Ampex F4460 reel to reel.

Good morning,

While I realized that the model is a F4460, is the machine what they also call an F-44? The last 2 digits might just tell you what speeds or cabinet the machine came in, or if it was 1/4 or 1/2 track.

Anyway, if it is an F44 (Fineline 44?) I have a recollection of what Ampex techs call a "Dropped capstan flywheel" This is where the large cast flywheel dropped down on the capstan shaft be cause the press fit wasn't tight enough. I think you can check this by taking the top panel off the unit so you can really see the flywheel, and just try pulling up on it. If that's the case then you can take the whole thing out of the machine, clean the capstan shaft and flywheel from grease, and refit the flywheel with some epoxy so it stays where it it supposed to.

If this is an F44, contact me off-group. I might have a manual for the thing somewhere in the archives.

Regards, Tim Schwartz Bristol Electronics

But why does it matter? The pinch roller does not need friction to the tape. It is the capstan that needs that. I can see you might need some resilience so that the tape is not nipped too tightly and thus reduce the contact pressure, but that's not really a surface attribute.

Mike.

1850?? How can the motor do 1850 on 60 Hz power? Many tape decks used hysteresis-synchronous motors, so they were designed to spin up as induction motors and then lock to the mains as synchronous. A 4-pole motor would run at exactly 1800.0 RPM. 1795 with a strobotac is probably 1800, and your strobotac is just a hair off calibration. You might just use a nean lamp in series with a resistor and diode to make an exact 60 Hz strobe, and see if a mark on the motor shaft stands still.

Jon

** It absolutely does.

The simple explanation is in the words you snipped.

** The capstan has no grip to the tape - since polished steel and smooth tape have no mutual friction. ** A shiny surfaced roller has no grip to the capstan. Why the heck do you think pinch rollers ( along with idler tyres and drive belts) are made from soft rubber in the first place ?

You ever serviced a tape recorder in your life ?

.... Phil

No need to be rude! Actually I have only serviced special purpose players, for a decade or three until they were discarded in favour of CD drives. The media are all pre-recorded.

I said why I thought the pinch roller needed to be resilient; just a matter of physics and pinch pressure. But now I see that you are relying on an unstated but reasonable assumption: that the pinch roller is wider than the tape so gets driven by the capstan on its margins and drives the tape between those margins. You could, of course, have explained that instead of ranting...

Mike.

I have to admit that your explanations for pinch rollers is dead on. A worn or dry roller would cause slippage though, so rough it up and try again.

As for the OP, Not sure how much I'd trust a 400 year old tach. It may be time for a cardboard disc and a neon light to check for speed problems with the motor. You don't need as many lines as on a turntable either.

Hello everybody,

I doubt that his issue is a pinch roller no matter how badly glazed it is as his machine is running SLOW, and it the tape is being pulled ahead by the take-up torque overpowering the capstan/pinch roller, it would be running fast.

Regards, Tim Schwartz Bristol Electronics

** But a capstan spinning against a glazed roller will slip and hence not d rive it round at full speed.

Most of my recent experience is with Roland tape echoes which use a 5 metre long loop squirming around in a box. Back tension come from pairs of felt pads the tape passes between as it leaves and enters the box.

When the roller is glazed, tape speed is slow and unsteady.

Also, tape becomes slightly sticky with age and grips to the heads as it pa sses over them - so much so that in some cases the loop will stop moving co mpletely until you lift the tape off the heads and start again. This is the case even when the pinch roller in perfect condition.

The fix here is to clean all the heads and guides and replace the loop.

.... Phil

I took a quart glass bottle to a local print shop and they filled it with platen cleaner for $10. They buy it in 55 gallon drums. Smaller shops buy it in five gallon cans.

--
Anyone wanting to run for any political office in the US should have to 
have a DD214, and a honorable discharge.

I saw a lot of loose flywheels on cheap 8-track tape decks around

1970. We would pull the capstan and flywheel, then use a small center punch and hammer to put four equally spaced dents near the capstan, on the bottom side of the flywheel.

--
Anyone wanting to run for any political office in the US should have to 
have a DD214, and a honorable discharge.

It's the lack of pliabililty. They call it a pinch roller because it pinches the tape. A hard rubber puck is useless. The exact dimension isn't critical as long as the bearings fit and the plunger goes far enough.

** You must be thinking of pinch rollers used in VCRs which often have an internal ball race.

The vast majority RR and echo machine rollers simply have a plain bearing running on a shaft of about 4 or 5mm dia.

All the Roland 1/4 inch tape echos have a roller that is 12mm x 28mm running on a 6mm shaft.

.... Phil

The rotating capstan controls the speed, the roller makes sure the tape doesn't slip. There used to be a couple high end machines without pinch rollers from Japan.

I spent many years fixing Ampex 600, 300, 351, 440, PR10; Otari MX5050; ATC, Spartamatic, ITC cart machines. If the reel tension is right the roller barely does anything.

I love when you turn the Space Echoes up too high and they make their own music.

Got this tape echo machine at work. Got tubes. Old. Tape runs and it was a fresh job for me. I see it has bias and audio mixing with it. It passes sig nal but does not echo. I think the tape is simply bad.

Anyway, it has no pinch roller. The tap goes about 1430 degrees around it t hough. That is apparently enough.

However O think this arraingement would cause faster tape deterioration due to more bending. Isn't the straightest path the best ? (for the tape itsel f of course)

It is kept under tension by a springed idler. There are no tape pads. It ha s a magnetic erase head between a fixed and spring loaded idler or tensione r. Lke a turing tape guide. The capstan is way over on the right side. Ther e are like five heads, electronic heads not the PM erase head. I am probabl

hat is not in great shape. It will deteriorate quickly but I do know that i t actually records. The stuff on there really looks funny. Red not brown. O f course that doesn't rally mean anything but that it is unusual a little. Thing is that it is not really opaque.

I am actually disappointed by the thing not hav ing a speed control. What, they didn't have eddy current motors in the 1940s ?

Cheapskates.

a fresh job for me. I see it has bias and audio mixing with it. It passes s ignal but does not echo. I think the tape is simply bad.

though. That is apparently enough.

ue to more bending. Isn't the straightest path the best ? (for the tape its elf of course)

has a magnetic erase head between a fixed and spring loaded idler or tensio ner. Lke a turing tape guide. The capstan is way over on the right side. Th ere are like five heads, electronic heads not the PM erase head.

** You just MIGHT be describing Charlie Watkins' famous little horror - the "WEM Copycat" first released in 1958.

A truly horrible machine that just barely worked, it's output was riddled w ith AC hum, tape noise (from the permanent magnet erase) and serious wow & flutter plus amplitude modualtions.

Charlie was too cheap to admit it needed a pinch roller.

Modern 1/4 inch tape normally refuses to run on a WEM Copycat as the surfac e friction is just too low. You could try fitting a shrink plastic sleeve o ver the capstan if you like.

, they didn't have eddy current motors in the 1940s ?

** Some very cheap echos used simple, DC brush motors and others had two sp eeds - but the first machines to feature decent, BLDC variable speed motors were made by Roland of Japan. Models include the RE101, RE201, RE301 and d eluxe versions were the RE501 & SRE555.

A fairly large BLDC motor branded "Pioneer" provided direct capstan drive a nd continuously variable speed range of about 5:1 with varying compensation applied to EQ circuits as tape speed changed to keep the response flat. Th ere was also an NE570N compander IC to reduce tape noise to quite low level s.

The erase head was ferrite cored and the record and play heads had stainles s steel face plates that simply never wore out.

Nice machines, fixable and well worth fixing even today.

.... Phil

On Wednesday, December 17, 2014 12:53:27 AM UTC-5, snipped-for-privacy@gmail.com w rote:

d I'd like to listen to some of my old tapes. I cleaned and lubricated it, demagnetized the heads and put a tape of some familiar music on, and I thou ght it seemed a bit slow. So I repeated it with other tapes and then follow ed with an Ampex frequency response alignment tape. The scope was calibrate d to 1.0ms off the 1KHZ square wave output and then I looked at the the 1KH Z sine wave off the tape. The period was approximately 1.40ms which appears to translate to 714HZ. Truly hard to believe that it's running that slow, but I don't think that the equipment is lying.

tor is rated for 1850 RPM at 115V, and it's running rock solid at 1795. I tried loading it while watching the speed and it remains steady, so it does n't appear to be a load problem. Could such a slight motor speed reduction cause a 25 percent reduction in the frequency of my 1KHZ test tone off the tape? It doesn't seem possible, but I don't know.

aven't investigated this yet, but with four wires going into it I figure th at the cap must be on the chassis somewhere. I wouldn't think that a cap pr oblem though would cause my RPM's to drop 55RPM would it? Oh and I have no service manual, however I don't think that service manual would do me much good with this problem anyway.

ks, Lenny

Well I thought I'd jump back in here with an update on my progress. I order ed and installed a replacement capstan flat belt from Adams Manufacturing. After installing this belt there was no more bumping from the old misshapen belt. then, I had three pinch rollers. One is from this machine and the ot her two were from junkers I had in the shop. The rubber on all of them was slick but seemed pliable and I worked on two of them with sandpaper and the n lacquer thinner. I finished off with rubber restorer and then cleaned the m off with 99% anhydrous isopropyl. After this treatment The rollers felt a bit more "grippier" if that's the correct description but still were not w hat I would have liked to see. However taking a fresh look at the 1KHZ tone on the test tape with the scope immediately after installing one of the "r estored" rollers showed that the machine was now running on speed. So I fee l foolish to admit that it seems that I had overlooked the most basic thing , the capstan roller, as being the primary governor of speed.

So I tried a few of my old tapes to see how they sounded. Some of these tap es were 1800 ft and I noticed that they would play for a coupe of songs and then start slowing down. I had a sealed brand new roll of Scotch 206, whic h is a 1200 ft low noise mastering tape as it's so called. I made a fine so unding recording on this tape. Then I tried playing the 3 3/4 pre recorded Bob Dylan tape. Let me tell you when Bob Dylan is off speed there is no mis taking it. So while this was running I gently increased the take up torque with my finger and the tape seemed to sound fine as long as I kept the tens ion up. As soon as I relaxed it a bit the speed would waver.

So now I know that for certain I need to resolve the pinch roller issue and also I need to check the take up torque for which there is a specificatio n in the manual. Problem is I don't have a scale for that. So I as wonderin g if anyone knows of a source for these type of scales, and also as I found for the capstan belt is there a generic source for replacement pinch rolle rs? Or as a substitute can a pinch roller be "rebuilt"?

My wife just can't understand why I've been screwing around with a 50 year old machine when she has so much other shit for me to do. But I know that y ou guys know and can appreciate the sense of satisfaction associated with b ringing a dead body back to life. And I feel like now I'm so close. Thanks for any further advice. Lenny

the "WEM Copycat" first released in 1958.

"

That is it but I think it has a differnt name on it. It IS Watkins but I th ink a different word than "copicat". I'll look. they don't care they just w ant it to work if possible. that's why I went to hourly pay a long time ago , if it ain't worth it I still get money.

Well the motor is directly under the capstan. I would've take a bit differe nt approach to say the least. Looks like a four pole or better though at le ast which has less flux leakage. Sometimes I wonder how these reel to reel manufacturers dealt with it. And then some with relay control of AC solenoi ds ! They must've been crazy back then - but then again we know they were.

It seems to have some type of special tape. It looks different, it is RED.

mera just took a shit otherwise I would put up a picture in the next few da ys. Hah, and guess what is in the compartment on the left. A roll of splic ing tape. I do not have a splicing block but I am sure I can manage just to get it working. the tape I got laying around is too old anyway. I got even older tape with oxide falling off, htis stuff seems to wear down quickly t o where it has alot of drag. Record and play, and I mean on a good deck lik e two Teac A-3340 and a Tandberg 9400 and shit, after a few passes it got s o sticky it didn't even want to rewind. these are all three motor decks wit hout tape pads so it is not the deck. In fact the tape with the oxide falli ng off rewound just fine but spewed the oxide all over the place.

ace >friction is just too low. You could try fitting a shrink plastic sleev e over >the capstan if you like. "

Well, even though it really doesn't go 1430 or whatever degrees around the capstan it might concievably work if the drag is very low. It will surely s till f*ck up but at least I will have a chance to test it. Getting absolute ly nothing, well first of all there are more than one playbeck and NONE of them work. Logically that indicates the tape is probably FUBAR oxide wise.

You know the tape might have been coated with something. I would not approa ch it like that but maybe they did. Which means can't get the tape of cours e and nice modern tape is not likely to work well. but I can't even justify that cost. Friggin I saw sometning like $240 for a 1200' roll ? that is a bit steep but really is in line with the economy. I onder if they want to s ell it by the foot. That's like buying individual cigarettes instead of a p ack I guess. But still, with no pinch roller it might not have the tracktio n.

Being a vintage unit I doubt I want to modify it with a pinch roller. For o ne I would have to establish a machine surfacr to get it straight, on a uni t that is alread buiolt. Fuck all that.

Other thing, the idea about the sleeve on the capstan might not be a piece of cake unless I can find it precision, no taper etc. I do have some plasti c tips for the hold down on Premier cigarette machines that really would wo rk IF they were straight. Perpendicular and allt that, constant thickness. But they aren't. And they are not machinable.

So this thing might sit for a while. It is not a rush job to say the least.

and >continuously variable speed range of about 5:1 with varying compensat ion >applied to EQ circuits as tape speed changed to keep the response flat . There >was also an NE570N compander IC to reduce tape noise to quite low levels. "

Yeah, try doing that with tubes. Really, I could see it happening but nowhe re near the performance. Variable gain tubes, modulate the G2 voltae of pen todes and all that, it can be done.

This compander, like DBX eh ? That brings up a question.

Was there ever a tube Dolby unit ? Now that would be some engineering I thi nk.

Enough, time to eat. I will be back at the antagonization station later.

apes >were 1800 ft and I noticed that they would play for a coupe of songs and then >start slowing down."

That is not a symptom of a bad pinch roller. I believe you might find heati ng up motor bearings, or capstan bearings, or maybe even a leaky motor cap. When pinch rollers go bad they usually do not wear or harden exactly unifo rmly and they screw up the tape path. It will hit the guides and actually e ven get damaged. This was VCRs, and the tape path in those is every bit as critical as audiophile or pro R2Rs if not moreso.

I would run it as far apart as possible and see if the RPMs go down playing , then see if they jump back up not. And then if they do, try to slow it do wn with your hand, maybe with a rag. I would do the same to the capstan.

I doubt you are mistaking muffled sound for slowing down. A pinch roller CA N cause that by affecting the tape path.

Ho about recording a test tape with like a 1 kHz signal on it. In fact make it a square wave. You can read the timing of it, and it will reveal the re sponse curve. I say that because this whole thing doesn't sound right. Ther e is an argument about pinch rollers now but that matters not. The load on the motor from ANY pinch roller (you kno you CAN use metal if you cna machi ne it well enough) should never pul down the motor RPMs. In fact even runni ng Scotchtape (I mean the kind you stick to things) in it, it should break the tape, not stall or slow down. It should not happen. It should take a pa ir of Visegrips (tm) to stop that thing.

captainvi

ered and installed a replacement capstan flat belt from Adams Manufacturing . After installing this belt there was no more bumping from the old misshap en belt. then, I had three pinch rollers. One is from this machine and the other two were from junkers I had in the shop. The rubber on all of them wa s slick but seemed pliable and I worked on two of them with sandpaper and t hen lacquer thinner. I finished off with rubber restorer and then cleaned t hem off with 99% anhydrous isopropyl. After this treatment The rollers felt a bit more "grippier" if that's the correct description but still were not what I would have liked to see. However taking a fresh look at the 1KHZ to ne on the test tape with the scope immediately after installing one of the "restored" rollers showed that the machine was now running on speed. So I f eel foolish to admit that it seems that I had overlooked the most basic thi ng, the capstan roller, as being the primary governor of speed.

** Hallelujah !!

apes were 1800 ft and I noticed that they would play for a coupe of songs a nd then start slowing down.

** Old tape get sticky and requires many passes through a machine to clean up, you may need to clean the heads with ISO over and over too.

I had a sealed brand new roll of Scotch 206, which is a 1200 ft low noise m astering tape as it's so called. I made a fine sounding recording on this t ape. Then I tried playing the 3 3/4 pre recorded Bob Dylan tape. Let me tel l you when Bob Dylan is off speed there is no mistaking it. So while this w as running I gently increased the take up torque with my finger and the tap e seemed to sound fine as long as I kept the tension up. As soon as I relax ed it a bit the speed would waver.

** The reel of 206 is probably sticky too - creating extra back tension tha t the capstan has trouble pulling through. ** Sanding the surface smooth while spinning the roller in a bench drill ha s always worked for me.

For a R-R machine to work properly, so many things have to be just right.

Not the least of which is the tape itself.

... Phil