Construction of the building

To make the body, several planks were cut from a sheet of treated fiberboard 3mm thick with the following dimensions:
— front panel measuring 210mm by 160mm;
- two side walls measuring 154mm by 130mm;
— upper and lower walls measuring 210mm by 130mm;

— rear wall measuring 214mm by 154mm;
— boards for attaching the receiver scale measuring 200mm by 150mm and 200mm by 100mm.

The box is glued together using wooden blocks using PVA glue. After the glue has completely dried, the edges and corners of the box are sanded to a semicircular state. Irregularities and flaws are puttied. The walls of the box are sanded and the edges and corners are sanded again. If necessary, we putty again and sand the box until flat surface. We cut out the scale window marked on the front panel with a finishing jigsaw file. Using an electric drill, holes were drilled for the volume control, tuning knob and range switching. We also grind the edges of the resulting hole. Cover the finished box with soil ( automotive soil in aerosol packaging) in several layers with complete drying and leveling out unevenness emery cloth. We also paint the receiver box with automotive enamel. We cut out the glass of the scale window from thin plexiglass and carefully glue it with inside front panel. At the end we try it on back wall and install the necessary connectors on it. We attach plastic legs to the bottom using double tape. Operating experience has shown that for reliability, the legs must either be firmly glued or fastened with screws to the bottom.

Holes for handles

Chassis manufacturing

The photographs show the third chassis option. The plate for fastening the scale is modified to be placed in the internal volume of the box. After completion, the necessary holes for the controls are marked and made on the board. The chassis is assembled using four wooden blocks with a cross-section of 25 mm by 10 mm. The bars secure the back wall of the box and the scale mounting panel. Posting nails and glue are used for fastening. Glued to the bottom bars and walls of the chassis horizontal panel chassis with pre-made cutouts to accommodate a variable capacitor, volume control and holes for installing an output transformer.

Electrical circuit of the radio receiver

prototyping did not work for me. During the debugging process, I abandoned the reflex circuit. With one HF transistor and a ULF circuit repeated as in the original, the receiver started working 10 km from the transmitting center. Experiments with powering the receiver with a low voltage, like an earth battery (0.5 Volts), showed that the amplifiers are insufficiently powerful for loudspeaker reception. It was decided to increase the voltage to 0.8-2.0 Volts. The result was positive. This receiver circuit was soldered and, in a two-band version, installed at a dacha 150 km from the transmitting center. With a connected external stationary antenna 12 meters long, the receiver installed on the veranda completely sounded the room. But when the air temperature dropped with the onset of autumn and frost, the receiver went into self-excitation mode, which forced the device to be adjusted depending on the air temperature in the room. I had to study the theory and make changes to the scheme. Now the receiver worked stably down to a temperature of -15C. The price for stable operation is a reduction in efficiency by almost half, due to an increase in the quiescent currents of transistors. Due to the lack of constant broadcasting, I abandoned the DV band. This single-band version of the circuit is shown in the photograph.

Radio installation

The homemade receiver circuit board is made to match the original circuit and has already been modified in field conditions to prevent self-excitation. The board is installed on the chassis using hot melt adhesive. To shield the L3 inductor, an aluminum shield connected to a common wire is used. The magnetic antenna in the first versions of the chassis was installed in the upper part of the receiver. But periodically metal objects were placed on the receiver and Cell Phones, which disrupted the operation of the device, so I placed the magnetic antenna in the basement of the chassis, simply gluing it to the panel. The KPI with an air dielectric is installed using screws on the scale panel, and the volume control is also fixed there. The output transformer is used ready-made from a tube tape recorder; I assume that any transformer from a Chinese power supply will be suitable for replacement. There is no power switch on the receiver. Volume control is required. At night and with “fresh batteries,” the receiver begins to sound loud, but due to the primitive design of the ULF, distortion begins during playback, which is eliminated by lowering the volume. The receiver scale was made spontaneously. The appearance of the scale was compiled using the VISIO program, followed by converting the image into a negative form. The finished scale was printed on thick paper laser printer. The scale must be printed on thick paper when there is a difference in temperature and humidity office paper will go in waves and will not restore its previous appearance. The scale is completely glued to the panel. Copper winding wire is used as an arrow. In my version, this is a beautiful winding wire from a burnt-out Chinese transformer. The arrow is fixed on the axis with glue. The tuning knobs are made from soda caps. The handle of the required diameter is simply glued to the lid using hot glue.

Board with elements

Receiver assembly

Radio power supply

As mentioned above, the “earthen” power option did not work. As alternative sources It was decided to use dead “A” and “AA” format batteries. The household constantly accumulates dead batteries from flashlights and various gadgets. Dead batteries with a voltage below one volt became power sources. The first version of the receiver worked for 8 months on one “A” format battery from September to May. A container is specially glued to the back wall for power supply from AA batteries. Low current consumption requires the receiver to be powered from solar panels garden lanterns, but for now this issue is irrelevant due to the abundance of “AA” format power supplies. The organization of power supply with waste batteries led to the name “Recycler-1”.

Loudspeaker of a homemade radio receiver

I do not advocate using the loudspeaker shown in the photo. But it is this box from the distant 70s that gives maximum volume from weak signals. Of course, other speakers will do, but the rule here is that the bigger the better.

Bottom line

I would like to say that the assembled receiver, having low sensitivity, is not affected by radio interference from TVs and switching power supplies, and the quality of sound reproduction differs from industrial AM receivers cleanliness and saturation. During any power failures, the receiver remains the only source for listening to programs. Of course, the receiver circuit is primitive, there are circuits of better devices with economical power supply, but this homemade receiver works and copes with its “responsibilities”. Spent batteries are properly burned out. The receiver scale is made with humor and gags - for some reason no one notices this!

Final video

Construction of the building

— rear wall measuring 214mm by 154mm;
— boards for attaching the receiver scale measuring 200mm by 150mm and 200mm by 100mm.

The box is glued together using wooden blocks using PVA glue. After the glue has completely dried, the edges and corners of the box are sanded to a semicircular state. Irregularities and flaws are puttied. The walls of the box are sanded and the edges and corners are sanded again. If necessary, putty again and sand the box until a smooth surface is obtained. We cut out the scale window marked on the front panel with a finishing jigsaw file. Using an electric drill, holes were drilled for the volume control, tuning knob and range switching. We also grind the edges of the resulting hole. We cover the finished box with primer (automotive primer in aerosol packaging) in several layers until completely dry and smooth out the unevenness with emery cloth. We also paint the receiver box with automotive enamel. We cut out the scale window glass from thin plexiglass and carefully glue it to the inside of the front panel. Finally, we try on the back wall and install the necessary connectors on it. We attach plastic legs to the bottom using double tape. Operating experience has shown that for reliability, the legs must either be firmly glued or fastened with screws to the bottom.

Holes for handles

Chassis manufacturing

The photographs show the third chassis option. The plate for fastening the scale is modified to be placed in the internal volume of the box. After completion, the necessary holes for the controls are marked and made on the board. The chassis is assembled using four wooden blocks with a cross-section of 25 mm by 10 mm. The bars secure the back wall of the box and the scale mounting panel. Posting nails and glue are used for fastening. A horizontal chassis panel with pre-made cutouts for placing a variable capacitor, volume control and holes for installing an output transformer is glued to the lower bars and walls of the chassis.

Electrical circuit of the radio receiver

Radio installation

The homemade receiver circuit board is made to match the original circuit and has already been modified in the field to prevent self-excitation. The board is installed on the chassis using hot melt adhesive. To shield the L3 inductor, an aluminum shield connected to a common wire is used. The magnetic antenna in the first versions of the chassis was installed in the upper part of the receiver. But periodically, metal objects and cell phones were placed on the receiver, which disrupted the operation of the device, so I placed the magnetic antenna in the basement of the chassis, simply gluing it to the panel. The KPI with an air dielectric is installed using screws on the scale panel, and the volume control is also fixed there. The output transformer is used ready-made from a tube tape recorder; I assume that any transformer from a Chinese power supply will be suitable for replacement. There is no power switch on the receiver. Volume control is required. At night and with “fresh batteries,” the receiver begins to sound loud, but due to the primitive design of the ULF, distortion begins during playback, which is eliminated by lowering the volume. The receiver scale was made spontaneously. The appearance of the scale was compiled using the VISIO program, followed by converting the image into a negative form. The finished scale was printed on thick paper using a laser printer. The scale must be printed on thick paper; if there is a change in temperature and humidity, the office paper will go in waves and will not restore its previous appearance. The scale is completely glued to the panel. Copper winding wire is used as an arrow. In my version, this is a beautiful winding wire from a burnt-out Chinese transformer. The arrow is fixed on the axis with glue. The tuning knobs are made from soda caps. The handle of the required diameter is simply glued to the lid using hot glue.

Board with elements

Receiver assembly

Radio power supply

As mentioned above, the “earthen” power option did not work. It was decided to use dead “A” and “AA” format batteries as alternative sources. The household constantly accumulates dead batteries from flashlights and various gadgets. Dead batteries with a voltage below one volt became power sources. The first version of the receiver worked for 8 months on one “A” format battery from September to May. A container is specially glued to the back wall for power supply from AA batteries. Low current consumption requires powering the receiver from solar panels of garden lights, but for now this issue is irrelevant due to the abundance of “AA” format power supplies. The organization of power supply with waste batteries led to the name “Recycler-1”.

Loudspeaker of a homemade radio receiver

Bottom line

Final video

Finally, the long-awaited moment comes when the created device begins to “breathe”, and the question arises: how to close its “insides” and give the design completeness so that it can be used comfortably. This question is worth specifying and deciding what the case is intended for.

If it is enough for the device to have a beautiful appearance and “fit” into the interior, the body can be made from fiberboard sheets, plywood, plastic, fiberglass. The body parts are connected with screws or glue (using additional “reinforcement”, i.e. slats, corners, gussets, etc.). To give it a “marketable appearance,” the body can be painted or covered with self-adhesive film.

A simple and convenient way to make small cases at home is from sheets of foil fiberglass. First, all components and boards are laid out inside the volume and the dimensions of the case are estimated. Sketches of walls, partitions, board fastening parts, etc. are drawn. Based on the finished sketches, the dimensions are transferred to foil fiberglass, and blanks are cut out. You can make all the holes for the regulators and indicators in advance, since it is much more convenient to work with the plates than with a ready-made box.
The cut parts are adjusted, then, having secured the workpieces at right angles to each other, the joints on the inside are soldered with ordinary solder with a fairly powerful soldering iron. There are only two “subtleties” in this process: do not forget to give allowances for the thickness of the material on the required sides of the workpieces and take into account that the solder contracts in volume when it hardens, and the soldered plates must be firmly fixed while the solder cools so that they do not “sink.”
When the device requires protection from electric fields, the housing is made of conductive materials (aluminum and its alloys, copper, brass, etc.). It is advisable to use steel when shielding is required and magnetic field, and the mass of the device does not matter much. A case made of steel, sufficient to ensure mechanical strength of thickness (usually 0.3 ... 1.0 mm, depending on the size of the device), is especially preferable for transmitting and receiving equipment, since it shields the created device from electromagnetic radiation, interference, interference, etc. .
Thin sheet steel has sufficient mechanical strength, can be bent, stamped, and is quite cheap. True, ordinary steel also has a negative property: susceptibility to corrosion (rust). To prevent corrosion, various coatings are used: oxidation, galvanizing, nickel plating, primer (before painting). In order not to deteriorate the shielding properties of the housing, its priming and painting should be done after complete assembly (or the oxidized strips of panels in contact with each other should be left unpainted (with a detachable housing). Otherwise, when assembling the housing parts “paint on a chamfer", cracks will appear that break the closed shielding circuit To combat this, spring “combs” are used (spring strips of oxidized hard steel, welded or riveted to the panels), which, during assembly, ensure reliable contact of the panels with each other.

The metal case made of two U-shaped parts is deservedly popular.(Fig. 1), bent from plastic sheet metal or alloy.

The dimensions of the parts are chosen so that when they are installed one into the other, a closed case without cracks is obtained. To connect the halves to each other, screws are used, screwed into the threaded holes in the shelves of the base 1 and the corners 2 riveted to it (Fig. 2).

If the material thickness is small (less than half the thread diameter), it is recommended to first drill a hole for the thread with a drill whose diameter is equal to half the thread diameter. Then, by striking a round awl with a hammer, the hole is given a funnel-shaped shape, after which a thread is cut into it.

If the material is sufficiently plastic, you can do without corners 2, replacing them with bent “legs” on the base itself (Fig. 3).

An even more “advanced” version of the rack, shown in Fig. 4.
Such a rack 3 not only fastens the upper panel 1 with the lower 5, but also fixes the chassis 6 in the body, on which the elements of the device being manufactured are placed. Therefore, no additional fasteners are needed, and the panels are not “decorated” with numerous screws. The bottom panel is attached to the stand using screw 2 passing through leg 4.
Thickness required material depends on the size of the case. For a small case (volume up to approximately 5 cubic dm), a sheet with a thickness of 1.5...2 mm is used. A larger body requires, accordingly, a thicker sheet - up to 3...4 mm. This primarily applies to the base (bottom panel), since it bears the main force load.

Manufacturing begins with calculating the dimensions of the workpieces (Fig. 5).

The length of the workpiece is calculated by the formula:

Having determined the length of the first workpiece, it is cut out of the sheet and bent (for steel and brass, the bending radius R is equal to the thickness of the sheet, for aluminum alloys- 2 times more). After this, the resulting dimensions a and c are measured. Taking into account the existing size c, determine the width of the second workpiece (C-2S) and calculate its length using the same formula, substituting:
- instead of a - (a-S);
- instead of R1 - R2;
- instead of S - t.

This technology guarantees precise connection of parts.
After manufacturing both halves of the body, they are adjusted, marked and mounting holes are drilled. In the necessary places, holes and windows are cut for control knobs, connectors, indicators and other elements. The control assembly and final adjustment of the body are carried out.

Sometimes it is difficult to fit all the “stuffing” of the device into the U-shaped half. For example, on the front panel you need to install a large number of display and control organs. It is inconvenient to cut windows for them in a bent part. A combined option will help out here. The body half with the front panel is made from separate sheet blanks. To attach them, you can use special corners shown in Fig. 6.

This part conveniently fastens three walls at once in the corner of the case. The dimensions of the corners depend on the dimensions of the structural elements being fastened.

To make a corner, a strip of mild steel is taken and fold lines are marked on it. The central part of the workpiece is clamped in a vice. With light blows of a hammer, the strip is bent, then turned over so that the bent part lies on lateral surface vice, and the middle part was slightly clamped. In this position, the bend is corrected and the deformation of the strip is eliminated. Now the second side of the part is bent, and, after editing, a ready-made fastening unit is obtained. All that remains is to mark the location and drill the holes in which to cut the threads.

Equipment, especially lamp equipment, requires housing ventilation. It is not at all necessary to drill holes throughout the entire body; it is enough to do them in places where there are powerful lamps (in top cover case), on the rear wall above the chassis, several rows of holes in the central part of the bottom cover of the case and two or three rows of holes on the side walls (in the upper part). There should also be holes around each lamp in the chassis. Above powerful lamps with forced ventilation Windows are usually cut out and a metal mesh is fixed into them.

IN Lately, as a result of rapid obsolescence, cases from computer system units appeared in landfills. These cases can be used to create various amateur radio equipment, especially since the width of the case takes up very little space. But such a vertical layout is not always suitable. Then you can take the casing from the system unit, cut it to the required dimensions and “join” it with a “cut” from a second similar casing (or separate panels - Fig. 7, 8).

With careful manufacturing, the body turns out to be quite good and already painted.

Simple technology for manufacturing housings for amateur radio designs with your own hands

Many, especially novice radio amateurs, are faced with the problem of selecting or manufacturing a housing for their design. They are trying to place the assembled board and other components of the future design in cases from old receivers or toys. In its finished form, this device will not look very aesthetically pleasing, extra holes, visible screw heads, etc. I want to show and tell you with an example how, in just a couple of hours, I make a case for a recently assembled SDR receiver.

Let's get started!

First, we need to make a device for securing the parts of the future body. I already have it ready and I’ve been using it successfully for ten years. This simple device is useful for accurately gluing the side walls of the case and maintaining angles of 90 degrees. To do this, you need to cut out parts 1 and 2 from plywood or chipboard, with a thickness of at least 10 mm, as in photo 1. The dimensions, of course, can be different, depending on what kind of housings for structures you plan to make in the future.

photo 1:

The case will be made of plastic 1.5 mm thick. First, we measure the highest parts of the structure, for me these are bulky capacitors on the board (photo 2). It turned out to be 20 mm, let's add a PCB thickness of 1.5 mm and add about 5 mm for the racks into which the self-tapping screws will be screwed when I mount the board in the case. In total, the height of the side walls is 26.5 mm, I don’t need such precision and I will round this number to 30 mm, a small margin will not hurt. Let us write that the height of the walls is 30 mm.

photo 2:

My sizes printed circuit board 170x90 mm, to this I will add 2 mm on each side and get dimensions 174x94 mm. Let's write that the bottom of the case is 174x94 mm.

Almost everything is calculated and I start cutting out the blanks. When working with plastic, it is convenient to use a mounting knife and a ruler. Literally in 10 minutes I had the back wall and side wall blanks (photo 3).

photo 3:

Next, we clamp the back wall into our previously made “device” and glue the side wall, which in my case has a size of 177x30 mm (photo 4. a). Just like the first wall, we glue the second one, turning the blanks on the other side (photo 4. b). “Superglue” is used to glue the walls of the case (for greater strength, you can then go through the corners glue gun, also all the wires can be collected into a bundle and glued to the walls of the case).

photo 4:

Photo 5 (a) shows the result of my work. When properly glued side walls and the angle of 90 degrees is maintained, you can easily glue in the remaining 2 walls and mounting posts for attaching the board. In my version, one wall is blank, and the second has holes for connecting connectors (photo 5 b).

photo 5:

After gluing the entire body, it should be rounded with a file or sandpaper all corners, this will give the body smooth lines and it will not look like a brick. After everything is ready, the board is installed, and with a few drops of glue we glue the cover of the device (photo 6).

photo 6:

Well, the fully assembled receiver in the case (photo 7) is now installed on the wall, does not interfere or spoil the interior of my workplace.

photo 7:

That's all! I spent a couple of hours on all the plumbing work and my wife’s first question was: “What kind of alarm is this?” (joke!)
Success in creative work!

Hi all! Here is an article about making an unusual table radio their hands.

It's cool when the appearance of an item hides its functionality. In order to use this radio, you will have to turn on “Sherlock Holmes” or “Miss Marpool” :) First of all, those around you see a simple wooden sculpture that does not give any hints about what it is or how it can be used. Everything needs to be found out experimentally.

To turn on/off, adjust the range and change the volume, the radio has two rotating rings lying on top of each other. The round base is a speaker that you need to turn to turn it on. homemade.

Due to the spherical shape and weight distribution, craft sits stably on the table (vanka-stand principle). With the exception of the electronic parts, the ball radio is made entirely of wood. The body is made of layers of wood different breeds(layers have different thicknesses).

Step 1: Construction

After a lot of research, a dozen different sketches and brainstorming, I finally found the “ideal design”. Adjustment will be made using rings rather than potentiometer wheels.

Step 2: Selecting wood

During the manufacture of the case crafts Was used different kinds wood We print out the templates, glue them onto the wood and begin sawing and cutting out the wooden blanks.

Step 3: Assembling the “ball”

Let's sand the cut pieces.

Step 4: Turning the body

Let's install the workpiece in lathe and let's start sanding. However, be very careful. Why? After a second, I was "stunned" by the workpiece being torn into small pieces, but I was lucky and was able to find each piece so that I could glue the body back together. The cause of the rupture is an unstabilized workpiece.

Step 5: Add Electronics

Especially for crafts I purchased a simple radio set that included two potentiometers (one for adjusting the volume and turning the radio on/off, the second for selecting the band).