Ampex 2163 Reel to Reel Belt Replacement

[DMcMahon]

As referenced in Post #1 of my Ampex 1100 Series Thread, a friend of mine asked me to check out his 2163 where all 3 rubber drive belts had turned to a gooey mess.

https://www.vintage-radio.net/forum/...d.php?t=186129

He had spent quite some time cleaning up the worst of the mess without dis-assembling the unit and a couple of days back delivered it to me.

I have cleaned up the worst of the remaining mess, it was extra stubborn despite trying all the usual cleaners/cleaning methods, leaving some black marks on metalwork where the runner has stained/become engrained.

There was quite a bit of rubber around the top rewind idler pulley, while cleaning this found that pulley will not rotate. There is some sort of electrical coil that sits above the pulley and there are 2 metal legs from the coil that sit either side of the pulley.

Initially thought it maybe is some sort of electro magnetic brake but see on my 1163 (which has the same hardware) that the pulley does rotate and there is no electrical supply to energise the coil, so assume it must be some sort of sensor.

On the mechanical layout drawing the coil is shown but with no item number so cannot easily identify it from service manual parts list. Not yet seen it on the schematic.

So now thinking that the pulley is just gummed up internally with belt goo. Not sure how to remove it, the drawing seems to show it is retained by a vinyl O ring (item 230), there is a small white item there but it is not keen to come out.

Struggling at the moment to fit the new largest drive belt that goes around the 2 flywheels. To fit the belt have to lift up assembly that sits above the flywheels but one of the three securing screws holes is partly blocked by the Play solenoid so cannot access that screw, not yet worked out how to remove the solenoid.

David

[DMcMahon]

Originally Posted by DMcMahon

I have cleaned up the worst of the remaining mess, it was extra stubborn despite trying all the usual cleaners/cleaning methods, leaving some black marks on metalwork where the rubber has stained/become engrained.

Typo edit in bold above.

David

[DMcMahon]

Originally Posted by DMcMahon

On the mechanical layout drawing the coil is shown but with no item number so cannot easily identify it from service manual parts list. Not yet seen it on the schematic.
David

Have now found the rewind pulley coil on the schematic, it is L101, used with the 20Hz generator during recording for auto reverse at end of tape (or at any other chosen place on the tape). It is item 237 on the 2163 parts list, previously was looking at 1163 manual where it has no item number on the drawing.

With a lot of persuasion managed to remove the rewind pulley and after cleaning and lubrication it now rotates fine. Think it was thick dried up oil rather then belt goo that was stopping the pulley from rotating. The end section of the pulley is magnetic. The retaining O-ring is white and appears to be rubber like, it is called "Vinyl", I have never heard of a Vinyl O ring before.

By unscrewing the retaining nut for the Play solenoid and moving the solenoid to the side, then was able to get screwdriver into the third securing screw for the assembly that sits above the flywheels. During this dropped the nut and quite large thick spring washer down at the bottom of one of the flywheels. Retrieved the nut but could not reach the washer and it subsequently disappeared somewhere, I have a horrible feeling that it could have rolled underneath the flywheel and is in the void space underneath.

I gave the recorder a good shake but no sign of the washer but a long brass coloured metal rod fell out from somewhere, it looks familiar so need to find where it belongs. May have to unsolder quite a few wires to be able to lift away the assembly above the flywheels to remove the flywheel to try and locate the washer.

David

[DMcMahon]

After another good shake the Play solenoid spring washer fell out from somewhere.

Found where the brass coloured rod/pin resides, its fits in a hole in the rear of the front casting and when the Play button is lifted up the pin is pushed out and pushes against the large brass coloured Play actuator lever plate. The plate pushes the rear of the sprung loaded reel tables down, unsure what the function of this is.

Forgot to mention that when the Rewind pulley was removed found that there was some rock hard blue belt debris present, similar for the tape counter pulley, so that was removed/cleaned.

Have fitted the new drive belts and almost re-assembled everything so soon to power up and test. As imagined getting the belts correctly fitted around the motor pulleys was very awkward, will be somewhat easier when I come to replace the belts on my 1163 now that I know what I am doing and the order parts have to be refitted.

I am not 100% sure if I have refitted the Play actuator lever plate correctly. On its left side it has an extension piece that has an hooked end, it looks like the hook should connect onto something. There is another lever that comes out of the amplifier unit nearby and it looks like the plate extension piece should hook onto the lever but the lever is not close enough.

When I stripped it down I did not notice if the extension piece was hooked onto the lever.

Presumably one of the amplifier front panel controls must move the lever but have not found yet which one, hopefully when powered up and working will find out and then see if the lever should be connected at some point to the hook.

The amplifier lever also will actuate a sprung loaded shaped rod that looks like it will lock the Reverse lever in both of its positions but because currently cannot see which control moves the lever cannot see when the reverse lever will be locked.

Looking at my 1163 for comparison it is completely different, the Play actuator lever plate extension piece does not have a hooked end, it is a shaped piece that pivots on the amplifier chassis and the end of the piece just looks like it is a mechanical stop to limit how far/hard the rear of the reel tables are compressed down. There is no lever coming out of the amplifier chassis and there is no mechanism to lock the Reverse lever.

David

[DMcMahon]

Did quite a bit of internal cleaning particularly removing a lot of "white rust" corrosion on various metalwork, presume it must have been in a damp atmosphere for quite some time.

My 1163 (also dated 1966) by comparison has little if any white rust present.

David

[DMcMahon]

Tonight powered it up, it partially works but with problems which is very disappointing.

All 3 speeds work but intermittently Play mechanically is noisy (knocking sound), fast forward wind works well. Rewind does not work at all, it does work with just a spool or spool + tape only on the Supply table.

With headphones connected only get playback on the left channel, not yet tried with speakers or line outputs. So plenty to sort out.

David

[DMcMahon]

Forgot to mention that before powering up, stood the unit vertically to fit the spools and a tiny rubber covered spacer (like a miniature pinch wheel) fell out from somewhere.

Have never seen this part before, so do not think it was deliberately disturbed during the strip down for belt replacement. Have been scouring the drawing and parts list but so far can see nothing that it might be.

David

[Kentode]

David, re: the knocking sound, a good tip l was taught (on adjustable gears) is to put a pencil/chalk/tippex mark on the outer edge of every part that rotates. When you hear the knocking, look for a mark which is always at the same position i.e. seven o'clock. Then look at the mating surfaces of the part knocking.

Hope this helps.

[DMcMahon]

Thank you Ken, good input, I will check that out later, have not had a chance to get back to it yet.

The knocking is fairly intermittent and sometimes is more on the Supply spool side and at other times more on the Take Up spool side, it can be quite severe.

Would like to think that it should not be too difficult to pinpoint the source but at the same time can hear the phrase "famous last words" ringing in my ears

David

Edit update in bold above.

[DMcMahon]

Originally Posted by DMcMahon

I am not 100% sure if I have refitted the Play actuator lever plate correctly. On its left side it has an extension piece that has an hooked end, it looks like the hook should connect onto something. There is another lever that comes out of the amplifier unit nearby and it looks like the plate extension piece should hook onto the lever but the lever is not close enough.

When I stripped it down I did not notice if the extension piece was hooked onto the lever.

Presumably one of the amplifier front panel controls must move the lever but have not found yet which one, hopefully when powered up and working will find out and then see if the lever should be connected at some point to the hook.

The amplifier lever also will actuate a sprung loaded shaped rod that looks like it will lock the Reverse lever in both of its positions but because currently cannot see which control moves the lever cannot see when the reverse lever will be locked.


David

Now happy that the Play actuator lever plate is correctly installed.

The lever that comes out of the amplifier module is the Record Slider, this pushes out when the Record safety button is pressed in (button does not stay in at this stage).

When the Play/Record lever is lifted up the extension piece on the Play actuator lever plate sits inside the Record slider to stop the record button from being pressed (i.e. During play record is interlocked).

With the Play/Record switch set to record AND the Record button pushed in AND then the Play/Record lever lifted, this moves the extension piece to the outside of the Record Slider (presses into it rather than hooking around it), this locks the Record safety button in for Recording.

Pushing in the Record safety button which moves the Record slider out results in the slider pushing against the sprung loaded shaped rod that results in the Reverse lever being locked to stop a change of direction being selected during Recording.

David

[DMcMahon]

Originally Posted by DMcMahon

Forgot to mention that before powering up, stood the unit vertically to fit the spools and a tiny rubber covered spacer (like a miniature pinch wheel) fell out from somewhere.

Have never seen this part before, so do not think it was deliberately disturbed during the strip down for belt replacement. Have been scouring the drawing and parts list but so far can see nothing that it might be.

David

Found the part belonged on the L.H. Capstan Idler assembly, had previously noticed that the idler was slack in its movement slot (due to the missing part) but had not associated it with the found part. Still cannot see the part on the drawing so must come as part of the Idler assembly. Refitted OK, difficult to see how the part could have come out in normal operation as does not seem to be enough depth underneath to allow the part to come off the idler shaft/pin with idler fitted.

David

[DMcMahon]

Re no right channel playback.

Found that both left and right channels work well in reverse playback, which is good as that proves that the amplifier electronics are good. Still no playback on the right channel in Forward playback but somewhat different than originally as now get quite loud hum on the right channel plus a tiny hint of a different track.

Will checkout the track switching which is actuated by the Reverse lever mechanism.

Visually checked out the head wiring and all looks OK, cleaned heads at the same time.

David

[DMcMahon]

Found the ends of a 2 legged spring were floating/not fitted to anything so the 2 associated lever assemblies were just floppy not sprung loaded.

Only 2 obvious places the end of the spring arms could fit so fitted them there and now the lever assemblies are sprung loaded.

My 1163 has the same spring but with only 1 lever assembly and unlike the 2163 I can see no obvious place to fit the end of the spring legs, have tried fitting them in a couple of locations but as soon as the Fast Wind lever is lifted up the ends of the springs lift away and the lever then becomes all floppy.

David

[DMcMahon]

Found a moveable tape post was very stiff, this is for End of Tape (EOT) operation. Tried to free it in-situ but could not. By removing the top dampner arm section was able to get it free and rotating correctly to operating the EOT switch when tape loaded, the fast wind when lifted will also operate the switch when no tape is loaded. Unable to remove the tape switch arm because it sits below the flywheel and cannot be removed without removing the flywheel.

The EOT operation now works but I am baffled by the circuitry as it does not appear to be as per the schematic, more on this later.

David

[DMcMahon]

Been trying to work out why Rewind does not work when loaded with tape/spools.

Looks like the wind drive pulley rubber tyre which drives the supply reel table is not making sufficient contact, by pushing up the Arm Yoke sub assembly (which the two drive pulleys are mounted to) gets rewind working.

Cannot easily see anything actually wrong, will need to strip out the back of the recorder to see and access things better.

David

[DMcMahon]

Removed the Yoke assembly to check the black rubber fast wind tyres, both look to be the same, no obvious difference. I will swap the 2 tyres over to see if that swaps the rewind fault over the fast forward.

Note the blue tyres for forward and reverse play. On my 1163 they look like small round black O-rings, I assume they were not blue originally (remains of the gooed up tape counter belt was also blue). The blue tyres are very sticky and one of them looks like it may split apart sometime soon. Surprising they have expanded so much, they still seem to be doing their job OK though.

David

[DMcMahon]

Nothing really found wrong with the fast wind tyres but I swapped them over and now rewind works very well and fast forward is still working but not as positive as rewind, not sure if this due to having swapped over the tyres or something else.

The knocking sound has intermittently returned both on play and fast wind, seems currently coming from Take Up reel table. While it is sort of working I started to recheck the missing right channel/hum on forward play. Exactly as before on headphones but when I tried the line phono outputs into external amplifier got terrible hum on both channels, then found that my 3.5mm headphones jack adaptor to 6.35mm jack has broken and part of it is stuck inside the headphones jack socket (not sure if this is the cause of the hum on the line outputs).

Trying to get inside the amplifier to hopefully get access to the broken piece but proving really difficult.

David

[DMcMahon]

After quite some struggling found way into the headphones jack socket and removed the broken tip of the headphones adaptor.

Using another set of headphones with 6.35mm jack plug, tested the 2 switches that are opened when the jack plug is inserted.

Had a quick look inside the amplifier, really hope do not have to do any fault finding in the amplifier as it would be extremely difficult access wise to do any meaningful fault finding.

Now to re-assemble the amplifier unit which I am not looking forward to.

David

[DMcMahon]

Before re-assembling thought I would check out the earthing of the phono line output connectors, was wondering why had got such load hum when I connected them up to external amplifier.

Measuring the mains plug earth pin to the bodies of the phono line output connectors measured a very erratic 40-50 Ohms.

Opened up the power supply unit to check out the earthing connections. The green earth wire on the mains cable just connects to a metal tab/leg on the 115V/230V mains selection changeover slide switch, the tab being part of the switch body metalwork which is riveted to the power supply metal case.

Checking the rest of the power supply there is no electrical/mechanical connection from earth to the ground side of the power supply output, the ground side of the power supply does connect out via connectors to pre-amp and power amp units.

Have mainly been looking at the 1163 schematic which shows the ground side of the power supply connecting to earth (but not identified how the earth is picked up).

Checking the 2163 schematic (which is poor quality and difficult to read) it shows the power supply within a dotted outline box and does not show the mains earth connected to power supply ground but does show the ground connections of the electronics connecting to earth.

The phono line output connector bodies do measure good to the metalwork of the pre-amp unit and to the ground of the electronics in that unit, so when the power supply unit is secured to the pre-amp, unit the earth connection to the electronics ground will be provided by the metal to metal contact between the units.

When I previously measured the 40-50 Ohms, the power supply was not making good metal to metal contact with the pre-amp unit.

So a bit of a time consuming red herring but at least I now now how the earth is connected and also found the Bias Oscillator board hiding within the power supply unit

David

[DMcMahon]

After several days of kitchen DIY work and subsequent ongoing crippling back pain (caused by lifting heavy granite composite new sink in and out of unit numerous times) slowly getting back to this.

Rebuilt the unit and retested. As before on headphones listening reverse playback is good on both channels but forward playback only has good sound on the left channel with no sound on the right channel apart from hum and a slight hint of another track playing.

On line outputs get the same results as headphones.

Because both left and right channels playback is OK on reverse playback believe the pre-amp and output amp electronics must be good.

So the bad right channel on forward playback must be a bad connection most likely the track change switch, which is operated by the reverse lever. I guess it could also be the Forward PB/Record head being open circuit but hopefully unlikely.

Looking at the track change switch now, it feels very flimsy and loose switch contacts wise. Trying to figure out all the wiring connections, a little confused by the fact that some of the head wires go to 2 metal contacts (maybe test points ?).

David