TK140 Deluxe - recording sporadic

[RobIAOTU]

I have a TK140. Playback of pre-recorded tapes is fine, but when I'm coming to record I'm getting, usually, no results whether I record 1-2, D, or 3-4. I've got a 5 pin female to stereo Jack cable, and it works once in a blue moon. I don't know what I'm doing wrong, but sometimes I'll think I'm recording 1-2, and it'll only playback 3-4. Also, I hear no playback when the machine is "recording" - however, when I am on "pause", without record held in, I can hear the input signal.

I don't know what to do, and my sanity is being tested.

Please help. I know it must be working, as it has, about twice, for no apparent reason. Nor do I know exactly what I did to get it to work, in terms of setup. Help, please, someone help.

[DOFFERY]

Just to start with , does the machine play back on 1/2 & 3/4 OK?

There is no facility for recording on "D" this is purely for playback.

Have you tried the simple record test on either track with a mike?

Start at the beginning with the playback .

There are many possible faults on this machine, mainly the many switching items.

There should be no monitor of the input when switched to record (apart from headphone), as the output valve (pentode) doubles as the oscilllator on record.

The track switching unit is always a problem as indeed is the record/play switch, they may be dirty & require cleaning.

Colin.

[RobIAOTU]

Hi Colin,

Thanks for your reply. I have a lot of tapes, each playback on 1-2 & 3-4 - they playback really clean, but it's recording that seems to be the issue, but in a sporadic nature - sometimes works, most of the time not

I'm going to have another go tonight, and try really basic tests - as I have done. However, when I have managed to record - I don't know how I did it..then try again, and it won't work.

For example, if I select 1-2 or 3-4 will it only record on to that side?

Thank you for the heads up on there being no monitor to hear what's being recorded. I've since posting read some threads where the tone wheel doubles up as the recording level, so I'd sussed there may not be a monitor.

When you say the record & play switch cleaning, do you mean the dead - or the physical switches?

I know to hold in the record, then start which initiated the playing - but the (dot) on the wheel, what is that for - and which input is best for recording?

Thanks Colin.

[ben]

The dot on the function knob is just a 'pause' mode between modes.

There could be a few causes:
-faulty cable
-dirty contacts in socket
-dirty contacts on rec-pb internal mode switch

I would imagine that the middle socket on the rear is Ok for line level. Try connecting a microphone to the one on the top plate and see if it records well. If so, that elimnates most if not all the circuitry!

edit: looking again at the sockets, the ones at the rear: the wavy lines was usually an output, and the middle one I mentioned before looks like a headphone /monitor output. Not sure if some of the pins are also used as an input, perhaps someone with the manual could confirm. It has been decades sicne I've used one of these models.
The top deck socket is definitely used as a mic input, maybe line level also...which one have you been using?

[RobIAOTU]

Thanks for the reply Ben - up to now I have been using the top socket as an output with no problems, and the back two don't give me an output signal - any recording that has happened has been via the wavy lines, but it's been either, sporadic, low quality or not happened.

I had a message off someone on here last night who advised the top socket also being the recording input, however when testing, nothing comes through.

Cables are new, of which I've got 2, but they're not dismantle-able, which is annoying, as I've since learnt different pins have different functions.

Today I'll be testing all day, and will update.

[ben]

The wavy lines one , on the schematic I have, seems to be a low level playback output for stereo playback or for slide synchronizer etc. I don't know how you managed to get any recording done via that.

The key seems to be the top one. Pins one and three are record and playback with a common ground. Yo umight need to get a DIN plug you can open, put the unit in record mode, and touch those pins to see if the meter moves.Then solder your input cable accordingly.

[RobIAOTU]

Cheers Ben, I felt that might be the case - just worries me a product would be sold with all 5 pins, yet they're only wired up for output, and not input!! Issue for me being, I've purchased plastic encased din plugs, so I can't open them up to sneak a look - but I feel this may be the issue - given the output is fine, and there has been recording on occasions (so in terms of mechanics, the system seems fine) - it's just the ****** cables!!!

When you say meter? Do you mean the green light, as when the recording mode is locked in, the light remains a solid green?

I can see why DIN fell by the wayside :p

Cheers, Rob

[ben]

The light in the 'magic eye' should be two lighter portions at the right and left hand sides, which meet in the middle as the signal increases. If they are permanently engaged, then you have a fault, or have the vol/rec level up too high. What happens when you unplug the cable?

[RobIAOTU]

When the cable is unplugged they are quite far apart. When the signal input increases they get closer together, and if I change the volume control on the machine itself the levels go down. I'm just having issue with actually recording now.

With your help, and of others, I've fathomed the input, tested that the machine is reviving the signal (as the lights move), it's just recording now.

Current process;

Select 1-2>stop>hold record>pause<green lights>Start>stop>RW> nothing is there!! The tape is loaded the same way for playback, so I'm really stuck now.

Cheers Ben.,

[ben]

It seesm then that the machine is receiving the input signal OK, if the meter responds correctly.

I presume you have cleaned the heads and tape path with fluid/isopropyl alcohol ?

Does it erase old recordings OK?

[DOFFERY]

What kind of signal are you trying to record , audio, test tone or If audio you will get fluctuating movement of the magic eye. Forget the sockets at rear of machine.

Is the tape the right way round, only one side is recordable.

As Ben mentioned above, heads etc. faiing that you are down to problems in the cct.

Colin.

[RobIAOTU]

Haven't tried wiping old recordings yet Ben, good idea - I had considered it, but I can't bring myself to wipe anything!!!! I've cleaned out all of the dust and hair - as for the heads themselves, no. Another thing for the to-do.

I'm just trying to record a line-in from an amplifier. The signal seems to be received, as the green eyes are moving in pace time with the signal.

[ben]

You'd probably do well to get some fresh tape /sacrificial tape off ebay or somewhere, not only would that eliminate the tape you're using as the culprit but also you could erase unimportant material.

[Tractorfan]

Hi,
I'm having similar fun and games with a TK149 which plays back back very well, but won't reliably record. It's good innit?
If you pm me, I have a couple of 3" reels of tape you can have to play around with for the price of the postage.
Cheers, Pete.

[RobIAOTU]

Thanks for the offer Pete - but I have hours and hours and hours and metres and metres of old tape.

Ben - I tried the test of recording on to a tape with music on - or the lottery results being read out on the radio to be precise - and while there was an input signal being picked up by the green eye, when I played back there was just blank tape, and the lottery results were gone.

So now I'm confused - the signal is going through the green eye, yet the playback was blank - although the tape was wiped.

Any ideas for what to do next?

[DOFFERY]

So it did "erase" the music on the tape Do you have a test meter & any knowledge of circuits?

Colin

[Welsh Anorak]

Hi there
So we can assume the machine is erasing what's on the tape, and it plays back OK.
Now is the 'magic eye' responding to the input? By that I mean if you feed music into the machine does it fluctuate like a meter would (complete with its mirror image). Bit difficult to explain, I admit. Now as you increse the input volume the two sides of the meter should 'crash' in the middle indicating overload; conversely each side should stay near to home when the level is reduced.
Assuming this is the case, I would suspect you have switching faults. With the machine off and in Stop, work the record button up and down vigorously. Similarly with the track switching buttons. This will clean the switches and, even if they need proper cleaning with switch cleaner later, this should help.