Using the doublebalanced mixer DBM

Frequency Mixer Circuit Diagram

In radio-frequency electronics, a mixer is a nonlinear circuit or device that permits frequency conversion by the process of heterodyning. Mixers are used in the front end of the most common form of radio, the superheterodyne regardless of wave band , in certain electronic Instruments and in certain measurement schemes receiver dynamic range, oscillator phase noise, etc, . The block diagram for a basic mixer system is shown in Pig. i this diagram is generic in form, but it also represents the...

Universal IF amplifier

Cascade Amplifier

The IF amplifier in Fig. 8-5 is based on the popular MC- 1350P integrated circuit. This chip is easily available through any of the major mail order parts houses and many small ones. It is basically a variation on the LM-1490 and LM-159G type of circuit but is a little easier to apply. If you have difficulty locating MC-1350P devices, the exact same chip is available in the service replacement lines such as ECG and NTE. These parts lines are sold at 8-5 IF amplifier with crystal filter. local...

RF directional couplers

Build Directional Coupler

Directional coy piers are devices that will pass signal across one path while passijig a much smaller signal along another path. One of the most common uses of the directional coupler is to sample a RF power signal either for controlling transmitter output power level or for measurement. An example of the latter use is to connect a digital frequency counter to the low-level port and the transmitter and antenna to the straight-through high-power ports. The circuit symbol for a directional...

How To Make A 4-1 Balun On A Single Core

Impedance Matching Transformer

4-1S Inductive-loop dilution-finding antenna, where A is the length of each side in centimeters cm B is the width of the coil in centimeters cm N is the number of turns in the coil close wound ft and AT are 0.008, 1.4142, 0.37942, and 0.33113 respectively. Whenever conductors are placed side by side, as in the case of the loop-wound coil, there is a capacitance between the conductors even if formed by a single loop of wire, as in a coil . This capacitance can be significant when dealing with...

Some practical design approaches

Double Balanced Antenna

The literature on DCRs has several different popular approaches, anil each has its own place. Some of the simpler designs are based on the combination of a Signetics NE-602 device and a LM-386 IC audio section. Others are based on different 10 Rick Campbell, KK7B, -LHigh Performance Direct-C-onversion Receivers, QST. August i992 up 19-28. 11 ost August 1980, pp. 14-19 PaulG DauJton, K5WMS, The Explorer HF Receiver for 40 and Si Meters. 73 Amateur Radio 7bday, August 1992, pp 30-rt4 John Dillon,...

Introduction to negative resistance 1 devices

Gunn Diode Bias Circuit

Onant oscillator circuits use no tuning. They depend on the device dimensions and the average charge carrier velocity through the bulk material to determine operating frequency. Some NDR devices, such as the Gunn diode later in this chapter , will operate in either resonant or unresonant oscillatory modes. Transferred electron devices Gunn diodes Gunn diodes are named after John B. Gunn of IBM, who, in 1963, discovered a phenomenon since then called the Gunn Effect Experimenting with compound...

MOSFET preselector circuits

Varactor Tuned Vfo Circuit

7-6 MOSFET active preselector circuit. 7-6 MOSFET active preselector circuit. The inductors are of the same sort as described. It is permissible to put and Ls in close proximity to each other, but these should be separated from L4 in order to prevent unwanted oscillation because of feedback arising from coil coupling. The circuit in Fig. 7-7 is a little different. In addition to using only input tuning which lessens the potential for oscillation , it also uses voltage tuning. The hard-to-find...

Op Amp Vlf Converter Sales

Toko Rcl Ham Band Coil

Tuning circuit using one fixed and one variable inductor. 13-7 Mutual reactance coupling Ay capacitance and B inductance. In Fig. 13-7A, a small capacitance 33 to 120 pF is used to couple the two LC resonant circuits Li CiA and L Cib . In Fig. 13-7B, a common inductor Lf is used for the same purpose. Experiments show that a value of 150 to 700 iH is needed for The ARRL Handbook for Radio Amateurs all recent editions provides details on selecting values for the components in these circuits. A...

IF amplifier circuits

Amplifier Circuit

The IF amplifier provides most of the gain in a superhet receiver, and it also supplies the narrowest bandwidth in the signal chain. Thus, the IF amplifier is chiefly responsible for both the sensitivity and selectivity nf the radio receiver. In fancy radio receivers, the IF amplifier can be quite complex, as witnessed by the designs used in modern shortwave and ham radio receivers in the kilobuck range. This one is a con siderably simpler design, but is nonetheless effective. For those who...

Broadband RF amplifier 500 input and output

Amplifier Circuit

This project is a highly useful RF amplifier that can be used in a variety of ways. It can be used as a preamplifier for receivers operating in the 3- to 30-MHz shortwave band. It can also be used as a postamplifier following filters, mixers, and other devices that have an attenuation factor. It is common, for example, to find that, mixers and crystal filters have a signal loss of 5 to 8 dB this is called insertion loss . An amplifier following these devices will overcome that loss. The...

Broadband RF preamplifier for Vlf Lf and AM BCB

100khz 30mhz Preamp

In many situations, a broadband as opposed to tuned RF amplifier is needed. Typical applications include boosting the output of RF signal generators which tend to be normally quite low level , antenna preamphfication, loop antenna amplifier, and in the front ends of receivers. A number of different, circuits published, including some by me, but one failing that I've noted on most of them is that they often lack response at the low end of the frequency range. Many designs offer 3 dB frequency...