Standard frequency and time transmissions, Boundaries of sea areas and UK CB radio.

By -

Standard frequency and time transmissions

image

Standard frequency formats

image

Boundaries of sea areas

As used in BBC and BT weather forecasts

Stations whose latest reports are broadcast in the 5 minute forecasts on Radio 2 (200 kHz) at 0033, 0633 and 1755 (daily), 1155 (Sundays) and 1355 (weekdays).

image

The SINPFEMO code

image

The SINPO code

image

The SIO code

image

image

BBC AM radio stations

image

image

UK CB radio

27 MHz band: 27-60125 to 27-99125 MHz.
40 channels at 10 kHz spacing.
Max. e.r.p. 2W; max. transmitter output 4W.
Aerial: single rod or wire, l-5m overall length, base loaded. If mounted higher than 7m, transmitter output to be reduced at least lOdB.
Modulation: F.M. only, deviation ± 2-5 kHz max.
934 MHz band: 934 025 to 934-975 MHz.
20 channels at 50kHz (may be reduced to 25 kHz later). If synthesizer used spacing may be 25 kHz on precise channel frequencies specified.
Max. e.r.p. 25 W; max. transmitter output 8W; if aerial integral, max. e.r.p. 3 W.
Aerial: may have up to four elements, none exceeding 17cm. If mounted higher than 10m, transmitter output to be reduced at least lOdB.
Modulation: FM only, deviation ± 5 0kHz max.
Spurious emissions: For both bands, not exceeding 0·25ìë¥, except for specified frequency bands where the limit is 50nW.
For full specifications see publication MPT 1320 (27 MHz) and MPT 1321 (934 MHz) from HMSO.

image

 

Comments

Post a Comment

Popular posts from this blog

Square wave oscillators and Op-amp square wave oscillator.

By -
Image
Square wave oscillators If Fourier analysis is performed on a square wave it is found that the waveform is composed of many harmonics of the fundamental frequency. This rich harmonic content makes the square wave particularly useful as a quick test of amplifier performance. Examples of possible results are shown. The simplest way to produce a square wave is to make a sine wave oscillator in one of the ways described earlier, then feed the output to some form of squaring circuit such as a Schmitt trigger. This is the method adopted in most commercial sine/square wave generators. There are, however, several circuits for square wave oscillators and a description of the most common follows. Multivibrator Technically the multivibrator is a relaxation oscillator, working on the charging of a capacitor through a resistor. If a negative edge is applied to the circuit in (a), transistor TR 1 turns off the for time taken for the base voltage to return to 0 V. If the voltage step is
Read more

Adders:Carry Look-Ahead Adder.

By -
Image
Carry Look-Ahead Adder As previously stated, the carry, c i +1, produced at the i -th position is calculated as c i +1 = x i · y i ∨ c i ·( x i ⊕ y i ). This means that a carry is generated if both x i and y i are 1, or an incoming carry is propagated if one of x i and y i is 1 and the other is 0. Therefore, letting g i denote x i y i , we have c i +1 = g i ∨ c i p i , where p i = x i ⊕ y i . Here, g i is the formula for the carry generation condition at the i -th position, i.e., when g i is 1, a carry is generated at this position. Substituting g i –1 ∨ p i –1 c i –1 for c i , we get A carry look-ahead adder can be realized according to this expression, as illustrated in Figure 41.10 for the case of four bits [21]. According to this expression, c i +1’s are calculated at all positions in parallel. It is hard to realize an n -bit carry look-ahead adder precisely according to this expression, unless n is small, because maximum fan-in and fan-out restriction is violated at higher
Read more

Timing Description Languages:SDF

By -
Image
SDF Standard Delay Format (SDF) is an ASCII format used to convey timing information between EDA tools. SDF was first developed by Cadence in 1990. Open Verilog International (OVI) approved SDF version 2 in 1993 and SDF version 2.1 and 3 in the following years. Improving SDF version 3 features, resulted in IEEE Standard 1497 [1]. Role of SDF in Design Process SDF can be used in different levels of a design process to annotate timing specifications, including timing data and constraints. Timing constraints are used during the forward-annotation process while timing data are applied during the back-annotation process. Forward-annotation process deals with porting timing constraints to synthesis, floorplanner, layout, and routing tools to meet the required constraints. During the design process, timing data can be back-annotated to analysis tools (including simulators, static timing analysis tools, etc.) to provide more accurate timing representations. SDF Structure An SDF f
Read more