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Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc. |
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2nd Sep 2021, 9:59 pm | #21 |
Dekatron
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Re: Baird TR1 Reel to Reel Coil Connections
Removed tape pressure pad arms and pressure roller to be able to more easily clean the heads and surrounding tape path. Cleaned (first pass) the top area of the tape deck, much more dirty than I thought it was and some parts really difficult to clean properly may need a second pass of cleaning later if can get the deck to run.
Tape counter drive belt is missing, when I originally cleaned out the case found a bit of old twisted dried up belt, maybe this was remnant of the counter belt. On the top of the deck found a tiny metal piece like a spacer, no idea where this might have come from. Powered up the deck for the first time (with no tape), lots not working or not working well/correctly. Forward motor works OK but reverse motor does not spin, it tries but just rotates a bit extremely slowly, manually the reverse motor feels very stiff compared to the forward motor. When Forward Play/FFD pressed the flywheel rotates but no sign of the Take Up reel table rotating, can not yet see how it would rotate drive wise. In forward Play all 3 speeds work in terms of the flywheel speed changing but somewhat erratic whether the selected changed speed will take effect. Judging by the speed of the flywheel FFD speed is no higher than 15 IPS play speed, does not seem right. Reverse Play and Rewind do not work at all due to reverse motor hardly rotating. All 7 tape transport buttons/keys are stiff to very stiff to push down So plenty to do to try and get the tape deck mechanically working properly. David Last edited by DMcMahon; 2nd Sep 2021 at 10:04 pm. |
4th Sep 2021, 8:54 am | #22 | |
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Re: Baird TR1 Reel to Reel Coil Connections
Quote:
The tape counter was introduced on the Mk. III Various changes were implemented on the Mk. IV including adding some extra switches which mine does not have. David |
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4th Sep 2021, 7:26 pm | #23 |
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Re: Baird TR1 Reel to Reel Coil Connections
Been trying to remove the reverse motor to try and fix the stiff rotation when manually rotated/not spinning when motor is powered, but really struggling to remove it. The removal instructions in the manual are not fully correct. They refer to remove a C clip then lift clear the cranked lever (speed change link arm). But the C clip does not retain the cranked lever. The lever is connected to the speed change cam assembly, so the cam assembly needs to be partially stripped down to enable the cracked arm to be removed, but there is a screw that needs to be removed which is just about inaccessible.
Because the reverse motor is next to the pre-amplifier unit which makes it more difficult to work on, I have been trying remove the forward motor first to see how it comes out. A bit of a nuisance the pre-amplifer unit being wired to the tape deck, it makes it awkward when turning the tape deck over. I think the only practical way of removing the reverse motor will be to remove both motors together connected to the speed change link then should be able to remove the reverse motor. Seems a ridiculous way of doing it but cannot see any alternative. Why doing the above noticed that the securing screw and washer for the forward idler are missing. Also comparing the reverse and forward motor assembies there appears to a spring missing from the reverse motor assembly because it has 3 springs whereas the forward motor assembly has 4 springs. David |
5th Sep 2021, 9:22 am | #24 |
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Re: Baird TR1 Reel to Reel Coil Connections
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6th Sep 2021, 11:27 pm | #25 |
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Re: Baird TR1 Reel to Reel Coil Connections
Removed both motor assemblies and stripped down very stiff reverse motor.
David |
7th Sep 2021, 9:55 pm | #26 |
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Re: Baird TR1 Reel to Reel Coil Connections
After stripping, cleaning and lubricating the Reverse motor now rotates very easily manually and runs well when 240 volts applied, actually starts rotating at around 110 volts.
Started stripping, cleaning and lubricating the various parts of the speed change cam assembly (which all are part of the motor assembly), all the parts were stiff in their different sprung loaded motions. Prior to removing the motors one of the speed change cam assembly springs got badly mangled up after getting caught in the EL 84 valve retainer spring during the various turning over the tape chassis together with the pre-amp chassis movements. Have partly un-mangled the spring as per photo, a bit more work on it is required. Also have to find a suitable spring for the missing spring on the same assembly. Been trying to work out how this speed change cam assembly actually works, not easy to visualise. Will become clearer when motors refitted etc. Also been trying to work out why previously when tested there was no drive to the Take Up reel table in Forward Play & FFD (and possibly no drive to the Take Up reel table in Reverse Play and Rewind if reverse motor had worked). Not clear yet but think it is related to the positions of the tape tension arms. Will refit motors (Forward motor assembly to be cleaned/lubricated but not stripped) after checking out the tape tension arm operation. Also need to check out the stiff tape transport control buttons. David |
9th Sep 2021, 3:57 pm | #27 |
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Re: Baird TR1 Reel to Reel Coil Connections
Both tape tension arms are very stiff to move, they should easily pivot around their mounting shafts and a spring on connected linkages should pull them back to rest position.
Pretty sure they are just gummed up on the shafts, have tried IPA and WD40 in situ but little improvement, looks like quite a bit to disconnect to get them out to clean properly. David |
9th Sep 2021, 4:26 pm | #28 |
Octode
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Re: Baird TR1 Reel to Reel Coil Connections
Sometimes tension arms are lubricated with sticky grease (kilopoise) to damp out oscillations - no idea if this is the case here.
I was thinking how characteristically Collaro the motors looked, then looked further up the thread where you say it uses the the Collaro transcrptor deck...... |
9th Sep 2021, 7:17 pm | #29 |
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Re: Baird TR1 Reel to Reel Coil Connections
Thank you Barry, I did not know that, in fact also had to Google kilopoise.
In this case they definitely are seriously gummed up. David |
9th Sep 2021, 8:08 pm | #30 |
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Re: Baird TR1 Reel to Reel Coil Connections
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9th Sep 2021, 9:38 pm | #31 |
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Re: Baird TR1 Reel to Reel Coil Connections
After a struggle removed the right hand side tape tensioner parts, doing one side at a time so that have something to compare to when refitting the parts. In the Collaro manual there is a procedure for removing the tape tension arm + spool carrier which references removing a spring from the arm that connects to a long lever that goes across the deck.
The spring was tightly double coiled around the threads plus sealed at one end with red something, found it impossible to remove the spring without wrecking it so had to remove the tension arm still connected by the spring to the lever by removing the lever as well which was not easy at all and I partially mangled the end of the spring doing it. If the spring had been removable it would have made the job a lot easier. The tension arm was well stuck to the shaft on the spool carrier plate but eventually parted the parts, there was some rock hard dried grease on the shaft, after cleaning the tension arm, it now rotates very nicely on the shaft. I have put some ordinary grease on the shaft, Superlube which is somewhat sticky so may possibly help with damping, will see if there are any oscillations later in operation, if so then may have to try Kilopoise or similar. The procedure in the manual does not reference any lubrication for this area. Because it was so difficult to remove the parts and there is the risk of the spring on the left hand side tension arm getting damaged I will have a rethink how to tackle the left hand side, will first try and ease the stiffness by exercising it in situ, the left side although very stiff is not as stiff as the right side was. David |
9th Sep 2021, 9:52 pm | #32 |
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Re: Baird TR1 Reel to Reel Coil Connections
Forgot to add that fairly sure that the very stiff tape tensioner arms are the root cause (or at least a major contributor) of why the 2 x Play and 2 x Fast tape transport buttons are so stiff tp push down because these buttons push out the respective tension arm.
David |
10th Sep 2021, 12:23 pm | #33 | |
Octode
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Re: Baird TR1 Reel to Reel Coil Connections
Quote:
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10th Sep 2021, 1:13 pm | #34 |
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Re: Baird TR1 Reel to Reel Coil Connections
A lot of tension arm damping was (and still is) done with air dashpots or the infuriating little bellows on the Philips Pro machines - Kilopoise being a synthetic product, I'm not sure when it first appeared.
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13th Sep 2021, 11:43 am | #35 |
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Re: Baird TR1 Reel to Reel Coil Connections
Managed to free up the tape tension arm for the reverse motor without having to remove it.
Operation of the Reverse Play/Record/Fast buttons now are not so stiff. The Forward Play/Record/Fast buttons are also not so stiff (currently not connected to the Forward tape tension arm as not yet refitted). The buttons even though less stiff, were still somewhat stiff, so have cleaned and lubricated all the associated Button mechanisms which has improved things. David |