Homemade HF receiver for amateur bands: circuit

Homemade HF receivers (short wave) are made on the basis of resistor switches. Many modifications include a wired adapter and are equipped with amplifiers. The standard scheme has stabilizers of increased frequency. To adjust the channels, adjusters with lining are used.

It should also be noted that the receivers differ in the conductivity and frequency of the tetrodes. In order to thoroughly understand this issue, we need to consider the schemes of the most popular receivers.

Low-frequency devices

The scheme of a self-made HF receiver of a low frequency includes a controlled modulator, as well as a set of capacitors. Resistors for the device are selected at 4 pF. Many models have contact triodes that operate on converters. It should also be noted that the receiver circuit includes only single-pole transceivers.

To adjust the channels, the knobs are used, which are set at the beginning of the chain. Some models are made with only one adapter, and the connector for them is selected as a linear type. If we consider simple models, then they use a grid amplifier. It works at a frequency of 400 MHz. Isolators are installed behind the modulators.

Lamp models of high frequency

Self-made tube HF receivers of high frequency include contact converters and sensors with low conductivity. Some experts respond positively to these devices. First of all, they note the possibility of connecting transceivers. Triggers for modifications are suitable for controller type. The most common devices are semiconductor resistors.

If we consider the standard scheme, then the comparator is of an adjustable type. Resistors at the output are installed with a capacity of at least 3.4 pF. Conductivity is not lowered below 5 microns. Regulators are installed on three or four channels. Most receivers use only one phase filter.

Pulse modifications

A pulsed self-made HF receiver for amateur bands is capable of operating at a frequency of 300 MHz. Most models are stacked with contact stabilizers. In some cases, transceivers are used. The increase in sensitivity depends on the conductivity of the resistors. The capacitance of the capacitors at the output is 3 pF.

Conductivity of contactors on the average is 6 microns. Most receivers are manufactured with dipole adapters, which are suitable for PP connectors. Very often there are condenser units that operate on thyristors. If we consider models on lamps, it is important to note that they use unijunction comparators. They are switched on only at a frequency of 300 MHz. Also I must say that there are models with triodes.

Single-pole devices

It is easy to configure exactly single-pole homemade tube HF receivers. The model is assembled with variable comparators by its own hands. Most modifications are designed with low-conductivity stabilizers. The standard receiver circuit assumes the use of dipole resistors, in which the output capacitance is equal to 4.5 pF. The conductivity can be up to 50 microns.

If you independently collect the modification, then the comparator must be harnessed with the transceiver. Resistors are soldered to the modulator. The resistance of the elements, as a rule, does not exceed 45 Ohm, but there are exceptions. If we talk about receivers on the relay, then they use adjustable triodes. These elements work from the modulator, and they differ in sensitivity.

Assembling multipolar receivers

What are the advantages of a multipolar detector HF receiver for amateur bands? If you believe the experts' opinions, these devices produce a high frequency and at the same time consume little power. Most modifications are assembled with dipole contactors, and the adapters are of the wired type. The connectors for the devices are suitable for different classes.

Some models contain phase filters that reduce the risk of failure from wave interference. It should also be noted that the standard receiver circuit assumes the use of a regulator to adjust the frequency. Comparators for some instances are of channel type. In this case, the triode is used only with one insulator, and its conductivity does not drop below 45 microns. If we consider receivers on expanders, then they are able to operate only at low frequencies.

Models with a two-transducer

KV receivers for amateur bands with two-junction converters are able to stably maintain the frequency at 400 MHz. Many models use a polystyrene pole. It operates from a converter and has a high conductivity. The standard modification scheme includes a controller for three outputs and a capacitor. The amplifier for the model is suitable with a varicap.

It should also be noted that high-frequency devices with a converter of this type can perfectly cope with the impulse noise from the unit. Comparators are used with grid and capacitive resistors. The resistance parameter at the input of the circuit is about 45 ohms. In this case, the sensitivity of the receivers can be very different.

Devices with a three-wire converter

A homemade HF receiver for amateur bands with a three-wire converter has one contactor. The connectors are used with and without an overlay. It should also be noted that the resistors are of different conductivity. At the beginning of the chain there is an element of 3 microns. As a rule, it is of the single-pole type and transmits current in only one direction. The capacitor behind it is located with a linear conductor.

It should also be noted that the resistors at the output of the circuit have low conductivity. In many receivers, they are of a variable type and are capable of passing current in both directions. If we consider modifications at 340 MHz, then you can find comparators with grid triodes. They work at increased resistance, and the voltage is as much as 24 V.

Modifications to 200 MHz

Homemade HF receiver for amateur bands with a frequency of 200 MHz is very common. First of all, it should be noted that the models are not capable of working on comparators. Linear modifications are often encountered. However, the most common devices are considered to be models with transitional decoders. They are installed with a set of adapters. Resistors at the beginning of the circuit are of high capacity, and their resistance equals at least 55 ohms.

Amplifiers meet with filters and without them. If we consider commutated modifications, then they use duplex capacitors. The stabilizer is used with the regulator. To configure the channels, you need a modulator. Some receivers work with receivers. They have a PP series connector.

300 MHz devices

Homemade HF receiver for amateur bands with a frequency of 300 MHz includes two pairs of resistors. Comparators in the models meet with a conductivity of 40 microns. Some modifications contain wire expanders. These elements can significantly relieve the load from the capacitors.

If you believe the responses of experts, then the models of this type are distinguished by increased sensitivity. Homemade devices are manufactured without tetrodes. To improve the conductivity of the signal, only transistors are used. Also it should be noted that there are devices with channel filters.

Modifications to 400 MHz

The scheme of the device at 400 MHz involves the use of a dipole adapter and a network of resistors. The transceiver for the model is used with an open filter. To assemble the device with your own hands, the tetrode is first prepared. Condensers under it are torn by low conductivity and sensitivity at 5 mV. Also it should be noted that receivers with low-frequency converters are considered to be the most common devices. Next, to assemble the device with your own hands, one modulator is taken. This element is set before the converter.

Lamp devices of low sensitivity

Lamp HF receiver for amateur low sensitivity ranges is able to work on different channels. The standard scheme of the device involves the use of a single stabilizer. In this case, the adapter is of the open type. The conductivity of the resistor must be at least 55 microns. It is also important to note that the receivers are manufactured with plates. To assemble the device by hand, a set of capacitors is prepared. The capacity at them is obliged to make not less than 45 pF. It is especially important to note that receivers of this type are distinguished by the presence of duplex adapters.

Receivers of high sensitivity

The high-sensitivity device operates at a frequency of 300 MHz. If we consider a simple model, it is assembled on the basis of a comparator with a conductivity of 4 microns. In this case, filters for it are allowed to be applied with an overlay.

Transistors to the receiver are mounted uni-directional, and filters are used at 4 pF. Wired transceivers are quite common. They have good conductivity and do not require large power inputs.

The modulator may only be used with one varicap. Thus, the model is able to work on different channels. To solve problems with negative resistance, an expansion capacitor is used.