Tascam 424 mki fast playback

[skywaveTDR]

One more question, is a frequency counter and a wow and flutter meter the same thing? I think I started using them interchangeably by mistake.

Thanks!

Well yes and no. Some parts do the same and other have no ability to show you anything. The frequency counter shows you a digital readout of the frequency of the signal and it counts the amount of events within a precise 1 second setting. This means Cycles per second or Hertz. It can not tell you anything about the wow and flutter figures.
The LFM39A specifically shows the tape speed as a drift amount away from the precise internal crystal clock 3000Hz or 3150Hz depending on the settings.
A good machine should give a drift that sits at the center position which is exactly 3KHz.

What a wow and flutter machine can tell you even more is the condition of the transport- does the wow appear to be cyclic then it could be burned out fields in a reel motor. If there is high wow and flutter beyond normal then you may have tension or bearing problems. In finding out about the AMSoil I use which is a synthetic, I had observed a great amount of decrease in the wow and flutter of a deck. Some that measured .055% when after oiling measured .025%. People ask me why I press on to tell people to use this oil as expensive as it is. Well look at the numbers. No other oil- Triflow, Zoom Spout or others do this. When sliding a capstan shaft back into a bearing the human hand can tell right away what is happening as it feels smooth as silk. Now I have had amateurs send in decks that the thrust play was taken out and it was tight- wow and flutter goes through the roof. These people do not ask nor know what they are doing- these are the most of the E bay people selling you a deck.

 

[skywaveTDR]

Ohhh ok. That makes much more sense. Let me see if I can sum it all up again and let me know if I'm understanding correctly. I have one more question, but I want to ask that after me restating everthing:

I need a:
- Service manual
- MTT111 tape recorded at 3Khz
- Frequency Counter
- Wow and Flutter Meter
(From what I read on the A.N.T. audio, it looks like he combined the Frequency Counter and Wow and Flutter meter. So that's a 2 for 1.)

And that question is, if I start working on my Tascam 424 while it's plugged in, that's pretty hazardous. So would you happen to know of any gloves that would protect me from injury? I think the unit is about 240V AC.

What you need as all Technicians need is a thinking brain. The only danger as with even open reel decks is where the power cable goes in and is put to the power switch. You can use a thick glove made to withstand 240Vac like the linesmen use but I think you will not get much work done that way. I don't work on 240V equipment because here in Chicago area it is 120Vac. In 47 years I have been stung and it is just a lesson to learn to keep your hands off of there. I did work on Transmitters that had 10KV plate voltage so when you know of this the brain tells you to stay a good distance away from there. That is why these Transmitters have interlocks that shut down the power when a cabinet is opened.
If you are the nervous type you can cut a piece of plastic tubing that can be fixed around the power section with a silicon glue to protect hands if working in that area but then a good precaution is to keep your hands 3-4" away from those exposed terminals. Heat shrink can also be put on exposed circuits but I think you can go crazy on this stuff. Just be careful is all you need to do. The high voltage only exists around the power switch and then going up to the transformer and this can include fuse boards if they are used. Some capstan motors get 100Vac applied to them but that is not done in cassette decks. They are mainly 12Vdc.

 

[A. Lacy]

Well yes and no. Some parts do the same and other have no ability to show you anything. The frequency counter shows you a digital readout of the frequency of the signal and it counts the amount of events within a precise 1 second setting. This means Cycles per second or Hertz. It can not tell you anything about the wow and flutter figures.
The LFM39A specifically shows the tape speed as a drift amount away from the precise internal crystal clock 3000Hz or 3150Hz depending on the settings.
A good machine should give a drift that sits at the center position which is exactly 3KHz.

What a wow and flutter machine can tell you even more is the condition of the transport- does the wow appear to be cyclic then it could be burned out fields in a reel motor. If there is high wow and flutter beyond normal then you may have tension or bearing problems. In finding out about the AMSoil I use which is a synthetic, I had observed a great amount of decrease in the wow and flutter of a deck. Some that measured .055% when after oiling measured .025%. People ask me why I press on to tell people to use this oil as expensive as it is. Well look at the numbers. No other oil- Triflow, Zoom Spout or others do this. When sliding a capstan shaft back into a bearing the human hand can tell right away what is happening as it feels smooth as silk. Now I have had amateurs send in decks that the thrust play was taken out and it was tight- wow and flutter goes through the roof. These people do not ask nor know what they are doing- these are the most of the E bay people selling you a deck.

Oh ok that makes sense. Yeah I think I understand the difference between Wow and Flutter Meter and a Frequency Counter. The Wow and Flutter measures the bearings and and belts and the motor. The Frequency measures the overall record/playback speed of the machine. Is that correct?

 

[A. Lacy]

What you need as all Technicians need is a thinking brain. The only danger as with even open reel decks is where the power cable goes in and is put to the power switch. You can use a thick glove made to withstand 240Vac like the linesmen use but I think you will not get much work done that way. I don't work on 240V equipment because here in Chicago area it is 120Vac. In 47 years I have been stung and it is just a lesson to learn to keep your hands off of there. I did work on Transmitters that had 10KV plate voltage so when you know of this the brain tells you to stay a good distance away from there. That is why these Transmitters have interlocks that shut down the power when a cabinet is opened.
If you are the nervous type you can cut a piece of plastic tubing that can be fixed around the power section with a silicon glue to protect hands if working in that area but then a good precaution is to keep your hands 3-4" away from those exposed terminals. Heat shrink can also be put on exposed circuits but I think you can go crazy on this stuff. Just be careful is all you need to do. The high voltage only exists around the power switch and then going up to the transformer and this can include fuse boards if they are used. Some capstan motors get 100Vac applied to them but that is not done in cassette decks. They are mainly 12Vdc.

Ok awesome. That's pretty reassuring. I was thinking about getting some big linesman gloves, but I think I have some work gloves that should do the trick if I get nervous. Thank you so much for all of your help. Is there anything else you think I should know before I start going to work on my Tascam 424?

 

[A. Lacy]

I've found another question yet again. I posted the link of those correction tapes on GennLabs, but I did some more research and found there are some speed alignment and tape callibration tapes on eBay for much cheaper. Do you think these would work?

Cassette speed calibration & head alignment tape 1000 Hz, 3000 Hz, 7000 Hz | eBay

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And if not, where do you get your speed alignment tapes from?

Thanks again for all of the information!!

 

[skywaveTDR]

The speed alignment tape is made pretty easy on a known just calibrated machine. It will contain 3KHz sine wave and I make my secondary one at 0 Vu.
Those tapes that suppose to be of azimuth and levels are not accurate as that takes a lot more machine to make them right as in a full track width reel deck.
There was a guy selling speed tapes for about $7.00 on E nay some time back just for speed. Where levels and azimuth are concerned a regular tape deck will not make those right and those that try and make them this way are clearly not knowing this.
My speed tapes are actual Teac MTT111 and MXT111 tapes from the Chicago Factory Service when they closed down plus I may have bought some when I worked there. I spent time on the bench ther under two different owners from 1982 to 1999 or maybe 2000.

 

[dkokalanov]

Well yes and no. Some parts do the same and other have no ability to show you anything. The frequency counter shows you a digital readout of the frequency of the signal and it counts the amount of events within a precise 1 second setting. This means Cycles per second or Hertz. It can not tell you anything about the wow and flutter figures.
The LFM39A specifically shows the tape speed as a drift amount away from the precise internal crystal clock 3000Hz or 3150Hz depending on the settings.
A good machine should give a drift that sits at the center position which is exactly 3KHz.

What a wow and flutter machine can tell you even more is the condition of the transport- does the wow appear to be cyclic then it could be burned out fields in a reel motor. If there is high wow and flutter beyond normal then you may have tension or bearing problems. In finding out about the AMSoil I use which is a synthetic, I had observed a great amount of decrease in the wow and flutter of a deck. Some that measured .055% when after oiling measured .025%. People ask me why I press on to tell people to use this oil as expensive as it is. Well look at the numbers. No other oil- Triflow, Zoom Spout or others do this. When sliding a capstan shaft back into a bearing the human hand can tell right away what is happening as it feels smooth as silk. Now I have had amateurs send in decks that the thrust play was taken out and it was tight- wow and flutter goes through the roof. These people do not ask nor know what they are doing- these are the most of the E bay people selling you a deck.

Nice information! Could you share the exact AMSoil type? Is it specific for audio gear or did you use engine one?