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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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Old 9th Nov 2017, 5:10 pm   #1
DavidTD6
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Default Marconiphone Reel to Reel 4218

I've had one of these for a number of years, purchased very cheaply from eBay. Only one internal speaker seems to work, although this isn't a major problem as I always have it connected up to an amp via the line out.

One question I have though is why, when I make a new recording on Side 1 of a tape is it faintly audible on Side 2 (obviously playing backwards), so much so that I can really only record on one side of a tape if I don't want the other side to bleed through. The head alignment appears to be ok, so it's a bit of a puzzle. This machine works really perfectly apart from that - the sound quality is amazing for such an old piece of kit.

I'm also wondering if the Track Transfer button may be faulty which is causing this issue? I've no idea what this feature actually does or is for and as I have no instruction manual or can find anything about it online, I'm hoping someone may be able to assist here.
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Old 9th Nov 2017, 6:03 pm   #2
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Default Re: Marconiphone Reel to Reel 4218

Hi David and welcome.
It appears you are using a tape that has been recorded on before and that the original recording is half-track. If that's right, do you know the age of the tape? Newer tapes have a magnetically harder formulation and it may be that your machine doesn't have the erase power to fully wipe it before the new recording goes on. An older tape may be more suitable.

But maybe the erase head is just mucky.
Graham
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Old 9th Nov 2017, 8:27 pm   #3
AndiiT
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Default Re: Marconiphone Reel to Reel 4218

Hi, it sounds like you may be trying to playback a two track tape which has been erased by a four-track machine, I'm unable to find the original post which details this but have enclosed some information from P.Springs "Tape Recorders" book which might explain things in more detail that I can.

Regards

Andrew
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Old 9th Nov 2017, 8:41 pm   #4
dave walsh
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Default Re: Marconiphone Reel to Reel 4218

Handy visual info there from Andrew. What does it say at the track transfer button David? I was assuming a half [2] track head as well but if your buttona are marked 1-3 2-4 it will be a quarter [4] track machine. If it is a 2 track recorder though the ttb may be some way of bouncing recorded sound across. As you have gathered, the age of the tape and misalignment can be other factors in all this. PS just found one 2012 thread re a power problem with a 4218 on here plus an image on another site [fairly modern/semi-pro domestic/flip switches/ one meters and what definetely looks like track switches]. Seems to be a mono recorder but it's a poor photo. Two internal speakers-stereo or mono. Am I looking at two versions?

Dave W

Last edited by dave walsh; 9th Nov 2017 at 9:04 pm.
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Old 9th Nov 2017, 10:36 pm   #5
AndiiT
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Default Re: Marconiphone Reel to Reel 4218

Hi, from the look of a picture I found on the internet the Marconiphone 4218 is a four - track 3 speed stereo machine.
If it's the same as the Ferguson variant that passed my way some time ago the machine will have two rectangular buttons marked 1-4 and 2-3 for individual mono track recording, or stereo recording when both buttons are depressed.

An unusual feature of this machine is that there are two separate transport buttons for playback, one for track 1-4 and the other for track 2-3; if the OP is depressing both buttons when playing back a two - track tape on this machine both tracks will be heard but side two of the tape will play backwards.

Hope this helps

Andrew
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Old 9th Nov 2017, 10:59 pm   #6
dave walsh
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Default Re: Marconiphone Reel to Reel 4218

Further complications Andy! I said it was stereo at first but then "erased" that later after becoming confused. Never seen that separate playback configuration before

Dave W
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Old 11th Nov 2017, 2:46 pm   #7
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Default Re: Marconiphone Reel to Reel 4218

An annoying feature of this machine is that when playing back in mono only one channel of the radio out socket is used - thus it will only play through one channel of an attached stereo amplifier.

I have modified mine to take the signal from the high end of the playback volume control and sent it through an attenuator (divide by two, made from two 33k Ohm resistors in series). This gives a good line out on both channels. I removed the remote socket at the back and used a 7 pin din socket wired to carry this signal on pins 3/5 together with the normal radio input on pins 1,4 and gnd on pin 3. The remaining two pins were used for the tape pause and tape stop functions. This means that normal 5 pin din leads can be used to connect to an amplifier that incorporate a series resister. In addition it preserves the remote control function.

My amplifier does not have a mono switch.

I also built a switch box to automatically switch between two tape recorders - but that is another story.
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Old 15th Nov 2017, 12:24 pm   #8
DavidTD6
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Default Re: Marconiphone Reel to Reel 4218

Thanks for all the replies. I have an ex BBC Weircliffe Bulk Eraser and have used this to completely erase any tape I'm going to be recording onto. The machine I have is the 4 track stereo version yes and correct, it has the two play buttons - one for left (1:4) the other for right (2:3) playback. Also the two red record buttons makred the same, so they are both pushed in for a stereo recording. (I never record in mono any longer). Tapes recorded on other 4 track machines seem to play back ok - although most of the old recordings I have from other machines are just mono, so I don't think it's an issue with playback, but any new recordings I make in stereo are faintly audible on the other side. I mean faintly - imagine living above or next door to a nightclub or disco and all your hear is the faint bass - this is what I hear coming through on the other side of the tape when I've recorded on one side - very puzzling.
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Old 16th Nov 2017, 4:04 pm   #9
AndiiT
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Default Re: Marconiphone Reel to Reel 4218

Quote:
Originally Posted by DavidTD6 View Post
..... any new recordings I make in stereo are faintly audible on the other side......
Hi again, it sounds like the heads may be slightly out of alignment but finding a suitable alignment tape these days isn't going to be easy.
The other option is a degree of "print through" although I can't see how that would be the case as print through normally happens after tapes have been stored for some time.

Andrew
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Old 16th Nov 2017, 4:33 pm   #10
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Default Re: Marconiphone Reel to Reel 4218

As said, could be tape path/head that's out, the top of the tape should be "only just" above the top head, too much and the guard band will be reduced if I remember rightly. (been a long time)

Lawrence.
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Old 21st Nov 2017, 1:11 pm   #11
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Default Re: Marconiphone Reel to Reel 4218

There used to be various liquids which would act as 'magnetic developers' so that the actual track layout could be seen. I've never seen one of these myself, apparently they were some form of fine iron powder suspended in some form of solution, so that the iron powder orients itself according to the magnetism on the tape. Tandberg mentions the brand name 'Magna-See' in their service manuals.

I believe Scotch also had a device for observing tracks, essentially it looked like a looking glass, physically it was made up of a small circular container with a thin membrane on one side, the contained filled with fine iron filings, with the same principle of orienting themselves according to the magnetism when placed on magnetic tape.

Sorry to go to lengths for these now obsolete and most likely unobtainable devices, but this sounded like a clear case for which they would have been useful.

(On this subject I once bought a bottle of magnetite powder, intending to do some experiments; I remember mixing it with alcohol to see if that would be useful but couldn't get any useful pattern from the tape, instead the magnetite simply lumped up and didn't do anything. Perhaps a different carrier fluid would have been more successful).
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Old 21st Nov 2017, 4:56 pm   #12
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Default Re: Marconiphone Reel to Reel 4218

It appear that such magnetic developers are still made, a google search will find a couple of companies that make them. I can't find anyone who sells it (or ships it) to the UK, if anyone knows of such an organisation I am looking for it too.
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Old 21st Nov 2017, 6:29 pm   #13
Ted Kendall
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Default Re: Marconiphone Reel to Reel 4218

The 3M viewer is now sold by Arnold, I think, from Switzerland. There's an expensive Japanese one whose name I forget for the moment but no matter - avoid.
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