the house we were moving out of was burned to the ground, along with the Sony and over 200 records.
The Sony was not my first Reel to Reel, before that machine came into my posession i had a mono tube type Webcor which had a horrible hum only on the playback. Recordings were clear which was confirmed by taking a sample reel to school for testing on a Tascam.
You sure can’t beat the vintage gear.
Total posts : 45366Barry,
Mine is a TC-366 which is the same as the 377 except for cosmetic changes. Yes, I know about the echo. One of recordings I transcribed was made with the echo effect of my then 3 year old son. He had a ball with the echo on and I laugh outloud listening to that tape. He now has a three year old of his own and I emailed him the recording. I hope he plays it for his kid. It was also fun to put headphones on adults where their speech into the mic was delayed by a fraction of a second with the three head feature. I would ask them to recite Mary Had a Little Lamb and it was fun when they started OK then became confused and began to babble as they heard their voice delayed. Anyone who thinks this is easy should try it.
Sorry to hear about the fire. That is a heartbreaker.
Carl will probably remember staggered head stereo (has nothing to do with imbibing). My VM had that feature for playback only. Carl, your 15 ips story is great! My “invention” with the old VM was to convert it into a dubbing machine. I rigged a second supply and takeup reel belt driven and fed both tapes simultaneously through the capstan/roller with one tape over the playback head and the other over the record head. I kept the tapes routed over the correct head by using a strip of felt between them. It worked great. I also played with video recording by removing the pinch roller and running the tape past the heads at full speed. It didn’t work too well (barely could see a picture) and it is a wonder I didn’t burn the heads with the friction. It was fun to play around with this kind of stuff. I think my mother grayed prematurely as a result of my escapades such as filling the basement with chlorine gas from my electrolysis experiment.
Neil
Total posts : 45366My efforts included leaving a soldering iron plugged in and running out to check my antenna, resulting in a nice burn on her kitchen counter top; putting a long wire antenna for my crystal set up in the back yard that caught birds and nearly electrocuting myself while hacking my slot car track power transformer.
🙂
Total posts : 45366Not much to say here. But I do have a Sony
TC-350 from 1966. It’s one of the greatest
things I have ever owned. I still have it, but
unfortunately, it is not in very good shape from
so many years of getting carted around here and
there and from really heavy use.I absolutely love reel to reel machines! I have a
Akai GX-4000D that is in good condition. At 7.5 IPS,
it does pretty well.Neil, Carl, and rock95seven, I really enjoyed your stories.
And to rock95seven, I’m sorry to hear that you went through
a fire. I’m glad you are OK.Best Wishes,
Bruce, MICRO1690/1700
Total posts : 45366Do any of you guys know of a reliable source
for new reel to reel tape? I have heard it is
still being made. Any ideas would be appreciated.
Bruce, MICRO1690/1700
Total posts : 45366MICRO 1700 for years I bought all tape supplies from avd.com
Audio Video Distributors.
In a quick search just now I don’t see tape on their site, but it’ll be a place to start looking, and they are very friendly and helpful and can probably tell you where to try next.
Total posts : 45366I have a TEAC X-300 reel-to-reel in my Part 15/Internet station as well.
When I was working for a Christian station back in the 80s, I used to make a reel tape of the current CCM songs that I wanted to keep.
Ironically, I bought out that same station’s entire music collection in 2003,
so I have all the original LPs and 45s that I made a living from years ago.(Haven’t figured out how to make a living with Part 15 or Internet radio so far!)
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