Phillips Tape Deck Repair (For Spectrum & ZX81)

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A short video covering an essential pickup so I could load old tapes on the Spectrum and ZX81.
MsMadLemon's channel as mentioned in the video:- / @msmadlemon
#gadgetuk164 #repair #msmadlemon

[@GadgetUK164]

MsMadLemon's Channel:- kzbin.info/door/SlMemxuBOFu6Rz_Al02nHQ?pbjreload=10

[@MsMadLemon]

Thanks so much for the great shoutout! I appreciate that! :oD This is quite simple inside compared to others, normally even these mono/computer tape decks, there is a transformer to connect to the mains, this is the first i’ve seen one that’s only battery/DC jack! For sure a modern one! Speaking of which what was with the DC jack lol very cleanly desoldered if soldered in at all? this thing seems to have been used for spare parts or something! btw what was the alternative to IPA for the heads? I heard you say something like Plastix? i’ve never heard of this.

[@MsMadLemon]

From what i’ev heard, on the zx81 the ULA used the same pin for video out as the tape data audio in which causes those lines everytime you load…it was unintentional, and they later made it a feature in the zx spectrum so indicate loading apparently :o)

[@GadgetUK164]

You're welcome! I will give you another shoutout when I get back to some C64 videos I have to do soon. The DC jack just lost its connection, probably from being wobbled with regular use etc. It was VERY annoying finding it stuck to the speaker lol.... For cleaning disk drive heads I found that IPA doesn't remove all contaminants that have been rubbed into the surface of the heads (they can be really persistant). I used Meguiars PlastX - which is a plastic polish. It works miracles on heads that seem to be beyond. Often if you inspect the head really closely with magnification you can see particals smeared onto the head that IPA will not shift.

[@GadgetUK164]

I didn't know that =D

[@robbyxp1]

Ahh, blu-tac. Essential electronics component for a ZX81 16K RAM pack. Lovely video.

[@GadgetUK164]

Hehehe - yes, ironically I think that fix was suggested by Sinclair themselves. I remember seeing it in "Micro Men" the BBC TV film about Sinclair and Acorn - worth watching if you haven't already, and available to watch on YT.

[@Four_X]

The best way to align an azimuth is to use a 15KHz azimuth alignment tone tape and a scope to see when the pickup signal coming from the head is at its maximum peak-to-peak amplitude, if you do this you'll always get it dead nuts on. Our fellow KZbinr Jan Beta used a scope to align a Commodore C2N Datasette in one of his videos however he used a standard audio tape when he did his alignment not a 15KHz azimuth alignment tone tape. It's best to use a 15KHz azimuth alignment tone tape as it makes life a lot easier as the signal isn't bouncing all over the shop, because it's a constant tone and not fluctuating like standard audio would it makes it easier when your tying to adjust it and find where it's maximum peak-to-peak amplitude is on a scope. It's not hard to create your own 15KHz tone tape, the simple way is to use a audio editing program like Sony Sound Forge Pro to generate a 15KHz sine wave and save it as a .wav file, you can then output it though your PC's soundcard to a known good tape deck and a good quality tape and you've got yourself a very nice 15KHz azimuth alignment tone tape, you'll get those pesky spectrum, C64 or any other tape player working at peak performance in no time.

[@GadgetUK164]

I've adjusted a lot of Azimuths by ear for Spectrum loading! Trust me, if you get a known well recorded tape you can do it purely by ear and get it absolutely spot on! It really is just a case of listening for the clearest sound.

[@GadgetUK164]

BTW - Fully aware of the proper way to adjust it, that just takes more time compared to the way I started doing it. Plus, with the Spectrum you will find that not all tapes are aligned the same. There's actually a need to learn to adjust it by ear to get those hard to load tapes loading. I remember adjusting my azimuth at least once a week to account for the variations between some of the tapes I owned (not on copied tapes but commercial releases!) My friend Andrew had adjusted his azimuth so much the slot was clearly worn on his Spectrum lol.

[@StRoRo]

Well power socket on the speaker made my chuckle

[@GadgetUK164]

LOL! I can assure you it didn't make me chuckle!!! I am still bealing about it now...

[@bwack]

The shy power jack clinged to the speaker magnet. :) Perhaps a low Vf diode on the battery leads to protect batteries from destruction incase of plugin in power with batteries inserted. Funny the cassette reads Living in Norway :)

[@GadgetUK164]

Good idea =D I will do that! Haha @ the cassette - yes, its a learn to speak Norwegian tape =D

[@missionpassed4584]

Why am I so addicted to this stuff? lol

[@GadgetUK164]

Haha, me too lol! More interesting than a lot of modern stuff I guess!

[@IanScottJohnston]

For info, the DC jack looks to be same as I use one one of my products: Farnell 2472145 & 224911

[@GadgetUK164]

Thanks =D

[@RetroJay1974]

I just snagged one of these tape deck units, noticed the capstan/pinch roller is missing the rubber tyre? I need to find one to replace it. No idea where to start :(

[@GadgetUK164]

Sorry for my slow reply here! I would just hit eBay and search for "similar" parts - eg. from another tape deck. Sometimes you can find tyre and belt kits - of which one might fit.

[@VectrexRoli]

You can never have enough one of those old tape decks. It is impossible to find modern ones, good enough to load old ZX 81 tapes even if you adjust the head and everything.

[@GadgetUK164]

Yeah, the belts and rollers are the biggest problem! Good to have spares tape decks!

[@andrewlittleboy8532]

Platenclene rubber cleaner is very good for pinch rollers and belts.

[@GadgetUK164]

Thanks! Will give that a try!

[@zenmaster24]

does the spectrum just use audio signals to load the game? could you use something like a walkman with its headphone out? is this just for nostalgic reasons, or is it a compatible tape player with the spectrum and zx81?

[@Neffers_UK]

Ok, quick run down for you... There's multi-load games, you often see games that when loaded say "press pause (or stop) on tape" (play a level, "press play on tape"), this was the poor mans way of loading games and let the computer free up ram to load the next level in. Micros such as the C64 had control of the playback of the tape, it would handle this automatically, this is why a lot of micros used the "Remote" jack, instead of it being used for transcribers it was used for computers :) Yes, you can use any playback device, but it's not ideal. Impedance is a big thing also. That you will have to research yourself if you are really interested. Basically the listening bit of the Spectrum would not tally with some modern devices outputs. It's finicky.

[@GadgetUK164]

Yes, its just an audio signal - unlike the C64 which has some digital conversion done by the tape deck. You could just use a walkman - the probem with walkmans is they are typically very well worn (one of the most popular ways people used to listen to cassette), and they tend to be a bit less hard wearing due to the size of the components inside etc. Provided the walkman outputs a high enough volume level via the headphone jack, it should work fine. I've used a CD based walkman before now to load Spectrum games. Just have to convert .tap files to .wav files and then burn to CD. But most CD walkmans have a volume limit (like iPods did) whereby the volume isn't quite as loud as it needs to be.

[@zenmaster24]

ah - i was going to say, why not just use something like a phone or cheap ipod :) if the volume isnt loud enough, would a small headphone amp work?

[@jasejj]

I used a nasty Matsui personal stereo to load games into my Speccy back in the 80s, and connected it via a home-made 3.5mm to DIN jack to copy games to my handed-down Philips music centre as my dad wouldn't allow me to touch the proper hi-fi downstairs. It worked just fine - generally with a Spectrum the worse the tape deck the higher the probability of it working correctly IME.

[@jasejj]

zen There are apps available today that will take a tape image off the internet and convert them to fast-loading MP3 files that can be used with just about any audio player.

[@trigg99]

we were so patient in the 80s

[@GadgetUK164]

LOL! We certainly were! If I had been patient I might have found that connector before commiting to fitting a new larger connector! The hour and a half it took to get the volume level just right was very nostalgic - in a bad way lol. Straight afterwards I went looking for SD card solutions for the ZX81 :o)

[@trigg99]

lol

[@trigg99]

I remember having Daley Thompson for the spectrum 128 and it took 45 minutes to load lol

[@GadgetUK164]

Haha =D

[@Bylga]

GadgetUK164 mixtape comming out soon.

[@GadgetUK164]

Hahaha =D

[@Neffers_UK]

Just wanna pull you up on something cause I can (I'm only havin a laugh - nothing serious) The rubber wheel is called a pinch roller and the metal axle it pushes the tape against is the capstan. www.cse.iitk.ac.in/users/amit/courses/371/adarsh/teces_192.gif Another nice vid, thank you for taking the time to do these vids, they shall be treasured one day.

[@GadgetUK164]

Yes yes lol - laugh away!!! I did used to call it the pinch roller, then 30 years happened and suddenly my vocab was had a senior moment and whilst I knew the capstan was the metal pin (connected to the capstan motor), all I could think to call it was the capstan roller lol. Thanks for clarifying!!!

[@osgeld]

place a diode in series so the + of the battery cant be fed by the DC jack, done

[@GadgetUK164]

Great idea =D Problem solved!

[@Plan-C]

Good skills. Lol, the part needed was hiding all along and only shows up at the end when you don't need it anymore. Typical😠

[@GadgetUK164]

Thanks! yeah, annoying lol - really annoying! It could have been perfect, instead it ended up with a larger jack (but more robust I guess).

[@DaveCurran]

Internal RAM is the way to go on the ZX81, avoid having to superglue the RAM pack on. blog.tynemouthsoftware.co.uk/2014/07/zx81-internal-16k-ram.html

[@GadgetUK164]

Thanks, I will give that mod a go =D Just need to source a 65526 of the right DIP type.

[@DaveCurran]

I get them from RS and Digikey. It now seems to be easier to get the 600mil wide DIP versions than the thin 300mil versions which used to be more widely available. e.g. uk.rs-online.com/web/p/sram-memory-chips/1257523/

[@GadgetUK164]

Thanks Dave =D I will put an order in at some point soon!

[@DaveCurran]

This reminded me I had meant to write up an alternate version of this modification which does not involve cutting tracks. Now done: blog.tynemouthsoftware.co.uk/2017/10/zx81-internal-16k-ram-reversible-version.html

[@GadgetUK164]

Awesome!!!! =D