REAL radios glow without smoke.
The SAJA Mk5 (Export) was designed in 1957 (schematic drawn date) in West Germany, and this example was purchased by my parents in 1959, from 'Dickinsons of Pall Mall'. Strange, still have the receipt(!) but I think the warranty is kaput by now. This machine has done a heap of work and has been in storage for quite a few years now, so it has come to pass that it needs to be reborn.
This is a 2 speed machine, 3 3/4ips or 7 1/2ips selected by the red button at the top-left. Push and turn to lock it into 7 1/2, release for 3 3/4. The strange part is the non-standard maximum spool size of 5 3/4". The machine is a 2-track mono with a maximum of 5w audio output through the 2 front mounted speakers.
The electronics of the machine consist of selenium bridge B+ rectifier and 5 tubes. EL84 output, ECC81 Pre-Amp, EF86 Head amp, EL95 Erase oscillator and an EM85 record level display 'Magic Eye'. The Tell-Tale lamps on the front are run from the 6.3vAC filament line, and tell the operator what mode the machine is in. There is 1 motor, driven from the 150v transformer tap. A little puzzled why the 240v transformer tap is not fitted. It is on the selecter panel, but there are no connections behind it to the transformer, but the others taps are connected as indicated maxing out at 220v. Whilst this will work for the 240v supply around here, the transformer will run hotter, and tube life will suffer a little. I have a 240-220v buck style transformer, so I will run the unit from this to help it along.
If you have a look at the picture above for the video, you might notice that the machine in the picture is not the one in the video... ah-haaa... The machine in the picture is the original one from the family, but it needed an output transformer and I did not have a suitable replacement in the junkbox. One afternoon I happened to be trolling through the acres of junk on evilbay, and noticed an identical machine on sale from a second hand store in Melbourne. It was listed as not working, parts only, and parts are what I needed. The price was reasonable so I parted with some coin and got the machine. When it arrived it was in very good cosmetic condition, but didn't work. Oh, no... I can't bring myself to scrap it for parts so I now have two machines. The evilbay one had a shorted B+ filter cap and some leaking capacitors so it got the same treatment as the first machine.. Total recap and resistor replacement saw this one spring back to life and sounded quite good in fact. That is the machine in the video. Meanwhile, this machine was still in need of the transformer, so I bit the bullet and pulled it apart. Measured the wire diameter and turns layouts as I carefully unwound the wire. Got some new wire and rewound the coils. Put back together and reinstalled, it looks original as the outer paper layer was retained and reused to cover the new windings. Powered on and it too came back to life again. Ok, now I have two working, restored machines and yes, they both sound great for their age... I will add another video of the two in due course.. The gallery below depicts some of the work on both machines, but I forgot to get some pictures of the transformer rewind job.
For those interested, look at the tell-tale panel on the picture (complete) and the one in the video (damaged).. Did you notice?? I bet not.. LOL
(With modern part values)
Sander & Janzen (SAJA) - MK5 Taperecorder(s)