Refinement of the DPKD of the RA3AO transceiver with an arbitrary IF. Scheme, description

Free technical library

ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING
Free library / Schemes of radio-electronic and electrical devices

Refinement of the DPKD of the RA3AO transceiver with an arbitrary IF. Encyclopedia of radio electronics and electrical engineering

Free technical library

Encyclopedia of radio electronics and electrical engineering / Civil radio communications

Comments on the article

Most radio amateurs are deprived of any choice at all and apply quartz filters to the most arbitrary frequencies. In this case, it is necessary to recalculate the DPKD coefficients and change the electrical and wiring diagrams of individual nodes.

In the general case, calculations are reduced to determining fmin - fmax GPA, providing coverage of all ranges. It should be noted that this can not be achieved for all IF values. In this case, you have to make a compromise - to refuse any range (part of the range) or increase the tuning density. Based on the value of the IF, we determine the boundaries of the GPA tuning for each range of fgpd at the output of the DPKD. The obtained values are successively multiplied by a series of numbers "K" = 5,6,7...40. We write out all the multiplication results that are in the range from 100 to 210 MHz in the form of a table, indicate "K" on top, by multiplying by which the result is obtained. The use of frequencies up to 100 MHz is unlikely, and 210 MHz is the limiting frequency of ESL logic in DPKD. After filling in the entire table, you can quickly select options that allow you to cover all ranges with a minimum restructuring of the GPA.

Particular attention should be paid to IF frequencies that are close to the band boundaries. For example, if IF = 13 MHz, then for the 20 m band, the probable "K" will have values from 100 to 200. It is obvious that such "K" cannot be implemented in the existing DPKD scheme.

In this case, you can use the inverse conversion, i.e.: (fgpd at the DPCD output) + (14,0-14,35) + 13-27,35 MHz, then the calculation of "K" is as usual. But with this option, two unpleasant circumstances must be taken into account:

- "coup" lateral, which is easily eliminated by pressing the U / L button after switching to this range;

- the frequency meter begins to count "vice versa", which is eliminated by altering the PKU board (the circuit for issuing a U / L signal to the CTM board).

To provide a set of necessary "K", changes are made to the electrical and, accordingly, the wiring diagrams of the DPKD. The data selected as an example, corresponding to fp = 8.33 MHz, are entered in Table 1.

Table 1
Dr. "TO" KD1 Log."1" to: KD2 Log."1" to: "+ 1" Log."1" on
160 14 7 VT4, VT5 2 not under. no not under.
80 12 6 VT4 2 not under. no not under.
40 9 4 VT3 2 not under. "+ 1" VT8
30 10 5 VT3, VT4 2 not under. no not under.
20 24 4 VT3 6 VT7 no not under.
16 14 7 VT4, VT5 2 not under. no not under.
15 11 5 VT3, VT4 2 not under. "+ 1" VT8
10 7 3 VT3, VT6 2 not under. "+ 1" VT8

Compared with Table 5 in (L), columns have been added to it, in which DPKD transistors are indicated, on the bases of which control is applied to obtain the necessary KD1, KD2. It can be seen from the table that all the necessary "K" are obtained using the dividers available in the original DPKD circuit, i.e. the changes will affect only the base circuits of transistors VT3 - VT8.

Based on table 1, we draw a part of the DPKD electrical circuit that is subject to changes (Fig. 1). Next to the transistors, the KD1 and KD2 controlled by them are indicated.

Refinement of the DPKD of the RA3AO transceiver with an arbitrary IF
Ris.1

The alteration of the A6 board is as follows: a part of the printed conductors laid from the contacts A3, B4, A4, B5, A5, B8, A8, B9 of the XP1 plug to the resistors R24 - 36, R44 - 48 is removed. 0,12, the conductors are attached to the board with glue. The necessary changes are also made on the part of the bases of transistors VT3 - VT8. When setting up the DPKD board, it is more convenient to "run" in one range, soldering the necessary resistors and each time checking the correct division of the DPKD. To facilitate the installation of "+1 '', it is useful to do the following: mount resistors R42, R54, R67 from the side of the printed conductors, and install PDA trimmers 11-15 pF on top of the board instead of C4, C15.

Solder the "hot" ends of the trimmers directly to pins 11 DD6 and 6 DD5. Adjust according to (L).

If the transceiver is not intended to work together with an additional receiver, you can connect the 4,5 DD6 pins together; do not lay conductors coming to contacts B12, B14, B15 of socket A6, and use node A15 for other purposes.

Changes on boards A2, A4, A19 are reduced only to changing the settings of the circuits. Programming the IF value on the A7 board is detailed in (L).

Literature

1. V. Drozdov "Amateur KB transceivers".

Author: F.Sharapov (RA4PC), Leninogorsk; Publication: N. Bolshakov, rf.atnn.ru

See other articles Section Civil radio communications.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

A New Way to Control and Manipulate Optical Signals 05.05.2024

The modern world of science and technology is developing rapidly, and every day new methods and technologies appear that open up new prospects for us in various fields. One such innovation is the development by German scientists of a new way to control optical signals, which could lead to significant progress in the field of photonics. Recent research has allowed German scientists to create a tunable waveplate inside a fused silica waveguide. This method, based on the use of a liquid crystal layer, allows one to effectively change the polarization of light passing through a waveguide. This technological breakthrough opens up new prospects for the development of compact and efficient photonic devices capable of processing large volumes of data. The electro-optical control of polarization provided by the new method could provide the basis for a new class of integrated photonic devices. This opens up great opportunities for ... >>

Primium Seneca keyboard 05.05.2024

Keyboards are an integral part of our daily computer work. However, one of the main problems that users face is noise, especially in the case of premium models. But with the new Seneca keyboard from Norbauer & Co, that may change. Seneca is not just a keyboard, it is the result of five years of development work to create the ideal device. Every aspect of this keyboard, from acoustic properties to mechanical characteristics, has been carefully considered and balanced. One of the key features of Seneca is its silent stabilizers, which solve the noise problem common to many keyboards. In addition, the keyboard supports various key widths, making it convenient for any user. Although Seneca is not yet available for purchase, it is scheduled for release in late summer. Norbauer & Co's Seneca represents new standards in keyboard design. Her ... >>

The world's tallest astronomical observatory opened 04.05.2024

Exploring space and its mysteries is a task that attracts the attention of astronomers from all over the world. In the fresh air of the high mountains, far from city light pollution, the stars and planets reveal their secrets with greater clarity. A new page is opening in the history of astronomy with the opening of the world's highest astronomical observatory - the Atacama Observatory of the University of Tokyo. The Atacama Observatory, located at an altitude of 5640 meters above sea level, opens up new opportunities for astronomers in the study of space. This site has become the highest location for a ground-based telescope, providing researchers with a unique tool for studying infrared waves in the Universe. Although the high altitude location provides clearer skies and less interference from the atmosphere, building an observatory on a high mountain poses enormous difficulties and challenges. However, despite the difficulties, the new observatory opens up broad research prospects for astronomers. ... >>

Random news from the Archive

Plants sense and react to root temperature 23.07.2023

Scientists at the University of Halle-Wittenberg in Germany have found that plant roots have the ability to perceive and respond to soil temperatures independently of the rest of the plant. This discovery highlights that roots not only transmit signals up the stem, but can themselves respond to changes in the environment.

Previously, it was believed that the roots of plants are not able to respond to the environment on their own and exclusively obey the signals coming from the stem. However, new experiments with plants such as the common caterpillar, tomatoes and cabbage, carried out at a controlled temperature increase from 20 to 28 degrees Celsius, disproved these ideas.

As the soil temperature rises, the cells at the ends of the roots begin to divide more actively, which leads to the elongation of the roots. Cutting the stems has no effect on this process. In addition, scientists conducted experiments with genetically modified plants that had a disrupted system for responding to high temperatures in the stem. Even in these "defective" plants, the roots still responded to temperature, confirming their independent reaction.

Biochemical analyzes have shown that as soil temperatures rise, roots begin to produce more of a growth hormone known as auxin. This hormone travels to the root tip, where it stimulates cell division and promotes cell elongation, allowing roots to penetrate cooler, wetter soil layers. "High temperature and drought usually go hand in hand, so it's natural for plants to tend to go deeper, where there's more moisture," explains Prof Quint. It is possible that plants also exchange chemical signals through their roots, communicating changes with neighboring plants.

With an increase in temperature, auxins are also synthesized in the stem, but the reaction of plants to them is completely different. In response to the hormone, plants elongate their cells, making stems and leaves thinner and narrower to minimize moisture loss. Understanding these mechanisms will make it possible to better predict how climate change may affect the plant world, especially agriculture, on which the productivity of crops and, consequently, the food security of mankind depends.

Understanding the mechanisms by which plants respond to temperature changes is of great importance for the development of sustainable agronomic practices and plant varieties that can effectively adapt to climate change. For example, crops with improved ability to perceive and respond to temperature can make more efficient use of available resources such as water and nutrients, which can help reduce the negative impacts of climate change on agriculture.

A closer examination of the relationship between plant roots and temperature will help expand our knowledge of plant physiology and adaptive capacities. This will enable the development of innovative methods of tillage, irrigation management and plant breeding that are resilient to climate change, and contribute to the development of sustainable and productive agriculture in the future.

Other interesting news:

▪ Laser projector Panasonic PT-CMZ50

▪ mechanical dragonfly

▪ Global organic shutter image sensor

▪ GPU chip design

▪ Destruction of the tumor from the inside

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the site Art video. Article selection

▪ article Accounting. Lecture notes

▪ article Why is one of the proteins in the human eye named after Pikachu? Detailed answer

▪ article Operator of a mobile concrete mixer. Job description

▪ article Amplifier on a TDA7245 chip, 5 watts. Encyclopedia of radio electronics and electrical engineering

▪ article About the Radio-76 transceiver. Encyclopedia of radio electronics and electrical engineering

Leave your comment on this article:

All languages of this page

Home page | Library | Articles | Website map | Site Reviews