Rebuilding a Pioneer CT-F900 Transport

I don't have access to an open unit at this time. The interconnect diagram, and the motherboard foil pattern drawing are in conflict. In the front, left corner of the motherboard is a pin, labelled 2A. Look straight back from there to the center of that side of the motherboard, and you will see a pin labelled 1A. Whichever of those that does not have a wire connector on it is likely where your wire goes. The other pin will connect to to another tab on the same micro-switch.

Report back, so I can correct my service manual.

Enjoy,
Rich P
Yes (2A) does not have a wire, (1A and 1B have the white and black wires) I appreciate your help. I have seen many circuit boards with extra pins so I'm glad to know for sure. Thanks again.
 
Hi Rich.
I am planning to rebuild my pioneer CT-F900 transport but I don't see grounding wire on mine including the one near the captain wheel? Do you think my version did not have one? If there I don't have it, can you please let me know what issue should I have without it?
Please let me know. Thank you.
 
Hi Rich.
I am planning to rebuild my pioneer CT-F900 transport but I don't see grounding wire on mine including the one near the captain wheel? Do you think my version did not have one? If there I don't have it, can you please let me know what issue should I have without it?
Please let me know. Thank you.
The transport ground connection is a formed length of spring steel, serving to connect the metal parts on the front to the metal parts on the back of the transport. This was necessary because the transport main parts are plastic. If someone replaced the belts back in some part of your deck's history, the tech may not have noticed the connection, and it could have fallen down inside the deck, or been crammed in the transport some way, or may have been removed and discarded. The service manual does not show the grounding spring for the CT-F900, but the CT-F950 does show it. Maybe early CT-F900s did not have it, but later ones definitely did.

What you could get without the grounding wire is a bit of hum, or a bit of extra motor noise, during playback, recording or both.

One thing to note, is that this model will exhibit a bit of extra hum and noise when the metal cabinet top is not installed. So don't be misled there. If the unit is nice and quiet with the top installed, You might get away with the ground connection missing.

Good luck,
Rich P
 
The transport ground connection is a formed length of spring steel, serving to connect the metal parts on the front to the metal parts on the back of the transport. This was necessary because the transport main parts are plastic. If someone replaced the belts back in some part of your deck's history, the tech may not have noticed the connection, and it could have fallen down inside the deck, or been crammed in the transport some way, or may have been removed and discarded. The service manual does not show the grounding spring for the CT-F900, but the CT-F950 does show it. Maybe early CT-F900s did not have it, but later ones definitely did.

What you could get without the grounding wire is a bit of hum, or a bit of extra motor noise, during playback, recording or both.

One thing to note, is that this model will exhibit a bit of extra hum and noise when the metal cabinet top is not installed. So don't be misled there. If the unit is nice and quiet with the top installed, You might get away with the ground connection missing.

Good luck,
Rich P

Thank you Rich. I am really appreciate it. The unit is in very nice shape. I just replace all belts and lubricate them according to your instruction. The issue I have now is: After replace all the belt (no spin roller or spin idler) , the wow and flutter are noticeable. In another word, the sound of violin within the music seems distortion. It seems like the spin roller or something not right cause the movement on the tape. I don't know what I should do.
Do you think because of the new belt? I order belt kit from WJOE. The belt width seems smaller than the original one. Can you please help? Thank you
 
I don't know. I can't tell from here. Maybe a belt is riding on the side of its pulley instead of in the middle. Maybe the unit did not get reassemble properly, or a part is damaged, one more pinch rollers is not good. These transports are delicate and sensitive to things incorrect.

Good luck,
Rich P
 
Can You tell me, where is located a playback speed calibration potentiometer in CT-F900. I cant find any information in service manual, how to do it.
 
Other than being unable to spell "decrease", my copy of the service manual spells it out pretty well...

:D

Good Luck!

SpeedAdjustment.jpeg
 
Thanks Rich, with your guidance I was able to do my ct-f950 with great success! I'm listening to the BEE GEES GOLD right now! IMAG0571.jpg
 
Excellent write-up! I picked up a CT-F900 not too long ago and have the problem many people speak of - take up reel stopping during playback. Tore deck apart per your excellent instructions and am down to where I can remove the belts, idler, etc. You mention replacing the entire idler instead of just the tire saying that "it is still available". I can find the belts, but cannot find either the idler tire or the idler. Does anybody have a source they can point me to for these parts? Thanks!! John.
 
Wouldn't you know it, after I made my last post asking for sources for the idler tire, I was able to find one. I found it at http://www.wjoe.com/vintageandantiques.htm. His kit contains the belts and the idler tire, so that is out of the way. But, still, if anybody knows of a source for the idler itself, please let me know. I may as well replace it as long as I am in here :) Thanks! John.
 
Pioneer has pretty much dropped the spare parts for vintage gear business. The tire is likely where it will end here, unless you NEED the idler. Then you will need a part from a parts unit.

Rich P
 
Pioneer has pretty much dropped the spare parts for vintage gear business. The tire is likely where it will end here, unless you NEED the idler. Then you will need a part from a parts unit.

Rich P
Thanks for the quick reply Rich - I appreciate it. And thanks again for these excellent instructions for rebuilding the transport! Hopefully I will get everything put back together correctly once I receive the belts and tire :) Have a great day!! John.
 
I have no current plans to generate cassette deck calibration thread, because each deck, not each model, each deck, presents individual challenges to the calibrator. Tape deck calibration, for cassette decks in particular, is not a DIY operation.

Detailed technical knowledge of magnetic recording principles is required.

A good tome containing the basics is "Techniques of Magnetic Recording," by Joel Tall (1958). It is an old book, but the principles are still sound.​

Understanding bias is critical, as proper equalization is impossible without it. Refer to "Biasing in Magnetic Tape Recording," by John McKnight of Ampex Corp. (1967), and "Bias," by Terence O'Kelly (date unknown, from the BASF "The Inventor's Notebook, Technical Bulletin #3."

All of this knowledge is in addition to the technician's knowledge of general electronics, which is covered fairly well in "The Art of Electronics," by Paul Horowitz And Winfield Hill (2001).​

"Calibration" means to adjust deck performance (play, record, Dolby) to specified requirements, while maintaining traceability to fixed industry standards.

If the traceabilty is not involved, a deck can be calibrated to perform somewhat well in isolation, but tapes made on other machines will sound bad, or tapes made on the single machine will sound bad on other machines.​

Proper calibration begins with playback calibration steps requiring special test tapes that are calibrated to industry standards. Record calibration then works with specified input levels from signal generators, built upon adjustments made during playback calibration. If you do not have those calibration tapes, you should not attempt a DIY calibration.

You cannot make your own test tapes, without access to linkage to verification to the standards (tape speed, flux density, frequency response, azimuth alignment, etc.), and without access to special recording equipment.

There are test tapes flowing into the country from China, via Ebay. I am very dubious as to quality and traceability, since China is into so much counterfeit production. One day I will pick up a tape or two and see how they compare to verified tapes. Until then, I do not recommend using such Chinese tapes for calibration. There is a member of tapeheads.com that also represents himself as a source for calibration tapes, but I have not tried any of his either.​

Here is a list of calibration tapes that I have, and require, to perform cassette deck calibration:
  • Mirror Cassette (Sony MC-109C) - Used to visualize passage of tape through the transport, and across the various rollers, guides, and heads.
  • Torque Meter Cassette (Teac (MTT-8111 and Sony TW-2422) - For measuring reel torques.
  • Wow & Flutter / Speed Cassette (Teac MTT-111N) - To set tape speed and to measure transport performance.
  • Azimuth Level Cassette (Teac MTT-255 and/or MTT255C or MTT-114N) - To provide for the adjustment of fine azimuth relationship between tape and playback heads.
  • Dolby Level Calibration Tone Cassette (Teac MTT-150) - To set playback levels required for proper interaction with Dolby circuitry, as well as playback level and meter representation.
  • 315Hz Level Cassette (Teac MTT-212N) - For proper base line playback levels, and foundation for equalization adjustments.
  • Calibration / Frequency Response Cassette (ABEX TCC-162) - For overall performance verification, Dolby playback and frequency response adjustment, at levels appropriate to vintage Pioneer cassette decks (freq. response is at -20db).
You will also need quality, lightly used or fresh blank cassettes of all four tape types addressed by vintage Pioneer cassette decks. This is what your decks will be calibrated to. There was light enough variability between tapes of specified types, by various manufacturers that a deck calibrated to one manufacturer's tapes will perform well with others. The exception is metal tape, where there was a pretty wide performance spectrum. There you will have to choose one and run with it. Here is what I calibrate to:
  • Standard Bias: TDK D90
  • High Bias: Maxell XLII
  • FeCr: Sony Duad
  • Metal: Teac MDX (Maxell MX-S tends to be a bit too hot (coercivity too high) for vintage Pioneer decks)
Like AM/FM/Stereo tuner calibration, tape deck calibration is some of the most complicated and requires specialized equipment to perform.

Such equipment must be, itself, properly calibrated to industry standards. Also, such equipment is generally no longer manufactured (to my knowledge). Attempting to perform tape calibration without the special test equipment is very cumbersome, if not impossible, in some stages.

You need signal generators and milli-voltmeters, calibrated to dbV, with proper loading, to properly set levels and frequency response, unless you know how to create proper loads and do the proper math conversions.​

Here is a list of test equipment that I have, and require, to perform tape deck calibration:
  • Leader LMV-185A 2-Channel AC Millivoltmeter - I use two of these, one to measure stimuli and one to measure response (input vs. output). This means that frequently, I am measuring 4 test points simultaneously. This meter is calibrated in the required units, dbV.
  • Leader LFM-39A Wow & Flutter Meter - To measure transport stability and speed.
  • HP 8903A Audio Analyzer - To provide for proper adjustments referencing distortion.
  • Sound Technology 1700B Distortion Measurement System - To provide for proper adjustments referencing distortion.
  • Leader LAG-126S Audio Signal Generator - To provide proper stimulus tones at required levels and loading. This generator is calibrated in the required units, dbV.
  • Fluke 8060A True RMS Multi-meter - I use two of these at a time, in places, to provide various internal measurements and comparisons (voltage, frequency, relative voltage, etc.)
Calibration to the varying tape types presents many difficulties, since the various adjustments are interactive between tape types, and with other calibration adjustments.

Here is where the experience, skill, and art come into play.

Knowledge of how the mechanical elements of the transport affect calibration and performance is also, generally, gained by significant experience.

Disregard this statement to the peril of your gear. You could easily wind up with pretty vintage paperweights.​

Bottom Line:

Remember that you have been warned. Cassette decks with botched calibrations are especially unpleasing. The compact cassette was not originally designed for HiFi reproduction. Rather, it was designed for dictation machines. HiFi designers successfully pushed the envelope, and were able to squeeze serious performance from this medium. However, since most performance characteristics are pushed to the boundary for the medium, any divergence from correct is readily apparent (wow and flutter, tape path stability, head azimuth, bias settings, equalization curves, Dolby curves and levels, etc.).​

Enjoy,
Rich P


Hi Rich, thanks so much for the detailed step by step. My deck is now mechanically sound, but need to do full electronic calibration. My CT-F900 SM has no calibration instructions. (Where as the similar 950 SM does have, but unit not quite the same). Do you know a source for the calibration manual ? Thanks again.
 
The Pioneer CT-F900 Service Manual (Pioneer ART-320-0) has calibration instructions starting on page 29 (Electrical Adjustments). An excellent quality reproduction can be found here: http://www.stereomanuals.com/man/rep/pioneer/pioneer_manuals_ct-f_xx.htm

Rick's reproduction manuals are truly excellent. He may have an original manual also. You can contact him via links on the site I linked.

Enjoy,
Rich P


Cheers Rich. Manual ordered.

all the best. Luis
http://naks.es
 
A big Thank You. Belts and tire replacement. And a ground wire reattached ( eliminated static sound)on 950. Easy instructions to follow. Works like new.
 
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