Fostex G16S
#31
27th December 2013
Old 27th December 2013
  #31
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Richard Crowley's Avatar
 

With no reels, in Fast Forward or Rewind mode, the "receiving" spindle should have considerable torque, while the "supply" spindle should have considerably less torque. It should be easy to determine this by simply applying your fingers to the hubs to see how much friction it takes to slow them down. Many machines will run at full speed with no reels/tape, but a test with no load is not, by itself, an indication of sufficient torque for normal spooling function.

As Radardoug observes, be VERY CAREFUL about grabbing reels, espcially metal ones, when they are spinning. Even the tape itself can put nasty cuts into your fingers if you are careless. The test I suggested should be done with NO reels on either side.
Dino123
Thread Starter
#32
28th December 2013
Old 28th December 2013
  #32
Gear Head
 

Thread Starter
Hi Radardoug. Well, that is reassuring to say the least. I will attempt your approach some time later today and report back as to how much force I'm able to determine by holding the reel. Thank You Very Much for this suggestion as well
#33
29th December 2013
Old 29th December 2013
  #33
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2N1305's Avatar
 

Quote:
Originally Posted by Dino123 View Post
Hi to 2N1305 too I do appreciate you chiming in, especially since you were part of the "original" cast. My only real conundrum here is, based on the experiment which I just conducted (which is briefly outlined in a previous post), how do I know how far I need to distance the wheel spacers in order to effectively determine where the problem lies? Those rollers appear to be very sensitive to how far up or down they are relatively spaced; Does this have something to do with how much power is actually driven into each motor by the servos? I have no clue.......
Hi Dino,

first of all, excuse my delay, with Christmas gatherings and all, I completely forgot to check Gearslutz. That being said, I am quite happy to be of any service (and that won't be as much as anyone else on this thread) I can. My knowledge of this machine I hate to admit is zero, save for what it looks like and the general knowledge I have of reel to reel decks.

Anyway, without even reading any further comments which have doubt addressed your query, those wheel spacers are tension sensors, and yes they are very sensitive to tape pressure as anyone here will tell you, and yes they are mostly, as far as I understand, what regulates the motor torque. Most probably some form of PWM (pulse-width modulation) function implemented in the main IC, and while I'm thinking about it, those roller could very well be the cause of your problem. Do they move freely? Meaning, can you move them up with the slightest push of a finger? They should not need any more force than that to move...

OK, I'm going to go read the other posts...
Dino123
Thread Starter
#34
30th December 2013
Old 30th December 2013
  #34
Gear Head
 

Thread Starter
Latest Test

Hello again Folks. Radardoug and Richard - Okay, so I tried the approach of holding the receiving reel in both Rewind and FF and each respective spindle appeared to have adequate torque while the opposing spindle essentially had barely any torque at all but did nonetheless rotate. For the sake of safety, I performed the aforementioned with no reels on the hubs. Based on my previous test of this nature, I used the 1/8th inch plastic spacers to keep the rollers elevated so that I could activate the recorder without a tape loaded; Yet, how do I know whether an 1/8th of an inch is indeed the proper height? When I tried the 1/4 inch plastic spacer, it provided very different results which seemed to cause the servos to behave improperly ? And, no worries here 2N1305 for your delay in replying; In response to your post - the tension rollers do move very freely and do not require literally any force at all to push upwards. However, the higher I do push the up, the more stiff the mechanism becomes (it almost feels as though there is some spring action going on)
#35
30th December 2013
Old 30th December 2013
  #35
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Radardoug's Avatar
 

The tension rollers are spring loaded, as you push them up you will feel more force. But also as you push them up you should feel more force from the reel servos.
#36
30th December 2013
Old 30th December 2013
  #36
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brianroth's Avatar
 

As I recall, the factory service manual had a bazillion steps involving multiple trimmer pots for the reel servos.

Bri
Dino123
Thread Starter
#37
30th December 2013
Old 30th December 2013
  #37
Gear Head
 

Thread Starter
Hi Radardoug. In lieu of your last answer, I am to assume that their may indeed be something wrong here with the servos then because when I performed the initial test and used the 1/2 inch rubber spacer in order to keep the tension rollers up, the spindles acted by what I perceived to be erratic (they would respectively start and stop repeatedly). Based on the details which you provided, this is not what occurred; Thus my latest post inquired as to how do I determine exactly what thickness of spacer is in effect appropriate that would most closely emulate when a tape is actually loaded? The last test I performed I used an 1/8th of an inch plastic spacer and it appeared to be fine with a good amount of torque.
Dino123
Thread Starter
#38
2nd January 2014
Old 2nd January 2014
  #38
Gear Head
 

Thread Starter
HAPPY NEW YEAR to Everyone May all of your treats for 2014 be analog.......
#39
2nd January 2014
Old 2nd January 2014
  #39
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djmukilteo's Avatar
Quote:
Originally Posted by Dino123 View Post
HAPPY NEW YEAR to Everyone May all of your treats for 2014 be analog.......

Happy New Year back at ya Dino!
Did you make any progress with your tape transport issues?
Dino123
Thread Starter
#40
2nd January 2014
Old 2nd January 2014
  #40
Gear Head
 

Thread Starter
Hi. Still looking searching to procure some good, clean tape to test with........
#41
3rd January 2014
Old 3rd January 2014
  #41
Gear maniac
 

Try the reset function. Just turn the machine on with the stop and play button depressed.
Or you may have second function tape speed issues. But try the reset first.
Dino123
Thread Starter
#42
3rd January 2014
Old 3rd January 2014
  #42
Gear Head
 

Thread Starter
Hello thrustman. Did perform the reset procedure; Unfortunately, no cigar.......
Dino123
Thread Starter
#43
4th January 2014
Old 4th January 2014
  #43
Gear Head
 

Thread Starter
Latest update - I did what I did not really want to but...... I bit the bullet and bought a half inch tape off of eBay; Hopefully this will allow me to continue my testing......
#44
4th January 2014
Old 4th January 2014
  #44
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djmukilteo's Avatar
Quote:
Originally Posted by Dino123 View Post
Latest update - I did what I did not really want to but...... I bit the bullet and bought a half inch tape off of eBay; Hopefully this will allow me to continue my testing......
What brand/type? New or used? How much did you pay?
Dino123
Thread Starter
#45
4th January 2014
Old 4th January 2014
  #45
Gear Head
 

Thread Starter
It was a one pass Maxell for $40.00
#46
4th January 2014
Old 4th January 2014
  #46
Gear maniac
 

Never seen half inch Maxell here in Cleveland. You should try new tape after a thorough cleaning.
#47
4th January 2014
Old 4th January 2014
  #47
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djmukilteo's Avatar
Quote:
Originally Posted by thrustman View Post
Never seen half inch Maxell here in Cleveland. You should try new tape after a thorough cleaning.
Yeah, I don't think Maxell made 1/2" or wider tape....are you sure your tape Dino is 1/2" width?
#48
4th January 2014
Old 4th January 2014
  #48
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djmukilteo's Avatar
Quote:
Originally Posted by Dino123 View Post
It was a one pass Maxell for $40.00
can you provide a link to the Ebay listing?
#49
4th January 2014
Old 4th January 2014
  #49
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djmukilteo's Avatar
Not sure where you are located Dino but here is the correct spec tape for your deck (new).
If you have an empty 10.5" reel you could save some money and buy the "pancake" carton version which is just the tape which you can then load onto the empty metal reel.

This is RGMI brand SM900
RMGI-North America SM900 34720 1/2" x 2500 ft Recording Tape on 10.5" Metal Reel | Full Compass
SM911
RMGI-North America SM911 34220 1/2" x 2500 ft Recording Tape on 10.5" Metal Reel | Full Compass

This is ATR brand
ATR Magnetics ATR30907 1/2" x 2500 ft. Master Tape on 10.5" NAB Reel with Tape Care Box | Full Compass
#50
5th January 2014
Old 5th January 2014
  #50
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brianroth's Avatar
 

I've been in the pro recording biz for 40+ years, and never saw any Maxell reel-reel tape sold in widths wider than 1/4". Lord knows how many times I fought "bad batches" of one brand or another, but I THINK I would have become aware of Maxell as an alternative as I was battling with Ampex (Quantegy), 3M (Scotch), BASF, AGFA, etc. Maxell did make some decent cassette tapes....but I admit to never trying their 1/4" tape.

"This Week" I don't know which current brands of NEW tape to suggest, since they have all been having problems recently. In general, RMGI has been the best. That has been the stock which MRL has also been using for their test tapes.

Bri
Dino123
Thread Starter
#51
5th January 2014
Old 5th January 2014
  #51
Gear Head
 

Thread Starter
Hello again Folks I am very sorry for any misunderstanding on my behalf. I contacted the seller whom said that the tape is by 3M; Am I getting scammed (yet again......)
#52
5th January 2014
Old 5th January 2014
  #52
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djmukilteo's Avatar
Quote:
Originally Posted by Dino123 View Post
Hello again Folks I am very sorry for any misunderstanding on my behalf. I contacted the seller whom said that the tape is by 3M; Am I getting scammed (yet again......)
as long as your sure it's 1/2" wide tape and not 1/4".....you threw us off with the Maxell brand.
Again if you posted the link to the Ebay description so we could look at what it actually is we could be more sure...
Dino123
Thread Starter
#53
6th January 2014
Old 6th January 2014
  #53
Gear Head
 

Thread Starter
Yes, I am absolutely certain that it is 1/2 wide; Once again, I do apologize for the confusion, my bad
#54
7th January 2014
Old 7th January 2014
  #54
Lives for gear
 

From memory there is an optical tape sensor in the tape path, if you are trying to run the unit with no tape I vaguely remember from servicing them in the old days having to slip a small piece of paper in there to fox this sensor in order to get it to run the motors without tape.
Dino123
Thread Starter
#55
7th January 2014
Old 7th January 2014
  #55
Gear Head
 

Thread Starter
Hello triez. This is an interesting development; I was unaware of this consideration. Do you recall exactly where it would be situated (I only ask because I am truly not an expert here and want to make sure that I am covering the proper component). Thanx!
#56
7th January 2014
Old 7th January 2014
  #56
Lives for gear
 

Quote:
Originally Posted by Dino123 View Post
Hello triez. This is an interesting development; I was unaware of this consideration. Do you recall exactly where it would be situated (I only ask because I am truly not an expert here and want to make sure that I am covering the proper component). Thanx!
It was such a long time ago I barely remember, I worked on them when they were new in the '80's. I don't have the service manual any more, It was the B-16 and E-16 from memory.
Dino123
Thread Starter
#57
8th January 2014
Old 8th January 2014
  #57
Gear Head
 

Thread Starter
Okay, Thanx. This is a G16S, and, I cannot locate a sensor like that anywhere in the path (but, I may indeed be wrong.......)
Dino123
Thread Starter
#58
14th January 2014
Old 14th January 2014
  #58
Gear Head
 

Thread Starter
Tape has arrived!

Okay Folks, here's the latest update. I don't think that I've actually made any progress though. I received the 3M tape which I purchased on eBay and anxiously ran it through the G16S; Well, here appended is a pic of the result. I take it that this is representative of "sticky shed" syndrome. I unfortunately incurred the same symptoms of slow rewind and fast forward - If I manually raised/lower the small rollers on either side it would significantly impact the rate of take up speed. I took a chance and it appears as though I was not fortunate...... :(
Attached Thumbnails
Fostex G16S-p1140966.jpg  
#59
14th January 2014
Old 14th January 2014
  #59
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djmukilteo's Avatar
Quote:
Originally Posted by Dino123 View Post
Okay Folks, here's the latest update. I don't think that I've actually made any progress though. I received the 3M tape which I purchased on eBay and anxiously ran it through the G16S; Well, here appended is a pic of the result. I take it that this is representative of "sticky shed" syndrome. I unfortunately incurred the same symptoms of slow rewind and fast forward - If I manually raised/lower the small rollers on either side it would significantly impact the rate of take up speed. I took a chance and it appears as though I was not fortunate...... :(
Yeah not much luck with that....maybe you can get your $$$ back from the Ebait seller.
Really need to buy new tape.
Quote
1
Dino123
Thread Starter
#60
18th January 2014
Old 18th January 2014
  #60
Gear Head
 

Thread Starter
Does anyone here on the forum know of a good source for tape in Canada?
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