Production of power standpoint, SWR meter
Keywords: power standpoint production
Power standby lack is one of the general HAM essential meters, in addition to buying a formal manufacturer, it can be homemade. It is also very good to use DIY's standpoints in the method described below. As for the metering value of the self-made power and stationering, it is just a relative value for amateur fans. It doesn't have to be a week. The power value can read from 1.5, 2, 3 than SWR within the allowable error. During the trial process, the author feels that the production of the standing wave is "It's easy to embroider the flower." Although there are only a few components, I want to adjust the REF's pointer to zero. Not easy. Only by understanding its principles can make the debugging goes smoothly. After you diy in your hand, I believe that you will have a new understanding of the standpoint.
1. The principle of the power standing wave ratio of the magnetic ring mutual hyperplasia (as shown) first analyzes its high frequency circuit. Painting it into an equivalent circuit analysis. The forward voltage is U. The reverse voltage is U. At the two points of A, B, why can independent U-binding and a U back voltage? If the U-I-to-N-N-N-counter voltage cannot be separated separately, it is not possible to perform a positive wave, reverse wave test. First take the U into and the U back voltage on the transmission line L1. When there is a high frequency current in L1, a sensing electromotive force is necessarily generated on the secondary coil L2 of the high frequency transformer T. E = Jωmi This electric potential E forms high frequency current I in high frequency transformers T and R1, R2. The size of the current in the loop, completely depends on the impedance L. R = R1 + R2 and the following relationships are all in each point on the transmission line L1: u = u = u-+ u-counter I = I into -i -i -Inti ---- (1) The impedance of each point on the transmission line is the same. Be
Be
Be
Be
Be
Therefore, the current in the network is on the voltage of the resistance R1 = R2; the capacitor C1 is constituted into a voltage divider, k is a partial pressure ratio. The voltage out of C2 is U3. U3 = ku = k (u) ----- (4) Due to the voltage ratio of C3 and C4 equal to the voltage ratio of C1 and C2: U4 = k (U) Explant: U3 = U3 / 2, U4 = U4 / 2. It is now equivalent to the MR / LZC, and the U1 and U3, U2 and U4 are added, and the U1 is 1/2 U1 after the detection wave, the sympathy U2 is 1/1 / 2U2. Then the A-point voltage is: 1 / 2u1 + 1 / 2u3 = 1 / 2U into -1 / 2U anti-+ 1 / 2U into + 1 / 2U anti-= u into the B point voltage: -1 / 2 + + 1/2 4 = -1 / 2U into +1 / 2U anti-+ 1 / 2U into + 1 / 2U anti-= U in FIG. 3 is a schematic of the power standpoint circuit circuit of the magnetic ring mutual inductance method according to the resistance. First, the electromechanical map is analyzed, and its high frequency loop is equivalent to Figure 4. As seen in FIG. 4, R1 = R2 is described in accordance with the formula (3); the resistance R3, R4 constitutes a partial pressure ratio ku3 = ku = k (U into + U reaction) is now a partial pressure ratio K is equal to MR / LZC And add U3 and U1, U2 to the U4 = U1 + U3 = KU into -ku anti-+ ku + ku anti-= 2KU into U5 = U2 + U3 = -ku into + ku anti-+ KU + KU anti-= 2KU reverse through the above proof A , Two points have put U, u reverse separation A point u into, B point u-counter. U, the U reverse each after the detection pole is passed, and it is a DC component. There is only one end with high frequency components, and the low-pass filtering method of the filter circuit is changed to the PC is possible. Be
2: Production Debugging and Installation Process Figure 1, Figure 3 The size of the printed sheets of the two circuits is 70 mm × 40 mm. Use a single-sided panel to manually engage in. Please refer to FIG. 5: L1 in the high-frequency transformer in the figure is a lacquered wire with φ2.2 mm, directly through the magnetic ring, both ends on the M-type socket, please The square hole excavated by the centerline site of the printed plate is that the magnetic line of the magnetic ring is not shielded by the "ground" of the copper foil. The magnetic ring slides in the site of the center line, and there is a function of fine-tuning inductance. Conditioning zero (REF gear) has a function. The magnetic ring matches the two-hole magnetic ring of the antenna of black and white television, which is modified to a monoforpse ring in advance, and then removes the angular corner and then use. The magnetic ring in which the resistance is divided (Fig. 3) can be magnetic around the magnetic ring = 20, φ10. L2 is a uniform 10T in the enamel wire with φ0.15. Capacitor This should use tubular coated high-voltage capacitors, but it is now difficult to find. The 60 volt monolithic capacitor is used herein. High church can be used with color code, and the pole is used in 1N60, and it is paired with a multimeter R * 1K. When the board is engraved, you should pay attention to the symmetry of the line. The fine-tuning resistance for power meter is soldered in the printed sheet in advance, and then secured to the two long screws of the band switch. Potentiometer with 2 watts. The head is 100 microamines. The grounding of the printing plate is made of a bracket with a copper wire of φ1.5 mm. On the screw of the M-shaped socket, the ground wire of the circuit is to be uniformly aggregated, and the welding is welded to the centerline of the printed board. Before debugging, there is a certain understanding of the composition of the circuit. For example, Figure 1 is finally integrated into a bridge circuit, which is measured by the principle of balance, and Fig. 6 is a power schematic.
Three: Adjustment Figure 1 circuit of the standpoint 4: Seeing that the bridge is balanced in the figure, because C1, C2, R are fixed value, only the number of turns of the high-frequency coil L2 can make the bridge balance. Some information emphasizes the adjustment of two partial pressure capacitors to emphasize balance, and practice the fine-tuning voltage capacitors, although there is a function, it is only a trace change, but the adjustment coil can be greatly adjusted. Balance. The material of the magnetic ring is especially important here. The author tried several domestic magnetic rings, although some high-frequency magnetic rings can work in 29.6 megah, but it is not in the standpoint. After balanced to a certain extent, the sharp point is gone, and the number of times repeatedly adding the reduction is also invalid. How can I adjust the current of the REF file to the zero point of the header. (At this point, you can also find a few magnetic rings to try.) Figure 1 The circuit uses a double-hole magnetic ring of a black and white television antenna matching to modify the use of a single hole magnetic ring. First on the magnetic ring with φ0.15 paint wiring wire 50t, the zero point of the REF block is found with the number of times the number of times. Enter the CW signal of 20 watts of 7 to 14 megahazhi, and the output is output to 10 ohms of 50 ohms. For each of the injected signals, the FWD file (positive file) is adjusted to make the header fullness. Then, quickly hit the REF file (reverse file) look at the position of the clip. If the pointer is high, you can remove the L2, 5T to re-enter the CW signal again, and use the RW to adjust the fullness, and then hit the position of the reverse file. At this time, it will be found that the return value is much more than the first time, that is, the value of the hinge needed to the left is large, and the position of the zero point is small. This is the road to the head, then you can repeat the last adjustment method to adjust. When the table needle points to 5ua, slow down, a circle is removed. In the adjustment, go to the position of the magnetic ring in L1 from time to time, transform its still attitude, which is a factor affecting the zero point location, don't forget that one of the porcelain is fine-tuning, (Small) Another ceramic fine-tuning does not work. After repeated multiple times, the table needle can enter the zero value in the reverse gear. Then it is reversed adjustment. That is, the output terminal is connected to the CW signal, and the positive direction (FWD gear) turns a reverse gear, the original reverse gear (REF file) is turned forward, and the circuit is Symmetrical, this correction method is simple. First mobilize the fullness, then hit the reverse file (which is the first adjustment of the forward file) looks at the clock, but also adjusts the original china that does not work in the original adjustment, Let the table need to return to zero. Figure 1 The adjustment ends of the circuit. Figure 3 Circuit adjustment: 1K ohm potentiometer in the circuit, the zero value is large when the reverse gear is zero. The location of the high-frequency transformer is not fixed in advance! L1 and L2 (in the magnetic ring hole) to use high-pressure insulating silk mat to increase the degree of withstand voltage, and secure the magnetic ring after adjusting with bee. On the other hand, after the zero adjustment, it is quickly fixed and cannot be moved again. If the length of the cutting wire lead wire, the re-winding circle is changed, the balance condition is destroyed, the best point is no repetitive . The A point in the figure is to do a forward voltage test, or the reverse voltage test can also be tested. It depends on the wind direction of L2, wants to change the wreath of removal of the magnetic ring, only change the wire, and the welding position of the line is invalid. In contrast, the circuit is adjusted in the circuit. Because it is a large power resistance from the antenna, the possibility of high power, the possibility of breakdown components is relatively small
Four: Drawing the dial scale in the domestic publication, no regulation of the rules, the standing wave ratio is a function of a function, and the indication of the dial is uneven, the scale is non-linear. The scale formula of the stationbox; SWR scale = formula of the header full power flow × SWR-1 / SWR + 1 portrait power: Schedule 2, 3 gives a dial scale drawing of 100 micro-moon tables. When the power scale is portrayed, it is best to refer to a standard table. For example: Enter a standard 10 watts CW power, you can school 10 watts. Enter a standard 40 watts CW power, you can school 100 watts. Enter a standard 100 watt power, you can school 1000 wadroom. However, when corrected this file, some questions should be noted that the false load should be able to withstand the power of 100 watts. When the host is driven to 100 watts CW power, it will lead to other problems, which is considered. Figure 1 is 200 watts of withholding power, and the receiving power of Figure 3 is about 400 watts, but it is not easy to work. The power gauge of domestic finished products has also told the user in the instructions, with a maximum of 400 watts at 1000 watts.
Schedule 2
power
Dial reading (100UA)
10
31.6
20
44.7
30
54.7
40
63
50
70.7
60
77.4
70
83.6
80
89.4
90
94.8
100
100
Schedule 3
Standover
Dial reading (100UA)
1.2
9
1.3
9.1
1.4
16.6
1.5
20
2
33.4
3
50 DIY standpoint not only saves funds, but more importantly, we have exercised our ability to learn knowledge. When you use this homemade instrument to detect the device's working status, the swinging table indicates our DIY's ability, but let us have a pride. The hard work has become a very joy! I wish my friends a success!
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