The receiver is superheterodine with a double frequency conversion and fixed IF. Such a decision is made due to the problems of manufacturing high-quality quartz filters at one conversion and distribution of amplification by frequencies with double conversion in order to obtain a stable strengthening in general.
Application As a pre-selection filter SIF TV with a bandwidth of 300 kHz provides the input of the K174H2 from powerful non-band interference, and also simplifies the selection of quartz resonators on the 1st PC and HO with a 100 kHz separation. Imported analogue of the FP1P8-62.0 filter (yellow point on the housing) - SFT5.5MA.
The IF value, depending on the filter used, can be 6.5 MHz with an appropriate adjustment of the frequency of GPA and quartz resonators.
Chip K174х2 In addition to high gain at 500 kHz, the built-in cascades of effective ARU.
Highly dynamic, disabled yrts are in demand on RF bands.
The use of a dual balance mixer provides high level suppression of intermodulation interference.
Suppression of the interfering carrier is carried out in parallel to the oscillatory contour of the quartz resonator sequential resonance And the EMF transmittance is touched in the bandwidth using an alternating condenser with a solid dielectric from the pocket receiver, whose sections are topped.
With the sequential turn on multiple resonators, the recording strip decreases. So, with one resonator (in terms of 6/50 dB) - 400/1000 Hz, at two - 200/450 Hz and at three - 70/200 Hz.
the P-i-n diode disables the notch node.
A small commentary about working in the flow of pulse interference (NB).
All modern transceivers have a built-in NB, but use it - units of operators and, mostly, with interference from the ignition of the car, because NB reacts clearly only on them (single), the thunder discharges (smeared) reacts mediocre.
Most importantly, when receiving a powerful station near the frequency (outside the filter bandwidth), a beneficial signal is distorted, because In the SSB voice spectrum, short pulses are present, which the useful signal is "tread" as the keyboard path.
The Karlson-II receiver scheme introduced a time delay for triggering far after the end of the impulse of the interference based on a single-seater assembled on the K561L7 logic.
Thus, interference with a duration of 1 μs up to 2 ms is stacked into the interval of a running single-seater with a delay elements of 2 ms.
When checking the performance of this assembly of the scheme, the receiver did not react at all on the pulses of the gas electric lighter at the antenna itself and away. Also successfully smear pulses from light switches. I think that and with thunderstorm discharges.
It should be noted that the reading of the S-meter in the receiver is not blocked by the enhancement handle on the PC (RF). This is done specifically to set the desired gain and with it to read the reading of the s-meter, and not as in imported devices.
Those. "I hear - I see."
The frequencies of the contour settings on the diagram are highlighted in red.
Active low frequency filter assembled on low noise operating amplifiers Cuts frequencies above 2.4 kHz, thereby suppressing the tired "white" noise and adjusts the ACH EMF to the characteristics of a comfortable ether.
KV-receiver "Karlson 3"
A receiver is a superheterodine with a double frequency conversion.
Scheme features:
Number of ranges - 11;
Thunderstorm indicator (atmospheric statics);
Broadband band input filters;
Ring diode high-level mixer;
Frequency Mesh Synthesizer (PLL);
Three input digital display of the frequency of the input signal C HAC;
System of range electronic (diode) switching;
Radio frequency broadband adjustable amplifiers on two shutter field transistors;
Three strip Filter IF I;
High frequency II II providing selectivity on side channels;
Quartz filter (FOS) based on PAL resonators;
Integral tract of GPD, increasing and detection of II II;
High speed AGR on the inverter;
Switch s-meter;
Combined increasing LB.
A block diagram of a receiver is presented on a sheet # 1.
Schemery of device sheet # 2 and # 3.
Receiver flowchart
The signal from the antenna Fig. (DFT). Depending on the width of the amateur range and the setting frequency apply different types DPF. On a 10-meter range, in all three frequency 500 kiloherts sectors, one common filter of the species of A.
CD409 diodes work as diode keys, well-proven in the selectors of the channels television receivers. In comparison, C. electronic keys On ordinary silicon diodes, there is no reverse locking voltage. Of course, the replacement of KD409 on P -i -N diodes is welcome.
Next, the filtered podia band signal enters the amplifier high frequency (UHF) assembled on two CP327 feld transistor. Its main purpose is a low-noise amplifier with a controlled enhancement from the automatic gain control system (ARU). The diode established in the source creates a fixed displacement on the 1st shutter, thereby ensuring the stable adjustment V.A. Characteristic when controlling the 2nd shutter. The input resistance of such a stage is adjusted for approval from the DPT.
Mixer (cm) ring. Turning on sequentially two diode in each shoulder allows you to averaged V.A. Shoulder characteristics and abandon a balancing resistor that makes loss when converting. For such garlands of diodes, an increased amplitude is required (power) from the generator within 3-4V eff.
To overlap all the ranges, the interpolation method does not require the use of deficient range quartz resonators. This is achieved by using the frequency mesh synthesizer based on phase auto-adjustment (PLL).
The quartz generator (kg) collected on the logic K561L7 and its phase inverters are created at the inlet of the pulse phase detector (FD) the frequency grid (harmonics) with an interval in 500 kHz applied quartz resonator.
At the same time, a high frequency signal is received on the PD input (HF) from the voltage controlled generator (GUN). As a result of the comparison of the period of signaling of the GUN and the harmonica of a quartz generator (kg) at the exit of the FD there is a voltage direct current Various polarity, depending on the gear departure sign. This voltage enters the frequency control matrix of the frequency control matrix, summing up or sulfing with the constant voltage of the DC on a divider from the resistors.
Thus, by connecting the diode switch, the range capacitors parallel to the HUN induor coil, the input of the 500-kilogenesis zone of each range for a fixed frequency with the auto-adjustment is provided according to Table 1.
It is interesting to note that in addition to 11 amateur ranges, the use of a frequency mesh synthesizer with other fixed frequencies allows you to create other sectors of the reception. So, for example, 27 MHz, broadcasting 31 meter, etc.
It is important here that in the frequency mesh interval from 8 to 23 MHz - only one HUN inductor is operating. For other frequencies above or below, it will be necessary to connect other inductors.
To ensure a stable amplitude for ranges at the output of the synthesizer, an automatic level control system (ARU) is used. The principle of its operation is based on the formation of voltage of control on the 2nd gate of KP327, with a fixed voltage with two diodes 1B on the adder and, negative polarity of its proportional RF, the synthesizer output.
From a separate exit, through the source repeatment repeat on KP303, the RF signal also enters the first input of the digital scale meter (CHC). The frequency synthesizer should be shielded, and its power must be entered through passage capacitors.
From the outlet of the ring mixer (cm), the spectrum of the converted signal enters the adjustable, low-noise amplifier of the first (variable) intermediate frequency (UEUs i) compensating for the signal loss in the passive mixer, see Installation after a diode mixer diagrams of the diplexer is not required for the reasons of the low value.
IF I and its wide range of coverage.
EPUs I load is broadband transformer (SPT) and three band-bandless non-rebuilt strip filter with a bandwidth of 500 kHz. The amplitude-frequency characteristic (ACH) of the operation of this filter is shown in Fig.2. The resonant overlap of the bandwidth bands of two (!) Adjacent amplitude characteristics is summed and compensates for the amplitude failures from the separation of frequencies of the consistent resonance circuits. The participation of the third resonance, relatively first, always in antiphase. Thus, the second (medium) circuit with a resonant frequency of 6.25 MHz is the main symmetrical gear ratio in the middle of the bandwidth.
In the PLL phase detector scheme there are errors. Instead of capacity in 33 PF, there should be 0.033 IFC and VD4 and VD7 diodes and VD7 in reverse polarity. The correct scheme is shown below.
Further, the spectrum of the signal of the PC I with a strip of 6.0-6.5 MHz is supplied to the integral chip MC3362 that transformation of this frequency in the II II equal to 8867 kHz Fig.3. This frequency value is dictated by the use of widely available quartz resonators PAL in the design of the main selection filter (FOS). In this case, the frequency of the adjustment of the generator of a smooth range (GPA) must match
2367-2867 kHz., As an arithmetic difference in PC II - PC I. This generation value is sufficiently stable for the temperature and mechanical stability of the GPA.
In the absence of PAL resonators it is possible to use the other 7 pcs. Quartz per frequency in the frequency range of 8.5 ... 9.5 MHz, with appropriate change in the GPD restructuring range.
Rearrangement of the frequency of the GPD - electronic using a multi-turn resistor.
The resonance of the quartz resonator of the supporting heterodyne (og) can be adjusted by the LC elements on the lower SCHA of the Quartz Filter (KF) for the formation of the upper sideband of the reception (USB). Changing the desired reception band by range occurs automatically (synchronously) with selected values \u200b\u200bof the synthesizer grid frequencies.
In order to increase the sensitivity of the PC II path, as well as for the presence of the third adjustable amplifier, a low-noise broadband Cascade of the UPC II on the two-lifted field transistor KP327 was introduced on the two-adjustable cascades, which, at three adjustable cascades, it allows to obtain a gain adjustment depth over 80 dB. With the EPU loading unit II, the amplitude of the II signal II enters the ARU detector. The resistor included in sequentially provides temporary delay in the response from pulse interference. The value of the discharge time of the RC circuit is 1C.
Due to high input resistance field Transistor The first cascade + operational amplifier, as a highly sensitive Millivoltmeter with a DC amplifier (POP), it became possible to use not a polar capacitor with a capacity of 1 μF, which ensures high speed of the ARU ring.
For DC balancing S-meter included in the bridge diagonal. This allowed independently of the current of the regulating bipolar transistor, if there is no useful signal, set the arrow of the indicator to zero.
From the control outputs of the MC3362 chip, the values \u200b\u200bof the GPA and OG frequencies are fed on respectively the second and third digital scales (CHC).
When leaving the GPD generation frequency, the control voltage of the digital auto-liquefaction (HACK) appears at the CHC output (HAC), which enters the built-in versions of the auto-adjustment of the microcircuit, thereby compensating for the care of its frequency. When rotating the electron rearrangement of the TSSH, the CHC does not respond to rapid changes in the measured frequency.
I would like to note the design of the installation on the front panel of the CSS receiver lED matrices Bright emerald glow. Receive the frequency of reception from such a display is not very pleasant for vision. Installation of color protective braids does not allow to get rid of the visible viewing of the case of a group of matrices. If the indicators cover a tightly matte filter of white paper under a transparent plexiglass or the plexiglass itself from the inside to handle fine-grained sandpaper, the view of the glowing (translucent) digits of the display acquires a civilized, fascinating effect! When the scale is disconnected, only a white rectangle will be visible on the receiver panel, and if it is in the white color of the color of the front panel itself - stylish.
KV-receiver Karlson
A receiver diagram is a superheterodine with a double frequency conversion and quartz first heterodyne. Application domestic microcircuits 174-series is substantiated principled due to the availability of their acquisition. Overlapping ranges: 80 , 40 , 20 , 15 and 10 meters. Rod work: loud reception SSB. and CW. radio stations Sensitivity: 0,3mkv. Food: 8-9V. DC, when consuming in silence mode 26mAWhat makes it possible to feed the receiver from the battery type (6F22) "Crown".
The characteristics of the scheme are:
- rEST-up to the entrance selector,
- attenuator attenuating input signal,
- the simplest switching ranges
- using a set of quartz resonators from UW3DI,
- two-level, high-speed ARU system for inverters,
- non-rebuilt strip filter 1st PC,
- the use of EMF as a primary selection filter,
- supplement generator with frequency adjustment element,
- lED S-meter,
- adjusting the amplification of the inverter
- adjusting gain across NC,
- sustainable work of cascades,
- high repeatability design.
The input circuit is rebuilt on the ranges performs the role of the first oscillation of the selection device. This allowed, with the corresponding reinforcement reserve, to abandon the 1st incentive, eliminating the three-kite filter, eliminating the bulky, multisective adjustment kpp. The diagram of the selective input part of the receiver allows work with the coaxial feeder of the antenna.
To reduce the noise level, the K174PS1 microcircuit is powered by a voltage of no more than 8 V. Its load circuit C7 L3 is asymmetrical, because sufficiently available symmetry of the input and quartz heterodyne scheme. Perestroika frequency 1st PC: 6,0 ....6.5 MHz.
The attenuator works on the principle of controlling the magnetic flux in the core. If instead of R1 install an alternating resistor resistance to 1kom, then such a smooth attenuator will ensure maximum damping when short closure Not less than 40 dB.
The second frequency converter with a separate GPA and the ECUs on 500kHz, assembled on the K174Kha2 chip. With a supply voltage, 8V is provided by the minimum of the noise of the OEX and the high steepness of the adjusting characteristic of ARU. The frequency of the IF 500 kHz allows you to fully implement the enhancement of the chip, which is in the diagram with a double frequency conversion in excess.
The system of ARU on the inverter - two-level. One Diode detector ARU VD6 (Germany) is enough to ensure high-speed control of the enhancement of cascades. This was the possible exception of the classical options for all resistors of the detector load, except for the input of the chip (on the output 9). In turn, it made it possible to reduce the capacitor C31 capacitor, which determines the reinforcement time and additionally improve the dynamic characteristics of the ARU in the speed of operation. The chain of successively connected VD7 diodes, VD8 generates a constant time for the release of AGAR due to the voltage averaging on the C31 condenser for the recovery time is always equal 0.7sThat ensures the elimination of the "dropping" effect of the signal from the operation of powerful local transmitters. The R11 resistor creates a displacement voltage on the VD6 detector, providing the ARU response delay to the input signal level S \u003d 3. When the input signal level is reached, S \u003d 9 and above, the step of adjusting the second-level gain is starting. Through a chain of sequentially included diodes VD2, VD3 (silicon and germanium), the voltage is provided by the voltage threshold to start control of the gain of the RF Cascade of the CC174HA2 chip. At the same time, a comfortable reception on the sound level of DX and local operators is the same. Forced, parallel, independent control of the control voltage from the RF gain control, via the VD5 isolation diode changes the amplification of the IF to the operational level and, as a result, a decrease in noise without blocking the s-meter indication.
GPD is made according to the classic scheme. Overlapping in frequency 5,5 ....6.0 MHz implemented variable condenser with air dielectric. To ensure temperature stability, be sure to use as C13, C16, C17 type capacitors Kso. Without special measures, applying the contour coil on the frame of polystyrene and winding the PEV wire, stability was obtained characterized as the departure of the generation frequency in 1 hour per 120 Hz.
Sound FNF consisting of C36, C37, C38 and DR1 at the input of UNG creates a slice sound frequency above 3 kHz.
Low frequency amplifier on the K174UN4 microcircuit provides high-quality gain for working headphones or small-sized dynamics of power up 1 W.. Elements of private correction form a speech frequency spectrum.
Details and design.
RF transformers T1, T2 are wound in three and, respectively, two, wires of the PEV 0.1 brand on ferrite rings of any brand with a diameter of 4-10mm. Number of turns - 10. Winding serials are connected "Start with the end".
Coils L7, L10, are used ready from the PF-465 pocket receiver. They are wound on section frames, placed in ferrite cups and are concluded in metal screens. The number of turns of contour coils is already executed on the frequency of 465kHz. Only the domain of the l8 communication coils L8, L11 wire with PAL or PALSHO to 15 turns and rebuild the circuit with a core to 500kc.
Coils of the strip filter L3, L4, L5, have 18 turns, and L6 - 4 turns wrapped with PELSHO 0.1 and are placed in small carbonyl cups of the Sat type.
The inlet selector coils are wound on the frames with a diameter of 6-8mm, the wire lytioned with windings: L1 - 8 turns, L2 - 10 turns, L3 - 30 turns (in the ball) with a tap of 10 turns from below. The GPD L13 coil has 30 turns wound on the frame with a diameter of 6-8mm, the turn to the turn of the PEV 0.35 wire and placed in the screen.
C1 Caluation Condressor is small-sized from a pocket receiver with a solid dielectric. Capacitor C12 of a small-sized type with rotation bearings and a mechanical venier of any design is preferably with a slowdown of no more than 10 kHz per revolution of the adjustment knob.
As throttle, DR1 FNH is used one of the windings of the transformer LF from the pocket receiver. The K174UN4 microcircuit is equipped with a small cooling radiator.
KD522 diodes can be replaced with any silicon impulse, and D9 on any RF Germany. Instead of VD13, any rectifier diode can be used.
Range switch is a small-sized gallery type. The length of the connecting wires to quartz resonators should be shorter if possible.
When installing, the attenuator should be placed near T1.
Setting.
Contour settings frequencies:
L3, C7 - 6.25 MHz L4, C8 - 6.0 MHz L5, C9 - 6.5 MHz L7, C28 - 500kHz L10, C35 - 5 00CHz
The procedure for setting the radio is as follows:
- connect the frequency meter or control receiver to C22 and the L13 core adjustment to set the frequency of the GPD overlap in the range of 5.5 ... 6.0 MHz. If necessary, for the "stretching" of the tank, set the concessor of a permanent container of the CT gray condenser with a variable condenser.
- connect the RF Voltmeter to L11 and rotating the loop core L10 C35 to achieve its maximum reading;
- connect the GSS to L6 and apply the RF is not a modulated signal with a frequency of 500 kHz,
- variating the amplification regulator Rf, configure the core of the outline L7 C28 to the maximum of the luminescence of the S-meter LED and the sound of the beats in the loudspeaker;
- connect the GSS to the antenna of the receiver's nest, to sue the NF is not a modulated signal with the frequencies of setting up the first IF strip filter, according to the three frequencies of its circuits. Configure them at the maximum luminescence of the s-meter and the volume of the tone of the beats;
- without shutting down the GSS from the antenna, firstly,enable 80. meter range Reception and submit a test signal with a frequency of the middle of this range. Rotating handle condenser SEL.find the resonance of the maximum level of reception. On the limb of the tincture of the input selector to make a mark on a visitor from the plexigla in the form of a zone of reception of the frequencies of this range. If necessary, adjust the core of the contour range coil, the resonance zone can be shifted at a convenient place to read from the limb;
- the remaining areas of the ranges of 40m, 20m, 15m, 10a and 10b are marked on a limb with the correction of cores of the corresponding coils in the same sequence.
It is very convenient to have three sedimentary threads with adjustment zones: on the first closer to the axis of the condenser risks of 80 and 40 meters, on the second (medium) risks of the ranges of 20 and 15 meters, and on the third, with a large radius, the selector setting zone in 10-meter Range.
Excessive reinforcement of the PC 500kHz path can be compensated by the shunt resistor R9 or exclude it from the scheme at all.
Test The receiver was carried out as follows.
1. Indoor on the table were installed: TS-870 transceiver, DE1103 radio and Karlson.. The 1-meter antenna-wire is alternately connected to each of these devices when receiving the same radio station.
Comparative level of receipt of the signal is:
- TS-870 - 8 points - Karlson.- 7 points - degen 1103 - at the level of internal noise.
2. On the table to the same outdoor antenna Connected: TS-870 and Karlson.. Signal level of the received control station and comfort ARU Karlson. Not inferior to the factory apparatus, and with an explicit wins in a soft, analog sound.
3. Work was observed on the ether of the neighbor on the IC-718 and PA transceiver on the GU-74 located 500 meters from the reception site. At the same time, the "zakla" Aru on Karlson. Not noticed, and the presence of a powerful local station is not felt outside the detuning more than 6 kHz.
4. When the antenna is turned off, the maximum gain of the LF and the IF, the level of internal noise of the receiver Karlson. When working on a speaker of 0.5 W 8, does not pay attention.
I will be grateful to see your reviews sent to the address: [Email Protected]
10/16/2008 Supplement to the article "Karlson KV-receiver"
Below are the pictures of the printed circuit board:
- general form;
- kind of details;
- type of conductors from parts;
- view of the conductors from the foil side.
- The Layout file file for upgrades is posted on
- File with drawings printed circuit board Karlson _pcb.zip.
Possible replacement of chips for analogues:
- K174PS1 on SO42P;
- K174х2 on TCA440, A244D;
- K561L7 on K176L7, CD4011;
- K174UN4 - no analogs, but will suit any 9-volt integral LC amplifier, for example LM386N with an appropriate inclusion scheme.
Boris Popov (UN7CI)
Petreopavlovsk, Kazakhstan.
KV-receiver Karlson
Boris Popov (UN7CI)
petropavlovsk, Kazakhstan
A receiver diagram is a superheterodine with a double frequency conversion and quartz first heterodyne. The use of domestic chips of the 174-series is substantiated in principle due to the availability of their acquisition. Ranges of overlapping frequencies: 80, 40, 20, 15 and 10 meters. Roda work: loud-reducing reception SSB and CW radio stations. Sensitivity: 0,3mkv. Meals: 8-9V DC, when consumed in the silence mode 26mA, which makes it possible to feed the receiver from the battery of type (6F22) "Crown".
The characteristics of the scheme are:
rEST-up to the entrance selector,
attenuator attenuating input signal,
the simplest switching ranges
using a set of quartz resonators from UW3DI,
two-level, high-speed ARU system for inverters,
non-rebuilt strip filter 1st PC,
the use of EMF as a primary selection filter,
supplement generator with frequency adjustment element,
lED S-meter,
adjusting the amplification of the inverter
adjusting gain across NC,
sustainable work of cascades,
high repeatability design.
The input circuit is rebuilt on the ranges performs the role of the first oscillation of the selection device. This allowed, with the corresponding reinforcement reserve, to abandon the 1st incentive, eliminating the three-kite filter, eliminating the bulky, multisective adjustment kpp. The diagram of the selective input part of the receiver allows work with the coaxial feeder of the antenna.
To reduce the noise level, the K174PS1 microcircuit is powered by a voltage of no more than 8 V. Its load circuit C7 L3 is asymmetrical, because sufficiently available symmetry of the input and quartz heterodyne scheme. Perestroika frequencies 1st PC: 6.0 ....6.5 MHz.
The attenuator works on the principle of controlling the magnetic flux in the core. If you install instead of R1 variable resistor 1kom resistance, then such a smooth attenuator will provide maximum attenuation with a short circuit at least 40DB.
The second frequency converter with a separate GPA and the ECUs at 500 kHz, assembled on the K174H2 chip. With a supply voltage, 8V is provided by the minimum of the noise of the OEX and the high steepness of the adjusting characteristic of ARU. The frequency of the IF 500 kHz allows you to fully implement the enhancement of the chip, which is in the diagram with a double frequency conversion in excess.
The system of ARU on the inverter - two-level. One Diode detector ARU VD6 (Germany) is enough to ensure high-speed control of the enhancement of cascades. This was the possible exception of the classical options for all resistors of the detector load, except for the input of the chip (on the output 9). In turn, it made it possible to reduce the capacitor C31 capacitor, which determines the reinforcement time and additionally improve the dynamic characteristics of the ARU in the speed of operation. The chain of sequentially connected VD7 diodes, VD8 generates a constant time for the release of ARU due to the averaging voltage on the C31 condenser for the recovery time is always equal to 0.7C, which ensures the exclusion of the effect of the "dropping" signal from the operation of powerful local transmitters. The R11 resistor creates a displacement voltage on the VD6 detector, providing the ARU response delay to the input signal level S \u003d 3. When the input signal level is reached, S \u003d 9 and above, the step of adjusting the second-level gain is starting. Through a chain of sequentially included diodes VD2, VD3 (silicon and germanium), the voltage is provided by the voltage threshold to start control of the gain of the RF Cascade of the CC174HA2 chip. At the same time, a comfortable reception on the sound level of DX and local operators is the same. Forced, parallel, independent control of the control voltage from the RF gain control, via the VD5 isolation diode changes the amplification of the IF to the operational level and, as a result, a decrease in noise without blocking the s-meter indication.
GPD is made according to the classic scheme. The overlap of 5.5 ....6.0 MHz is carried out by an alternating capacitor with an air dielectric. To ensure temperature stability, it is necessary to use as C13, C16, CSR capacitors as C13, C16. Without special measures, applying the contour coil on the frame of polystyrene and winding the PEV wire, stability was obtained characterized as the departure of the generation frequency in 1 hour by 120 Hz.
Sound VHC consisting of C36, C37, C38 and DR1 at the input of UCH creates a slice of sound frequencies above 3 kHz.
The low-frequency amplifier on the K174UN4 microcircuit provides a high-quality gain for working headphones or a small-sized dynamics of up to 1 W. Elements of private correction form a speech frequency spectrum.
Details and design.
RF transformers T1, T2 are wound in three and, respectively, two, wires of the PEV 0.1 brand on ferrite rings of any brand with a diameter of 4-10mm. Number of turns - 10. Winding serials are connected "Start with the end".
Coils L7, L10, are used ready from the PF-465 pocket receiver. They are wound on section frames, placed in ferrite cups and are concluded in metal screens. The number of turns of contour coils is already executed on the frequency of 465kHz. Only the domain of the l8 communication coils L8, L11 wire with PAL or PALSHO to 15 turns and rebuild the circuit with a core to 500kc.
Coils of the strip filter L3, L4, L5, have 18 turns, and L6 - 4 turns wrapped with PELSHO 0.1 and are placed in small carbonyl cups of the Sat type.
The inlet selector coils are wound on the frames with a diameter of 6-8mm, the wire lytioned with windings: L1 - 8 turns, L2 - 10 turns, L3 - 30 turns (in the ball) with a tap of 10 turns from below. The GPD L13 coil has 30 turns wound on the frame with a diameter of 6-8mm, the turn to the turn of the PEV 0.35 wire and placed in the screen.
C1 Caluation Condressor is small-sized from a pocket receiver with a solid dielectric. Capacitor C12 of a small-sized type with rotation bearings and a mechanical venier of any design is preferably with a slowdown of no more than 10 kHz per revolution of the adjustment knob.
As throttle, DR1 FNH is used one of the windings of the transformer LF from the pocket receiver. The K174UN4 microcircuit is equipped with a small cooling radiator.
KD522 diodes can be replaced with any silicon impulse, and D9 on any RF Germany. Instead of VD13, any rectifier diode can be used.
Range switch is a small-sized gallery type. The length of the connecting wires to quartz resonators should be shorter if possible.
When installing, the attenuator should be placed near T1.
Setup.
Contour settings frequencies:
L3, C7 - 6,25 MHz
L4, C8 - 6.0 MHz
L5, C9 - 6.5 MHz
L7, C28 - 500 kHz
L10, C35 - 500 kHz
The procedure for setting the radio is as follows:
connect the frequency meter or control receiver to C22 and the L13 core adjustment to set the frequency of the GPD overlap in the range of 5.5 ... 6.0 MHz. If necessary, for the "stretching" of the tank, set the concessor of a permanent container of the CT gray condenser with a variable condenser.
connect the RF Voltmeter to L11 and rotating the loop core L10 C35 to achieve its maximum reading;
connect the GSS to L6 and apply the RF is not a modulated signal with a frequency of 500 kHz,
variating the RF gain regulator, configure the core of the loop L7 C28 to the maximum of the luminescence of the S-meter LED and the sound of the beagi in the loudspeaker;
connect the GSS to the antenna of the receiver's nest, to sue the NF is not a modulated signal with the frequencies of setting up the first IF strip filter, according to the three frequencies of its circuits. Configure them at the maximum luminescence of the s-meter and the volume of the tone of the beats;
do not disconnect the GSS from the antenna, firstly, include 80 meter reception range and submit a test signal with the frequency of the middle of this range. Rotating the condenser's handle to find the resonance of the maximum level of reception. On the limb of the tincture of the input selector to make a mark on a visitor from the plexigla in the form of a zone of reception of the frequencies of this range. If necessary, adjust the core of the contour range coil, the resonance zone can be shifted at a convenient place to read from the limb;
the remaining areas of the ranges of 40m, 20m, 15m, 10a and 10b are marked on a limb with the correction of cores of the corresponding coils in the same sequence.
It is very convenient to have three sedimentary threads with adjustment zones: on the first closer to the axis of the condenser risks of 80 and 40 meters, on the second (medium) risks of the ranges of 20 and 15 meters, and on the third, with a large radius, the selector setting zone in 10-meter Range.
Excessive reinforcement of the PC 500kHz path can be compensated by the shunt resistor R9 or exclude it from the scheme at all.
When replacing the EHF elements C36 DR1 C37 C38 on the node of the active low-pass filter assembled on operating amplifiers and made in the form of a small-sized board located vertically on the main board, the electrical and operational characteristics of the receiver are significantly improved, as an improvement in real selectivity and a decrease in fater " white noise" (See my article: "Active low-pass filter for a coherent radio").
Tests of the receiver were carried out as follows.
1. Indoor on the table were installed: Transceiver TS-870., Radioisors DE1103. and Karlson.. The 1-meter antenna-wire is alternately connected to each of these devices when receiving the same radio station.
Comparative level of receipt of the signal is:
- TS-870 - 8 points
- Karlson - 7 points
- DeGen 1103 - at the level of internal noise.
2. On the table to the same outer antenna connected: TS-870 and Karlson. The signal level of the received control station and the comfort of ARU Karlson is not inferior to the factory apparatus, and with an explicit wins in a soft, analog sound.
3. Work was observed on the ether of the neighbor on the IC-718 and PA transceiver on the GU-74 located 500 meters from the reception site. At the same time, the "worst" ARU on Karlson is not observed, and the presence of a powerful local station is not felt outside the detuning more than 6 kHz.
4. With the disabled antenna, the maximum gain of the LF and the IF, the level of the internal noise of the Karlson receiver when working on a 0.5 W 8Ω speaker, does not pay attention to.
I will be grateful to see your feedback sent to the address.