Radiola melody zil 1959 DIY repair

In detail: radio tape melody zil 1959 DIY repair from a real master for the site my.housecope.com.

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The first thing on my list will be a rather ordinary thing - a tube radio "Latvia". But it is dear to me because it was from her that my fascination with retro equipment began 15 years ago, and it was she who became for me a "learning desk" in terms of repairing equipment.

I got it on the occasion - when my parents bought a summer cottage with a house, the previous owner for some reason did not take it, although before that he tore off and took with him even a leaky carpet from the hallway. At that time, the radio, covered with dust and kitchen grease, was catching the Mayak radio with its last strength. The turntable did not work, the VHF tuning cable was cut off, the "green eye" sat down, and the backlight bulbs had burned out long ago. In fact, it was already more of a piece of furniture than a technical device.

Later I found out that I got the oldest version of the radio, released before simplifying the design and "fighting excesses". In the early 60s, the large "green eye" 6E5C was replaced with a simpler 6E1P and transferred to the scale, and instead of gold paint, they began to use grayish-yellow. And then they released a version of "Latvia-M" with the same filling, but much more boring angular design.

Curiously, in my copy you can still see the names "Stalino" and "Stalingrad" on the scale. In 1961, the name of the leader disappeared from geographical maps and from the scales of radio receivers.

Gradually studying the device of the radio, I repaired something in it every year. First of all, of course, the faulty lamps were replaced. “Latvia” began to play loudly and beautifully, and the reception on all waves improved so much that on a clear evening I caught more than a hundred radio stations from all over the world with a piece of wire.

Next, I restored the VHF cable and replaced the cover stopper, which is not present in the photo above. I didn't even have to look for a donor - it turned out that he just fell inside. It's good that nothing closed.

Most of all I had to tinker with the electric motor of the turntable. It did not burn out, as I thought at first, but simply soured from standing for a long time. I had to disassemble it, grind some details a little and lubricate everything properly.

A couple of years later, it was necessary to replace the block for the power cord, but in general we can say that 99% of the radio is equipped with original parts, including even the native ABC selenium rectifier.

Unlike the Mir radio, to which I have devoted a large cycle of posts, Latvia has not undergone a complete restoration of its appearance. She looks her age and ages naturally.

Sometimes I invite friends over and play them records of the 40s - 50s. This helps keep the turntable mechanism in good working order - it is important that parts do not get stuck. And for the winter I put the rubber roller, which transfers rotation from the motor to the "pancake", in a neutral position so that it does not deform.

And finally - technical characteristics for those interested.

Radiola of the 1st class "Latvia" (RN-59) from 1959 to 1964 was produced at the State Electrotechnical Plant "VEF". The radio receiving path has the ranges DV, SV, two sub-bands HF and VHF. Sensitivity in the ranges DV, SV and KV - 50.100 µV, VHF - 20 µV. Adjacent channel selectivity - 40 dB. IF - 465 KHz and 8.4 MHz. Loudspeakers - two 1GD-1 and two 2GD-8. The rated output power is 1.5 W. The range of reproducible frequencies in terms of sound pressure when receiving in AM is 80.4000 Hz, in FM and during operation of the EPU - 80.10000 Hz. EPU with semi-automatic switching on and automatic switching off has speeds of 33, 45 and 78 rpm. Power consumption during reception - 60 W, during operation of the EPU - 75 W. Dimensions - 530 × 420 × 360 mm, weight - 25 kg.

Is your TV, radio, mobile phone or kettle broken? And you want to create a new topic about this in this forum?

First of all, think about this: imagine that your father / son / brother has an appendicitis pain and you know from the symptoms that it is just appendicitis, but there is no experience of cutting it out, as well as the tool. And you turn on your computer, access the Internet on a medical site with the question: "Help to cut out appendicitis." Do you understand the absurdity of the whole situation? Even if they answer you, it is worth considering factors such as the patient's diabetes, allergies to anesthesia and other medical nuances. I think no one does this in real life and will risk trusting the life of their loved ones with advice from the Internet.

The same is in the repair of radio equipment, although of course these are all the material benefits of modern civilization and in case of unsuccessful repairs, you can always buy a new LCD TV, cell phone, iPAD or computer. And for the repair of such equipment, at least it is necessary to have the appropriate measuring (oscilloscope, multimeter, generator, etc.) and soldering equipment (hairdryer, SMD-hot tweezers, etc.), a schematic diagram, not to mention the necessary knowledge and repair experience.

Let's consider the situation if you are a beginner / advanced radio amateur who solders all sorts of electronic gizmos and has some of the necessary tools. You create an appropriate thread on the repair forum with a short description of “patient symptoms”, ie. for example “Samsung LE40R81B TV does not turn on”. So what? Yes, there can be a lot of reasons for not switching on - from malfunctions in the power system, problems with the processor or flashing firmware in the EEPROM memory.
More advanced users can find the blackened element on the board and attach a photo to the post. However, keep in mind that you replace this radio element with the same one - it is not a fact that your equipment will work. As a rule, something caused the combustion of this element and it could “pull” a couple of other elements along with it, not to mention the fact that it is quite difficult for a non-professional to find a burned-out m / s. Plus, in modern equipment, SMD radio elements are almost universally used, soldering which with an ESPN-40 soldering iron or a Chinese 60-Watt soldering iron you risk overheating the board, peeling tracks, etc. The subsequent restoration of which will be very, very problematic.

The purpose of this post is not any PR of repair shops, but I want to convey to you that sometimes self-repair can be more expensive than taking it to a professional workshop. Although, of course, this is your money and what is better or more risky is up to you.

If you nevertheless decide that you are able to independently repair the radio equipment, then when creating a post, be sure to indicate the full name of the device, modification, year of manufacture, country of origin and other detailed information. If there is a diagram, then attach it to the post or give a link to the source. Write down how long the symptoms have been manifesting, whether there were surges in the supply voltage network, whether there was a repair before that, what was done, what was checked, voltage measurements, oscillograms, etc. From a photo of a motherboard, as a rule, there is little sense, from a photo of a motherboard taken on a mobile phone there is no sense at all. Telepaths live in other forums.
Before creating a post, be sure to use the search on the forum and on the Internet. Read the relevant topics in the subsections, perhaps your problem is typical and has already been discussed. Be sure to read the article Repair strategy

The format of your post should be as follows:

Topics with the title “Help fix the Sony TV” with the content “broken” and a couple of blurred photos of the unscrewed back cover, taken with the 7th iPhone, at night, with a resolution of 8000x6000 pixels are immediately deleted. The more information about the breakdown you put in a post, the more chances you will get a competent answer. Understand that the forum is a system of gratuitous mutual assistance in solving problems and if you are dismissive of writing your post and do not follow the above tips, then the answers to it will be appropriate, if anyone wants to answer at all. Also note that no one should answer instantly or within a day, say, no need to write after 2 hours “That no one can help”, etc. In this case, the topic will be deleted immediately.
You should make every effort to find a breakdown on your own before you get stuck and decide to go to the forum. If you outline the whole process of finding a breakdown in your topic, then the chance of getting help from a highly qualified specialist will be very great.

If you decide to take your broken equipment to the nearest workshop, but do not know where, then perhaps our online cartographic service will help you: workshops on the map (on the left, press all buttons except “Workshops”). You can leave and view user reviews for workshops.

For repairmen and workshops: you can add your services to the map. Find your object on the map from the satellite and click on it with the left mouse button. In the field “Object type:” do not forget to change to “Equipment repair”. Adding is absolutely free! All objects are checked and moderated. A discussion of the service is here.

Today I want to change the subject a little and talk about my other hobby. A couple of years ago, leaving the country house, I noticed something large and beautiful near the dumpster. Turning over the wooden case, I read the word "Peace" on a tarnished metal plate. At that time, I still did not know what kind of thing I got into my hands, but I immediately realized that it was impossible to leave it there. Already at home, having entered the Internet, I found out that I had got the Soviet radio "Mir" M-154R, released in 1956.

It turned out that such a "World" is a welcome exhibit in any collection of an old radio. Alas, the previous owners did not know this. They broke off the top cover of the "Mir", tore out the turntable by the roots, removed almost all the lamps and the back wall somewhere, smashed one of the scales and the tuning indicator, and got dirty and scratched the body.

But I did not despair and decided at all costs to restore the radio. At that time, I had almost no relevant experience, so I had to study collectors' forums for many hours, ask questions to the luminaries there, and sometimes act by trial and error.

I started by cleaning the decorative strip. It turned out that its golden color is not a special coating, but a perennial layer of grease and dirt.

After an hour of washing in a solution of acetic acid, I was able to restore the patch to its original silvery color. I polished the brass base with GOI paste.

The rest of the brass elements were processed in the same way:

On the left, the surface is in its original state, on the right - polished.

Then, with the help of the same acetic acid, I brought the pen to the proper form. They are made from carbolite (the old analogue of plastic), and they can only be washed in an acidic solution, but not in an alkaline one, otherwise they will tarnish. You cannot use regular soap.

After removing the handles (not without the WD-40), I was able to completely disassemble the radio and pull the chassis out of the case.

We had to tinker with the wooden "box": somewhere it cracked, somewhere it was stained with paint, somewhere it lost its veneer.

I glued the waste parts by pressing them with clamps or a load.

While the glue was drying, I was filling the radio.I was lucky with it - it was preserved very well, and after I got hold of all the necessary lamps, the radio began to play with a pleasant, clear sound. I didn't even have to change the electrolytic capacitors - having soldered off one of them, I found out that it had lost no more than 10% of the rated capacity.

The chassis is a little rusty under layers of dirt and dust, but I was able to return it to its presentation with the help of oxalic acid (sold as part of detergents), and in some places I re-painted it with "silver".

Having finished with the chassis, I proceeded to the longest and most difficult part of the restoration - the restoration of the paintwork. I repeat that I have not done anything like this before. In the process of studying the topic, it turned out that the Mir radios were among the last to be covered with shellac, a natural material produced by insects living in tropical countries. Shellac is a substance with a much wider range of applications than the glamorous girls who cover their nails with it might think. The windings of transformers are impregnated with its alcohol solutions, in pyrotechnics it is used as a fuel, before the invention of vinyl, gramophone records were made from it, and it is also edible and even has its own food code - E-904.

But, naturally, I was interested in him not from a gastronomic point of view, but as an unusually beautiful varnish for wood, giving it a special shine and a light golden hue. Before proceeding with the application of varnish, it was necessary to wash off the half-century layers of dirt and repair the defects.

The edges of the case were outlined with black stripes - in order to draw them evenly, I came up with a mask made of regular tape. He came up for these purposes much better than a special paint shop, under which the paint flowed. I used auto refinish enamel in a bottle with a brush.

There are many technologies for applying shellac. The use of almost dry tampons is considered classic, leaving only a hazy mark behind them. With this method, several hundred layers are required! The eastern version of this technology also involves setting fire to the alcohol contained in the varnish. Some restorers claim that shellac can only be applied as a polish, with a special oil. At the same time, to be honest, I hardly believe that during mass production in the USSR, the receiver bodies were varnished for several weeks in 300-600 layers, especially when you consider how inaccurately black stripes were originally drawn on my body.

I have never been able to figure out what technology was used to varnish the Mir hull 60 years ago, and I did not understand which of the modern restorers is right and who is not. Therefore, I decided to find my own way, which would combine, on the one hand, practicality, and on the other, a decent appearance. And after several experiments, I was convinced that a good result is obtained by applying shellac with a thick synthetic brush in 8-10 layers with intermediate drying and sanding each.

The varnish should be applied in long strokes strictly along the grain, from edge to edge. The brush must be wrung out thoroughly before applying, making sure that the fibers do not fluff. The strips of varnish must be done quickly and with a slight overlap - then each subsequent one, without having time to harden, will mix with the previous one, and as a result, you get a flat surface without steps.

Side elements before and after varnishing:

The chamfer at the bottom of the front panel, as well as the back of the case, I tinted with ink (as it was in the original).

Finally, it's time for the final build. By that time, I had got hold of many of the missing parts:

In general, Mir is not the most repairman-friendly device. It is impossible to get close to many of its nodes without disassembling the structure completely, and some parts, once removed, then it is very difficult to put them back.For example, all the elements shown in the next photo must be combined "by weight" and inserted at the same time, and only then they can be fixed.

I did it only once from the fifth. If after that it turned out that I had confused any scales, I would probably have shot myself.

Then the assembly process went more vigorous, and I even made a gif out of it.

The amplifier was developed at the dawn of semiconductor electronics. This is the standard scheme used in almost all radio systems of that time. The power of such an amplifier largely depends on the supply voltage, the range of which is quite wide. To drive the output stage, germanium transistors are used, which have not been produced for a long time. By the way, all transistors (with the exception of the output stage transistors) are germanium.

Despite its simplicity, the amplifier provides reasonably good sound quality and can be configured for classroom use. The transistors of the output stage are installed on a sufficiently large heat sinks, although overheating was not observed during operation. The power of the amplifier can be increased by using more powerful transistors in the output stage. In this case, the supply voltage must also be increased.

The ULF circuit starts working from 3 Volts. The maximum supply voltage level is no more than 30 Volts. The input capacitor can have literally any capacitance. In my case, I used the first capacitor that came to hand. The capacitor voltage is also unimportant. The whole circuit is mounted on a getinax board (my least favorite material).

You can see the fuse on the power line on the board. The capacitors of the Yerevan plant are immediately striking. Probably, the capacitors have long been out of order, or rather, they have lost most of the initial capacitance.

But I decided not to change anything on the board. Then the power amplifier was turned on. I was amazed - the scheme worked! Despite the significantly low power supply, the amplifier played excellently.

Of course, this ULF cannot be compared to the ultra-linear Linsley-Hood scheme, but it plays well for its age.

Melody-104 stereo is a stereophonic block radio, which includes: a radio receiver for long, medium, short and VHF radio waves; turntable with II EPU-62SP (see the description of the player and this EPU at the link); two acoustic systems 6АС-2 (quite original design, with two speakers - LF 10GD-34 and in front of it HF - 3GD-2). The amplifier is located in the radio receiver unit. Serial production of this radio began in 1978 at the Popov Riga Radio Plant - Radiotehnika RRR.

Outwardly, this radio is very difficult to distinguish from Melody 101-stereo, only with a slightly different design of the player and other EPUs in it. and internally the same, because 104-stereo Melodies is the same 101-stereo Melodies, with minor modifications. The 104-stereo melodies were produced in three types, essentially the same: in two, the difference was in completing the turntable with a corundum or diamond needle, and the third used an EPU with a magnetic pickup head GZM-105 (IIEPU-62SM). The further development of this radio was the emergence of the stereophonic radio Melody-105-stereo, which was an improvement in the device under consideration today, including externally.

There are many descriptions and photographs of this radio on the Internet, so I will not repeat myself and will post only those materials that do not exist, I think they will quite logically complement the available information.

U1 - VHF unit. Stands alone, in its standard performance of those years. aluminum screen case, steel bottom. Under it is a board, marking Cr6.672.111. The board has two transistors GT313A, one GT322A, three diodes (varicaps) KVS111B.