2 June 2024

I blame George.

As teenagers, some of us would visit George and listen to music on his Grundig tape recorder - Otis Redding and Cat Stevens featured often.

There were fewer choices for listening to recorded music in those days, the main alternatives being a transistor radio or record player.

In 1967 the BBC launched Radio 1 to broadcast 'light music', which was popular for their Top 20 chart count down each Sunday. However I generally preferred the coverage of Radios Luxembourg, Nordsee International and Caroline.

As for record players, I was given a portable version by my Aunty Jean. This came with a 78rpm Elvis Presley record featuring Hound Dog on one side and Don't be Cruel on the other. In 1963 I bought my first single, I Want To Hold Your Hand by the Beatles.

I recently compiled videos of some of my favourites from that era, in memory of those no longer with us …

(Leonard Cohen lived on the Greek island of Hydra in the 60s - we didn't make it until the 70s)

When putting together an Otis Redding video I remembered hearing Otis on George's Grundig, which led me to browsing eBay in search of my past …

6 June 2024

eBay

Have a look on eBay and find a vintage* Grundig TK 18L being sold by St Peter and St James Hospice Shop. The item is listed as 'untested' and even if it's a complete turkey a charity will have benefitted.

*A vintage collectible should be at least 50 years old, so while making me feel old it is a correct description of this item.

QXL

eBay now dominates the online auction space, but that wasn't always the case. The first dedicated auction websites appeared in 1995, namely Onsale.com (founded by Jerry Kaplan) followed a few months later by eBay.com (Pierre Omidyar).

However eBay did not serve the UK until 1999, and in the interim a British competitor arose. QXL (ie 'QuickSell') was founded in 1997 by journalist Tim Jackson. QXL proved popular and upon flotation it briefly hit a £2bn valuation. However it was no match for eBay and despite surviving the dot com crash it gradually withered away.

My email archive shows that I bought a Thomson DVD player through QXL in October 1999 and a Umax 1220U USB Scanner a few months later.

7 June 2024

Returning to eBay, the auction ends and I am the proud owner of an untested vintage tape recorder.

The strike price is £35, which is less than the £41 these sold for in the mid-1960s. Using historical UK inflation rates that price is equivalent to £1,120 today. This seems quite steep. However an Austin Mini cost £470 in 1965, which using the same inflation figures equates to around £12,500 today. This is not too far off a new Dacia Sandero at £13,795, so perhaps those inflation figures are reasonable.

16 June 2024

Drive over to the Argos collection point in Yeovil and pick up the eBay parcel. There is a dedicated counter for this and the process is fast and smooth.

The Grundig is well packed and once extracted appears in good condition. It's hopefully not too good, otherwise I won't have a project!

17 June 2024

Do some sniffing around and find a review of the TK18 from October 1963. It concludes that the model performed as well as the many other Grundig machines the reviewer had tested and should quite satisfy those who prefer the minimum amount of knob twiddling and button pushing.

Rather faint praise!

The review is actually for the TK18 and not my TK18L, although I have yet to find out the difference. The picture in the article differs from mine, but that may be due to being a different model year.

Also locate a service sheet for the model, including a wiring schematic. Close inspection of this finds reference to a humdinger. This is quite literally a means of reducing hum by eliminating earth loops when there is more than one main route to earth - one of these will be causing the hum.

That's a new meaning for humdinger to me, so the electrics won't be as striking or extraordinary as first expected.

18 June 2024

So what about Grundig?

According to Wikipedia it was founded by Max Grundig in 1945 as a German consumer electronic company. It later grew to be a world-leading manufacturer of radio, TV, recording and other electronic equipment.

Grundig developed a portable tape recorder in the 1950s and in 1960 opened a plant to manufacture tape recorders in Belfast. The factory was closed with the loss of around 1,000 jobs in 1980.

Grundig was acquired by Philips in 1993, and subsequently a Turkish firm in 2007.

25 September 2024

Enough of the diversions, it's been a few months now and it's time to see what I've taken on.

Remove the tape recorder rear cover by unscrewing the four rubber feet. The interior appears quite clean, with no obvious wear and tear. Removing the metal panel reveals a clean, dust-free circuit board.

There is a label possibly bearing the model and serial numbers, but there are apparently no Grundig factory records against which to check these.

Fuse Assembly

There are three fuse holders and two glass cartridge fuses, which warrant further attention.

The main fuse is marked as F02B 4/10A 250v (ie 400mA). It is used to select either a 210v or 230v operating voltage, and a transparent panel in the case allows this to be checked externally. No country appears to use 210 volt mains power, although the UK has used various standards in the past and some areas transitioned from 210v to 240v in the 1960s.

The second is an HT fuse marked as F02B 150mA.

Both fuses are surge-resisting (also known as slow-blow, time-delay or time-lag fuses). These can withstand a temporary overload such as a surge on powering up capacitors, motors or transformers.

Power flex

The power flex is quite tatty and the plug fuse has a rather high 13 amp rating. The flex is probably original as it has the pre-1971 colour scheme of red live, black neutral and plain green earth.

Pop down to Harts of Stur and obtain a replacement flex of similar length and girth. The flex is marked as 3 x 0.5, so each conductor has a 0.5mm² cross-section. Reduce the fuse rating correspondingly to 3 amps.

Front Cover

Remove the front cover by removing the four securing screws and easing past the piano keys. Note for re-assembly: the top two screws have a different design to the lower ones, and the lower ones differ in length.

Removal reveals a rather dusty and grubby interior which will need some attention. However at first glance the drive belts appear sound and there are no glaring mechanical issues.

Everything Vintage

I learned two things from Everything Vintage that won't be news to those who actually know about these machines. I cheekily reproduce them almost verbatim: First, these tape recorders work like cassette recorders did - the audio is recorded on the top half of the tape only, so the tape can be turned over for the other half to be recorded.

Second, the tape is not pulled through by the receiving reel - it is actually fed by a clutch via a soft felt pad. The take-up reel rotates merely to gather up the tape.

Valves

The machine apparently has 4 valves: ECC81, EF83, EF86 and ECL86. The top of one of these is visible, probably the ECL86 as it is about 72mm tall (excluding pins) compared with 49mm for the others.

Fortunately, replacement valves are still available. Three of these for instance can be acquired from vintage electronics specialist Langrex for prices upwards from £20. The missing EF83 appears to be more elusive, although at the time of writing there is an example on eBay for £25.

Hopefully all my valves will glow and function nicely.

9 October 2024

Time to accessorize, and today sees the arrival of a matching Grundig GDM18 microphone. This was acquired through eBay for £7. It was described as 'For parts or not working'. However it looks in good condition, and hopefully it is untested only because the vendor was unable to do so. We'll see.

13 October 2024

Cleaning

Remove the fluff and dust with some cotton wool buds. Use the buds with some meths to clean the pressure Pad and the pinch roller wheel.

Remove the large metal rings from each clutch housing to expose the felt clutch inserts and clean these with meths - they actually looked in good condition.

Mechanicals

An inspection of the moving parts shows the three drive belts to be intact and operational.

Load the tape reels and switch the player on. Was surprised that the motor starts up as soon as the unit is switched on, but this makes sense as the heavy flywheel needs to be spinning fully so that tapes reach play speed immediately.

However there are two issues which may explain its disposal by the previous owner.

The first is that the tape feed mechanism does not retract fully when play is stopped. This appeared to be stiffness in the pivot of the arm that interacts with the Play key. Removal of the circlip shows this not to be the case, and the problem is tracked down to resistance in the tongued support arm near the pinch roller wheel.

The second issue is that the Play key does not lock in place when depressed - it should require the Stop key to release it. The Stop key operates a long lever across the set to access the left hand keys, and a short plate for the right hand keys. The Play key has a notch which engages with this plate, but years of use have resulted in a groove worn on the plate edge which stops the key notch engaging. There is no easy way to repair the plate, so try to resolve the problem by deepening the notch on the key itself.

14 October 2024

Test the modified Play key - this takes a few cycles of trial and error until the Play key remains depressed.

The key now doesn't open quite as far, which has a knock-on effect on three other mechanisms. First, the lever that pushes the pinch roller into play does not move far enough. Second, the electrical contacts don't open far enough for the full volume to be heard. Lastly, as the right and left hand release plates now have different arcs of movement, the rewind key no longer locks in use. There is no easy fix for this, and future users will need to keep their finger on the rewind key.

Extend the travel in the pinch roller lever by slightly bending the lower tab on the Play key. Also try bending the lower tab of the pinch roller operating lever. Open the loop in the contacts spring slightly to ensure that electrical contact is made. Using these tweaks the tape recorder plays at an acceptable volume.

There is a bit of distortion, especially as the left hand reel unloads, possibly because the spindle needs slight easing.

The tape itself consists of early 1970 songs, seemingly recorded from the radio. It's not known whether the tape originated with the recorder itself, but its age suggests that it was.

25 October 2024

Perhaps because of Chicory Tip's upbeat tempo, the Play key refuses to remain depressed. This is sub-optimal behaviour for the user.

The cause is tracked down to the Stop key preventing the lock plate from rotating high enough to meet the new Play key profile.

The Stop key itself is therefore re-profiled to provide the necessary clearance.

It is about this time that I notice a feature common to many of my projects; a left-over component.

This small part (as pictured) suddenly appeared, and despite close inspection of my photos I fail to identify its source. It is possible that it appeared when turning the unit over to release a fallen nut (of which further). So reader, if you know its purpose please drop me a line!

26 October 2024

Bending the operator lever was not an exact science, nor was it neat. The decision was therefore made to effect a tidier solution, requiring removal of the pinch roller operating lever.

I had hoped that the lever spindle was screwed into a threaded hole, or perhaps a captive nut, but no such luck. The unsecured nut drops into the innards, eliciting a sharp intake of breath.

In a twist of fate the nut remains visible next to the valve, and I manage to retrieve it using the dual expedients of a cotton wool bud and a small dob of Dorset honey. The honey is from David Throw of Sturminster Newton, but it is likely that any other set honey would suffice.

The short lever from the Play key slots into the operating lever, with the end kinked to keep it in place. I unkink the end and drill a small hole through the end tab to take a retaining circlip. In the event I do not have a slim enough circlip, but use a small panel pin instead. Now that the small lever is removable, its travel can be more easily adjusted in the future.

27 October 2024

Now for the difficult part, screwing the lever spindle back onto the base. Somehow the nut needs to be positioned under the mounting via a small gap adjoining the valve. Human fingers are not built for that.

Something is required that will offer the nut up to the underside of the hole and hold it in place as the spindle is tightened up. In the absence of a small flat spanner that can be bent at one end, the decision is made to fabricate one. This is done with a suitable item from my metal offcuts collection, as illustrated. After much trial and effort the miscreant nut is once more tightly joined to the spindle and order is resumed.

With everything re-assembled the irony is that fine tuning is not even necessary, and the Play button engages straightaway. However it is good to know that any future adjustments will be a lot easier to make.

For the next test, Elton John agrees to reprise his 1972 hit Rocket Man. Although the playback speed is sub-optimal by modern standards, the tune is recognisably that of Sir Elton Hercules John.

Which just leaves me to try out the recording function using that eBay microphone …

Fortunately the microphone works, although not via the microphone socket. According to the wiring diagram, the microphone socket (marked with an Omega symbol) is for a 2mV - 45mV sensitivity whereas I used the radio/gramophone input socket, specified as 100mV - 2V.

The track was played on my PC, with the microphone dangling in front of the speakers. The age-appropriate wavering of sound transports me back to those Suffolk Street days.

31 October 2024

So that's it - I've been transported back half a century to George's front room at Suffolk Street in Cheltenham.

At the time Otis wrote this song JFK was US President, tragically assassinated a year later. As of today, the US electorate is making a stark presidential choice between Donald Trump and Kamala Harris.

By now you will know how that turned out …