Homemade venier for the VHF receiver. Verneier radio receiver. Setting-on frequency. What is "Vennier"

To accurately adjust the radio reception on the frequency of the received radio station, a venier is required - a mechanism that converts the rotation of the adjustment knob into a rotation of the setup organ (for example, a kp rotor) to a relatively small angle. To successfully perform its functions, the venier must have a sufficient transfer ratio and practically not to have a backlash. The proposed friction mechanism has a gear ratio of about six and is designed to work with self-made KPU with
Slender dielectric described by the author in Radio, 2016, No. 12, p. 28, 29 (it is necessary only between the casing of the kpe and the chassis of the receiver, put the gasket with a thickness of 6 mm). From materials for its manufacture, you will need a sheet glass fiberstitol thickness 1; 1.2; 1.5, 2 and 6 mm (instead of a stylotetolite thickness of 6 mm, it is possible to use organic glass or polystyrene of the same thickness), 6 mm thick, a strip of transparent organic glass with a thickness of 1.5 ... 3 mm, a segment of a thin-walled brass tube external
It with a diameter of 7 mm (the author used the knee of the telescopic antenna), epoxy glue and standard fastening (screws and nuts M3, several screws-self-tapping screws and screws), and from the tools - hacksaw for metal, files, electric drills, set roller and tap set for cutting Threads M3.

The venier device is shown in Fig. 1. The lead disk consisting of glued two fiberglass disks 27, the same number of piles 28 and gasket 29, glued to the roller 3, on the left (in figure) end of which the knob of the setting 2. The roller rotates in the bearings 4 and 18, Screwd to plates 5 and 20, which, in turn, are fixed on the chassis of the receiver 26. The movement of the roller in the axial direction is hampered by the washers 22 and pressed the pins 21.

Fig. 1. The device of the friction venier: 1 - the front wall of the receiver case, fiberboard, fix the 3x20 screws to the bar 11, and the chassis 26 - screws 23 with nuts 25; 2 - knob settings; 3 - Roller of the drive disc, brass tube (telescopic antenna knee); 4 - Bearing 1, fiberglass with a thickness of 1.5 mm, mount to children. 5 screws 19; 5 - the plate is large, dvp, fixing the chassis 26 with the help of the corners 24 and screws 23 with nuts 25, and to Bruck 11 - screws 3x20; 6 - screw M3x15, 4 pcs.; 7 - Arrow holder 10, fiberglass (organic glass, polystyrene) 6 mm thick; 8 - driven disk roller, brass tube with an outer diameter of 7 mm (telescopic antenna knee); 9 - screw M3x6, 8 pcs.; 10 - arrow, glass organic thickness 1.5 ... 2 mm, mount to children. 7 screws 9; 11 - Bar 20x20 mm, wood; 12 - drive slave, fiberglass thickness 1 ... 5 mm thick, fix to the holder 13 screws 9; 13 - Holder of the slave disk, fiberglass (organic glass, polystyrene) 6 mm thick; 14 - clips of the coupling of rotation of rotation from the venier to the rotor of the KPU, the fiberglass (organic glass, polystyrene) 6 mm thick; 15 - Rotor roller kpe; 16, 17 - details of the coupling, brass, bronze with a thickness of 0.5 mm, fix to parts 14 screws 9; 18 - Bearing 2 (differs from the bearing 1 with the diameter of the holes under the fastening screws, is indicated in the drawing in brackets), the glass is a thickness of 1 ... 5 mm, mounting to children. 20 screws 19; 19 - screw self-drawing M3x8, 8 pcs.; 20 is a small plate (its outline and holes for the mounting screws to the corners are shown on the drawing of the plate 5 with stroke lines), DVP, mount to the chassis 26 with the help of the corners 24 and screws 23 with nuts 25; 21 - Steel pin, 2 pcs., Press in the children. 3 with final venier assembly; 22 - Steel washer with an inner diameter of 7 mm, 2 pcs., Wear on the children. 3 before pressing the pin 21; 23 - Screw M3x12, 8 pcs.; 24 - Corner Furniture, 4 pcs., Bashed to plates 5, 20 and chassis 26 screws 23 with nuts 25; 25 - nut M3, 10 pcs.; 26 - the chassis of the receiver, roll to the wall 1 screws 23 with nuts 25; 27 - the cheek of the drive disc, the glassstolite with a thickness of 1.5 mm, 2 pcs., Glue to children. 38 epoxy glue; 28 - washer, fiberglass 2 mm thick, 2 pcs., Glue to children. 3 and 27 epoxy glue; 29 - gasket, fiberglass with a thickness of 1.2 mm, glue to children. 3 and 27 epoxy glue.

When you rotate the knob of setting 2, the torque due to friction is transmitted from the drive disk to the slave 12, fixed with the holder 13 and screws 9 on the roller 8. The disc 12 is made of a fiberglass with a thickness of 1.5 mm. The large cutout area under the lead disk makes it flexible, which compensates for the possible inconsistency of the rollers 3 and 8 and the non-plane of the discs 27 and 12. At one end of the roller 8, the transparent arrow of the scale 10 is fixed with the holder 7 (it is observed through the window in the front wall. Radio Cases 1), on the other - connecting it with a roller 15 of the rotor of the coupling KPU, consisting of two holders 14 and fixed on them 9 flat springs 16 and 17. This mechanism node is designed to compensate for the inconveniency of roller 8 and rotor kPa.

In the manufacture of venor parts, it is necessary to pay special attention to the drilling of the holes with a diameter of 7 mm in the details 4, 7, 12-14 and 18. First, they are recommended first to drill the drill with a diameter by 2 ... 3 mm smaller than, and only then Drive up to the desired diameter well sharpened drill. And secondly, try to provide perpendicular to the axes of these holes of the plane of these parts. It is best to use ready-made or produce a special drill holder, providing perpendicular to the drill axis to the plane of the parts being processed. All holes in paired parts (bearings 4 and 18, plates 5 and 20) are recommended to drill together by connecting them when processing into one common package. Approximately 3 mm in the details 7, 13 and 14 are made in detail 7, 13 and 14.

The mechanism is assembled from the host node. Its parts 27-29 glue one on the other and with a roller with 3 epoxy glue. Since the friction venneer needed to work between the discs 12 and 27 occurs due to the deformation of the last, the thickness of the gasket washer 29 should be chosen so that after gluing the clearance between the disks 27 was 0.2 ... 0.3 mm less than the actual disk thickness 12 .

Next, be screwed to the plates 5 and 20 bearings 4, 18 and corners 24, and the holder 13 holder (for fastening the first, screw screws 19, the second - screws 23 with nuts 25, the third - screws 9). After that, the roller 3 with a drive disk through a semicircular cutout in the drive disk, then through the bottom (in the figure) of the holes of the bearings 4 and 18 and install the host node on the chassis 26 with such a calculation so that the plates 5 and 20 are at a distance of approximately 25 mm One of the other. Slightly released the screws of the bearing 18 and changing its position in the small limits relative to the plate 20 (the diameter of the holes under the screws 19 fully allow it to do), are achieved with the minimum friction of the roller rotation 3, after which the metal washers operate on its protruding bearing And it fixes its position in the axial direction by pins 21. The axial backlash, if necessary, is chosen by the selection of the thickness of the washers.

Next to the gap between the discs 27 below, the edge of the disc cape 12 is pasted through the free (top figure) of the bearing holes and the holder hole 13 is drawn 8. Climbing it in the holder 13 screw 6, fix on the end of the roller 3 handle 2 and check the mechanism in operation - When it is normal, it is almost impossible to keep the roller with 8 fingers when rotating the handle 2 is almost impossible.

We complete the assembly of the installation on the roller 8 of the holder 7 with the screw 10 pre-fixed screws 9 and the spring of the spring 17. The second part of the coupling is the holder 14 with the spring 16 - installed on the roller 15 rotor KPU, then check the work of the Vernier as a whole.

The front wall 1 is fixed to the chassis wall 26 screws with nuts, and to the plate 5 - screws screwed into the bar 11.

Fig. 2. View of the docking unit of one of the variants of the practical venier design with KP

Materials of parts and some technological instructions for the type assembly are configured in the signature under Fig. 1. The view of the docking unit of one of the variants of the practical design of the venier with the kpe is shown in Fig. 2.

Under the venier device means a mechanical drive from the adjustment knob to the device for setting the radio reception, allowing the radio listener to tune in to a broadcasting station. The venier device is the main operational control body of the radio receiver, so it should be securely in operation under any operating conditions. There are various designs of venier devices: gear, worm, friction, transmissions with flexible thread, etc.

The constructive difference is consigned in various mechanical complexity and the accuracy of manufacture, and therefore cost. The simplest

and the cheap design of the venier device is the mechanism of deceleration with flexible thread, which has been widely used in broadcast receivers. The mechanical drive from the adjustment knob to the condenser of the variable container (KPE) and the VHF unit is carried out in these cases using a flexible cable. True, when the venier device has a large gear ratio, which is constructively cannot be transmitted with a flexible thread, the gear transmission is additionally entered, usually installed on the KPU block. It should be noted that the venier device with a deceleration mechanism with a flexible thread is less accurate than other applicable transmissions. This is explained by the fact that flexible connection does not have sufficient rigidity, so "dead strokes" and stretching flexible threads can appear during operation, which have to compensate for by introducing additional mechanical devices. However, despite the fact that the transmissions with flexible thread have significant drawbacks, they are the main system of the venier device of broadcast receivers used, mainly for economic considerations. On the other hand, the choice of this transmission system is justified by purely constructive considerations and less high demands on the accuracy of the counting (scale) devices of broadcast receivers.

The constructive advantage of the venier device with a flexible thread is that this mechanical system allows you to place the scale of the radio receiver in almost any spatial position. Scale in this transmission system without structural difficulties can be performed by large sizes, for example, can occupy most of the front surface of the infidel case. This circumstance is essential for broadcasting receivers, since on large scales it is technologically easier to apply indicator divisions, inscriptions and digital designations. At the same time, the scale becomes more visual and convenient for reading it by the radio listener. Accuracy

application of indicator divisions on the scale broadcast receivers is ± 0.2 mm, which is significantly lower than in the special preparation. For example, the accuracy of the location of the strokes on the scale of the Special preparation radio range reaches 0.005 mm. In turn, the relatively low accuracy of the scale simplifies the technology of its manufacture and, therefore, reduces the cost.

Consider what ways the requirements for veneer devices are being implemented in transmission systems with flexible bonding. The basic requirements for veneer devices are the smoothness of the settings and the functionlessness of the transmission.

Under the smoothness of the setting it is understood to move the adjustment knob (in millimeters or angular degrees) to change the setting frequency by 1 kHz.

In broadcast receivers, a permissible error when setting is taken equal to ± 1 kHz.

Thus, on a given smoothness, the setting is calculated by the timing transmission of the radio.

The transfer number of the venier device is determined depending on the class of the radio receiver. In GOST 5651-64, "broadcast receivers" are indicated frequencies and wavelengths that are used in broadcast receivers (Table 2).

table 2

Name range	Frequency, kgz	Wavelength, M.
Long waves	150-408	2000-735,3
Middle	525-1 605	571,4-186,9
Short	3590-12 100	75,9-24,8

However, the above ranges are applied in all classes of broadcast receivers. For example, in broadcast receivers III and IV classes in order to reduce their design, the shortwave range is not recommended.

Calculation of the transfer number of the venier device is carried out in the following sequence.

Knowing that the angle of rotation of the capacitor of the capacitance variable (KPE) is 180 °, the angle of rotation is determined, in which the setting error will not exceed ± 1 kHz or the absolute error will be no more than 2 kHz. Then for long waves, the absolute error of 2 kHz will be V129 part of the range 408 - 150 \u003d 258 kHz; For medium waves - V540 part of the range of 1080 kHz and for short waves V4075 part of the range of 8.15 MHz.

Consequently, the angle of rotation of the condenser variable capacity (KPE) with an absolute error of 2 kHz will be: for long waves 180 ° / 129 \u003d\u003d \u003d 1.4 °, the average waves 1807540 \u003d 0.33 ° and short waves 18074075 \u003d 0.043 °.

Considering that the average qualification setup is capable of installing an angle of rotation with an accuracy of 1-1.5 °, it is obvious that in the ranges of medium and short waves without entering a slowing veneer transmission, it is not possible to adjust the radio with a given accuracy.

It is quite natural that the configuration of broadcast receivers, calculated on the mass consumer, is made by any radio listener, regardless of its specialty and qualifications. For these reasons, a large angular error is allowed on the knob, the value of which can be in the range from 2.5 to 3.5 °.

From the ratio of the angular error on the handle of the setting to the allowed angular error on the capacitor of the variable container, the transmission number of the veneer transmission is determined. Thus, for the average waves, the gear ratio of the venier mechanism, to ensure the accuracy of the setting ± 1 kHz, should be in the range of 7.6-10.6, and for short waves 58-81.5.

Choosing large gear ratios is permissible, however, the number of speed knobs for overlapping the entire range is undesirable to increase more than 15, since in this case the setting time is extended to the broadcast radio station, which causes operational inconvenience. Usually, small gear ratios are used in radio receivers III and IV classes, and large - in the highest

class. Select the transfer numbers less than 7.6-10.6 is not recommended, since the mechanical transmission coefficient is reduced, and the setting of the receiver ranges becomes inaccurate and coarse.

From the above calculations, you can imagine the design of the venier mechanism. For example, for radio receivers III and IV classes that do not have a shortwill range and a gear ratio does not exceed 10.6, it is advisable to install the drum directly on the axis of the condenser of the container. For the highest radio receivers, I and II classes, it is necessary to introduce additional slowing transmission between the drum and the condenser of the variable container.

Finally, the transfer number of the venier mechanism is determined by constructive considerations.

According to the overall structural layout of the radio, the sizes of the chassis, the installation of the main blocks, the location of the loudspeaker and the length of the scale are determined. After coordinating the appearance of the radio with designer artists, which usually represent the sketches of the external design of the receiver, the size of the scale is finally determined, and therefore the desired progress of the index arrow.

It may be that according to constructive calculations, you can increase the course of the index arrow, and consequently, the scale of the radio. For example, in radiols I and the highest class, the course of the index arrow reaches 250 mm.

Knowing the point of the index arrow and an angle of rotation of the rotor kpe, you can determine the gear ratio of the venier mechanism. Depending on the class of the projected radio, we specify the appropriate number of rotation of the handle and, according to constructive considerations, the axis diameter.

If the diameter of the drum D1 \u003d L / 3,14 is obtained too large for the designable design, it is reduced to the required dimensions. In this case, the number of drum revolutions is naturally increasing.

Knowing that the rotor rotor of the variable capacitor is 180 °, that is, the rotor turns to 72-turn, the transfer number from the drum to the axis of the rotor will be i \u003d N1 / N2, where N 2 is the number of revolutions of the condenser rotor.

The ratio of the number of teeth gears and wheels is defined as I \u003d Z2 / Z1.

The number of Z1 gears tooth which is installed on the drum, is determined by technological and constructive considerations. Moreover, choose the smallest permissible number of teeth along a certain Z1 and I and the Z2 gear wheel is calculated. The further calculation of the gear is in the usual way according to the formulas caused in many reference books and technical literature.

The second requirement for veneer devices, the transmission of transmission in mechanical systems with a flexible thread is performed using stretch springs, rollers and split gears. The main reason for the appearance of hopes in mechanical transmission is the occurrence of residual deformation of the thread during the operation of the venier device. The ego phenomenon is more affected when applied as a flexible yarrow cord. Therefore, in terms of production conditions, in order to reduce the residual deformation of the caprochy cord, it is specially drawn by a load for some time before installing in the venor. mechanism. Troubleshooting in the prominent transmission in broadcast receivers is carried out by the same devices that are used to create a flexible thread tension. In fig. 27 shows various kinematic diagrams of devices that create thread tension.

The tension system shown in Fig. 27, VG is the most appropriate in terms of ease of design, since the thread tension force is created by one stretch spring.

In fig. 27, G is depicted one of the most common thread tension systems. The stretch spring is installed inside the drive drum. The tension spring force is somewhat larger 2nd, as it should take into account the friction of the thread on the surface of the drum.

Thus, the simplest on the design are the systems shown in Fig. 27, Vig, of which the system is recommended to use, as the drive drum is used in all veneer devices, which in this case is used simultaneously and for fastening the stretch spring.

In some cases, due to the small size of the scale or small diameter of the drive drum, the VIG system may be unsuitable, so when choosing a system or another, it is necessary to be guided by constructive considerations, determining which of the systems to the greatest extent corresponds to the overall design of the venier device. At the same time, it is necessary to take into account the simplicity of the design and, therefore, its value.

In cases where the need to use an additional slow transmission to a condenser unit of a variable container, it is performed using non-flame or "split" gears (Fig. 28). The shift of the slave gear wheels is carried out by a spring, which chooses between the teeth the gap appearing when they are connected from the lead gear. It must be borne in mind that the moment that creates a spring for shift to the gear wheels must be approximately 1.5 times the moment of rotation. The gearbox module in the venier device is used from 0.75 to 1.5, since the gears with these modules without technological difficulties are performed.

by stamping or pressing. These funds are performed by the basic requirements for veneer devices.

Fig. 28. Constructions of split gears.

In the broadcast receivers, two types of venier devices with flexible relationship are used: two- and one-speed system. Depending on the class of the radio, and therefore, from its cost, the veneer transmission system is selected. In the case when the radio receiver must receive radio broadcasts on the path of amplitude modulation and frequency modulation, as a rule, a two-sighted venier transmission is selected. In this case, a separate setting of amplitude modulation path and frequency modulation path is carried out. A single-proof system of the venier transmission is mainly used in cheap radiation IV radio receivers, in which the range of received frequencies is limited by the amplitude modulation path.

Fig. 29. Kinematic diagram of a two-terrosic veneer transmission.
1 - drum block K.Pa; 2-line AM tract; 3 - index arrow; 4 - stretch spring; 5 - lap gears; 6 - block kp; 7 - guide roller; 8 - drum block VHF; 9 - cable tract FM; 10 - tensioning roller; 11 - AM tract setting axis; 12 is the axis of the CM path setting.
In fig. 29 shows the kinematic diagram of the two-volume veneer transmission.

As can be seen from fig. 29, a two-stroke venier device consists of two flexible communications transmissions, one of which is intended for adjusting the amplitude modulation path, and the second one on the frequency modulation path. In this case, the transmission through the amplitude modulation path has a slow down gear transmission from the drum to the KPU block to increase the gear ratio. Cable tension is created
Spiral spring installed on the drum. In the vertex transmission to the VHE unit, the cable tension is created by a tensioner roller. On the depicted kinematic scheme, the adjustment of the amplitude modulation and frequency modulation path is made from two separate handles.

There are also other designs when, instead of two knobs, one applies one, and the switching to the AM and FM traps is carried out using the couplings depicted in Fig. 30. The designs of these couplings are widely used in the company's broadcast receivers of Philips. In this case, according to the paths AM and the Switching, the switching is carried out by moving the coupling using the rocker to the right and left sleeve. Both bushings are freely sitting on the settings axis and enter into hard engagement with the axis when pressed the coupling to the rubber washer. The movement of the coupling is made from the rocker, which, in turn, rotates from the levers of the main range switch. For a reliable engagement of the sleeve with a movable clutch on its surfaces, spikes are installed, which, when pressed the coupling to the sleeve, are crashed into a rubber washer. Trimming venier gears are mounted on the excavations of the sleeves. In the area of \u200b\u200bthe coupling, the setting axis is plane.

Fig. 30. Phillips connecting coupling.
1 is the setting axis; 2 - sleeve; 3 - rubber washer; 4 - mobile coupling; 5 - rocker.

In fig. 31 depicts the second type of connecting couplings. Switching cable systems to a particular path of the radio in this design is carried out by mechanically fixing the bushings with the setup axis. Both sleeves 2 are freely sitting on the axis, and their movement along the axis is limited to stubborn washers 4. Limiter 5,

made in the form of a plank with a hole under the heel 7, is rigidly fixed on the axis. Planck 6 sits freely on the axis 1, but is rigidly connected with the stud 8, which, in turn, is inserted into the rod 9.

The movement of the rod 9 is carried out from the levers of the basic range of ranges. When the rod 9 moves, the bar is moving to the left, the pin is moving into engagement with the washer 3, pressed on the left sleeve. The washer 3 has several cuts for engagement with the pin 7. When turning the axis, the pin 7 always falls into the necks of the washers 3, since the point

friction of the pin on the surface of the washer is significantly less than the moment of rotation of the setting axis. With the free position of the rod 9 in the mechanical engagement with the axis included the right sleeve.

In fig. 32 shows a single-proof veneer transmission system. This transmission system is very simple and is used mainly for radio receivers IV, which does not have a short wave range and VHF range. Consequently, this vernier transmission has a small gear ratio and does not require the introduction of an additional deceleration to the KPU block. The drum on which the cables are attached is installed directly on the axis of the KPU block. Sometimes a single-proof transmission in order to simplify the kinematic system of the venier device is used in the Radio III Radios, for which, according to GOST 5651-64, is a mandatory VHF range.

Fig. 31. Filips connecting coupling.
1 is the setting axis; 2-sleeve; 3 - curly washer; 4-stubborn washer; 5-limit;
6-mobile washer; 7- pin; 8 - hairpin; 9 - rod; 10-spring.

Fig. 32. The kinematic scheme of one-e-veneer transmission.
1 - drum block KPE; 2nd rope;
3 index arrow; 4-tension spring; 5-drum unit VHF; b - the setting axis; 7 - guide roller.

The main disadvantage of a single-horror system in the case of its use in radio receivers having a VHF block is that when setting up the path AM is inevitably driven by the inductor unit of the VHF block, and vice versa, when setting up the FM tract, it receives a rotational movement of the KPE unit, since These blocks are mutually mechanically connected. Naturally, in this system, the moving elements of the settings blocks are larger than in the two-section system, and, therefore, the reliability of the entire venier device decreases. From the above example, it is clear that not in all cases it is advisable to simplify the design in order to obtain an economic gain, since this issue cannot be solved in the separation from other requirements for a broadcast receiver, for example, reliability.

The direction of movement of the cables in the venier device is determined by the guide rollers installed on the Sofit of the radio chassis or on special brackets. Although the cost of the guide rollers is a minor part of the total value of the radio, when designing, attention should be paid to economic issues of their manufacturing technology. Rollers themselves are usually made from plastic masses.

In fig. 33, and the simplest method of manufacturing and fixing the roller axis is depicted; The axis itself is manufactured by non-center grinding and is pressed into the extrusion performed in the sheet material. In fig. 23, B axis is made with sharpening and fastened by flavored. In fig. 23, B depicted fastening the axis of the roller, made by mechanical metal compression, but the axis itself is less technological in the manufacture than previous designs.

In fig. 34 shows three ways to fasten the guide rollers on the axes: with the help of a stubborn washer selected depending on the diameter of the normal axis but. 894. 007 (Fig. 34, a); Using a spring washer (Fig. 34, b), which does not require the manufacture of grooves on the axis (this method is convenient for axes manufactured by power grinding); Using a hollow rivet, mechanically crimped on the axis of the roller (Fig. 34, B).

Indicative arrows of the radio receiver are usually attached directly on the veneer transmission cable. In fig. 35 A, B, in various designs of the index arrows and their attachment methods.

When designing a venier device, first of all, the reductional system is calculated

transmission. Depending on the class of the radio receiver, the desired gear ratio of the venier device is determined. The following is a preliminary layout, according to which the structural elements are specified, the course of the index arrow, the length of the scale, the design of the tensioning rollers system, etc. The flexible communication performed by the cable transmission should not have sharp beggars, since in this case the movement of the cable is difficult, What leads to its premature wear.

Fig. 35. Constructions of the index arrows.

Constructive complication of the veneer transmission by introducing additional elements (for example, connecting couplings) that increase operational amenities is appropriate only in the highest class radio. In radio receivers III and IV classes, one should strive for the maximum simplification of the kinematic scheme of the venier device.

In broadcast receivers, the scale is graded in kiloherts and meters. The determination of the position of the broadcast radio station is made by the magnitude of the wavelength. The magnitude of the wavelength is graded on the scale from left to right, in the direction of increasing.

For capacitive settings, when the indicator arrow is at the beginning of the scale, i.e. indicates the minimum wavelength or maximum frequency, the capacity of the variable capacitor must be minimal. The rotor plates must be removed from the condenser's stator. In blocks of VHF

with inductive tuning, when a tuning rod is made - a non-magnetic material, for example, from brass, the position of the indicator arrow at the beginning of the scale corresponds to a fully entered tuning rod. According to these considerations, the direction of movement of the cable and, therefore, the indicator arrow is determined. In accordance with the requirements of engineering psychology, it is customary to be the most convenient to rotate the knobs of setting towards the motion of the indicator arrow.

In properly designed veneer devices, the torque value on the handle of the radio receiver setting does not exceed 120 g cm.

The axes on which the drive cable is wound is made with a diameter of 3 to 10 mm. Small diameters apply undesirable, since in these cases the friction between the cable and the axis is insufficient, which leads when the radio is working to slip the cable on the axis. The most convenient axis for the operation has 6-10 mm diameters.

According to the famous IVR and R, we find that the cable effort should not exceed 300 g. To ensure reliable mechanical communication of the cable with a leading axis, 1.5-2 turns are sufficient. A large number of turns harmfully affects the operation of the venier device. This is due to the fact that due to the rotation of the axis, both clockwise and counterclockwise, with a large number of turns of the cable, wound on the setting axis, there is an incision of one turn to another and the jamming of the entire transmission system. It is also not recommended to increase the moment of rotation on the adjustment handle, as in this case the tension of the cable increases, and therefore, its operational reliability decreases, the wear of kinematic elements increases

the system of the venier device, the ease of the index arrow deteriorates.

The ease of the index arrow is one of the advantages of the broadcast receiver. In the highest radio receivers, I and II classes, special attention is paid to this issue. To facilitate the movement of the arrow on the axis of the adjustment knob, the handwheel is installed, the mass of which allows the free accelerated adjusting movement of the arrow along the receiver scale from the light rotary movement of the handle. Flippers are usually made of aluminum alloys or stamped from thick sheet steel.

Today, the manufacture of venier details continued. I made a papers with paper while I realized how best to do it.
From pulley you need to make an input and output for the cable. The output will be "distant". Whatever the threads would be intertwined, drilled a hole of 2 mm at an angle of degrees 30 so that it would come out near the distant side. This will be the outlet for the cable. The second outlet of the hole was pulled out the platform to the plex, drilled the hole and cut the thread M3. Screw the screw with a small rack. The end of the cable will be tied here, and the washer will not let him jump off.

In the photo - the "exit" design for the cable.

With the "entrance" more complicated - you need to install the spring, the CTR will choose the "slack" of the cable. But this problem managed to decide. Embedded the groove is slightly wider than the diameter of the spring, as well as the site, in the center of which cut the thread M3 and screwed the screw with a through hole in the Hat.

In the photo - the design "input" for the cable.

The next part is the flywheel knot. He slept with him for a very long time. In stock There was a flywheel from "Latvia", but his design did not fit me. I had to completely remake it. There was also a suitable sliding bearing, but it has a round case with a diameter of 16 mm. It was the main snag with him. How he managed to secure - it can be seen in the photo.

In the photo - details of the flywheel knot and its "assembly drawing".

The assembly is visible on the second photo (bottom up): a lock sleeve, a hatinax washer, a bearing assembly, mounting area, fluoroplastic washer, flywheel.
As a result, it turned out that:

In the photo - the flywheel assembly knot.

After that, it was placed on the folder places of attachment of the nodes, installed them, slept and tried to assemble the mechanism. To do this, I used a simple harsh thread (the cable is a pity!). It turned out such a "mechanism":

In the photo - trial assembly of the venier mechanism.

On the flywheel axes, the cable rotation knot from the VHF block "Latvia" was secured. I had to shorten it, and since it was made from a very fragile silumin, for fixing on the flywheel axis used steel bandage. In the silhumina, only drilled through a hole for a stopper screw of the bandage.

In the photo - the setting axis.

On the photo the fastening of the manufactured nodes on the falsepal.

After fitting and lubrication, the mechanism earned quite well. The axis rotates smoothly, with a pleasant hand for hand. The surrogate arrow moves smoothly, nowhere will not get anything, the thread will not "eat" anywhere and does not score. In general, he was satisfied.

Again, "smart thoughts", which "comes apart" ...

Already when the mechanism worked, it came to me that a rather strong side load will constantly be attached to the axis of the variable resistor. "It came out" because I saw that the pulley was slightly "scored" inward the future scale. Showing it legally with her hand, I saw that the asis of the variable resistor axis is quite large. It's on KPU, with his rolling bearing!
Those. You need to remake this node - set the "Conduct" axis with its bearing, and the axis of the variable resistor somehow flexibly associate with it. Somehow something like that (what was happening at hand).

When reconfiguring Tuner, the magnetol did not even notice how it was removed, but it was also easy to put it - surprisingly, but such a simple action turned out to be pretty well-intricate, although it consisted of separately not difficult. The essence of the venier device is that it should provide a slowdown in the rotation of the configuration mechanism. A mandatory functioning condition is the complete absence of a "idle" and the slip of the cable. There are three types of venier devices:

friction type
with a toothed transmission
drum with cable

With the last type, I was forced to get acquainted closer, at the same time I made this photo of the cheat sheet.

The installation begins with winding on the rotating shaft of at least 4 - 5 turns of the cable, then it is already fitted on the pulleys and attached to the scale pointer.

In the upper groove of the drum first, one side of the cable is started, then the other. The cable must continue to hold in the tension, as well, throughout the operation on its installation.

The cable is fully started in the drum groove throughout the circumference. And finally, the most uncomfortable (well, just magic) "Pass" - the establishment of the cable in the side opening. It turned out only after several attempts, when he guessed the larger and index fingers of one hand to press the cable to the groove on both sides of the Owl, and send it to the second hand.

Place the spring is most convenient than the whole tweezers having a bent of the tip.

Now we send a scale pointer to the extreme right position, stop hard with your fingers moving the cable and move the scale pointer to the right edge and do not bring to the end of millimeters 10-15. Tighten the drum before moving the pointer to the extreme left position, we look at the distance to the end of the scale. It must be identical to the distance from the right side. If not, now it is no longer difficult to guess how these distances do equal.

What is "Vennier"

But that is the particularly noteworthy in this mechanism, this is its name, from the first time it is possible and not to say, as well, and not to collect. And the name is given by the name of the French scientist and the inventor Pierre Belnier who lived in the 17th century and who first made a detailed description of this device. By Babay Iz Barnaula.

On beamless and cancer - fish!

What will be set out below is a classic option for beggages. When there are no full-fledged antennas, nor corporate equipment for the "normalization" of the existing "rods" - and the desire to "celebrate" rushing through the edge - then read. Maybe it will be useful. In the case when everything is good - turn off the computer and successful DX on the air !!!

Use what's on hand and do not look for another!

For homemade "manual" HF tuners often - based on economic considerations - use KPU with an air dielectric - from old broadcast radio receivers. Often without venier and scales, which is not very convenient when subsequent operation. I, too, at once, got the same. And the desire to refine them.

The appearance of the capacitor, assembled and disassembled - in the photo. It was previously extended through one plate and, as a result, has the total capacity of three sections of about 40 - 250 PF. A pair of such capacitors is quite suitable for the manufacture of hand-held tuner.

For the intended modernization of one enthusiasm will be little. Need "semi-finished products". I was looking for them for a long time and found in a box with fragments of old office equipment. I think many have such a box .... :-)

I chose three gears as a result. The number of teeth in gears will determine the final gear ratio - the gearbox is still. In my end it turned out 1: 3, which was quite suitable. Actually, selected from the pile of gears are:

In one gear you need to make a groove for the kp rocker. The groove can be done in the process of final assembly at the place - it will be easier and more accurate. It is clear that the gears were not chosen as they would like, and those that were in stock. In the existing combined gear hole 8 mm. It was possible to use it for its installation corresponding to the diameter of the screw, but it is too much - there is no such thing in the box. I had to find the rack of the desired length and diameter. As a result, everything turned out well.

The assembly process took not a lot of time. Much longer was originally thought of the design and, especially, the initial gears were selected. The photo shows that they are in the remnants of lubricant - I did not touch her. All the same quieter and softer work. And aesthetics - take care of her later ...

First, we try on the place the first gear. I have the diameters of the shaft and the holes inside the gear and the same. Trusted - coincided well. Let's go further.

Next you need to fix the combined gear. Since the casing of the capacitor is cast, from the aluminum alloy, then nothing is needed - placing and drill in the right place the hole with a diameter of 2.5 mm and cut the thread M3. Everything is clear in the photo.

Well, finally. The groove under the rocker should be done at the place, it is desirable that they combine with a little friction, then you will not need to do damper. As the plastic gear - the groove is not a problem. Shilo, feet and glasses - maximum what you need.

Here, actually, everything.

The attentive reader noted that the "main" gears are not fixed on the cope body and can easily be removed. You can come up with an attachment option, but, first of all, it will somewhat complicate the design, and secondly there is simply no need for it! Since it is not just a kp "by itself", but the element of the construction of the tuner, then there, inside this tuner and there will be a limiter for the axis of the tuning flywheel. This limiter will be the inner surface of the front panel of the case. Only it is enough to choose "at the place" the length of the sleeve, put on the flywheel axis so that it is limited to the front panel, and on the other, he rested himself into the gear with a clock-based configuration. Perhaps in some cases instead of the bush, it will be quite thin washer. It is impossible to limit the flight of design thought.

A thin disk from any elastic material is used as a scale based on the constructor's capabilities. Its diameter is determined only by the dimensions of the body of the entire structure. The disk is toughly attached to the gear number 3.

In the result of the work done, we received not only a venier with a scale, but also combined the axis of the flywheel settings and scales. The use of plastic gears is more advantageous than drawback. It's not a helicopter, it will not rotate anything quickly, but now it is very easy to carry out isolation of the whole kp from the chassis that is necessary for tuner T type.

Several days have passed ...

Looking at the same time lying on the table, the resulting product did not leave me feeling that something was missing. Or vice versa: something superfluous is present ... Creative dissatisfaction. And finally I understood. The design was disassembled, with the help of a winding canvase from the cast case, everything is unnecessary and the missing thing is added to it. Now the design looks like this.

Sections have become not three and four. The stator sections were soldered to the inside of the case. Rotary was attached using a powerful soldering iron at the place and also additionally connected by soldering. Everything is perfectly posted. Code of rotor will be made in any place convenient for mounting the place by a piece of flexible "stocking" soldered in the rear rotor - there is for what to fix it.

That's all. Can be used.

Igor Mishin
UT3im