FD - 01 Display Module
Looking for an advanced digital dial for that next project? How about a versatile bench top 100MHz frequency counter?
Introducing the FD-01!
Only £59.95 inclusive of VAT
(£51.02 Exclusive of VAT)
(£51.02 Exclusive of VAT)
To order by post, please use our order form which can be downloaded from the ordering page.
Feature packed display module that operates from VLF to VHF. Ideal for integration into radio transceivers or for use as a stand alone piece of test equipment. Fully programmable IF Offsets and Multiplier Functions support applications in single conversion, direct conversion or multi-conversion single band transceivers.
Features
|
 |
 |
FD- 01 Frequently Asked Questions
How does the S Meter work?
There are two analogue inputs on the FD-01 associated with the S Meter. One input measures the AGC Bias voltage the other measures the AGC voltage. For flexibility, each input has a 100k pot to set input level and has a minimum full scale deflection (9+50dB) of just over 2.4 volts. Diode protection prevents damage to the FD-01 should this be exceeded. The ability to capture the bias point is important for AGC systems that have a DC AGC component at maximum gain (no input signal detected). For systems with positive going AGC, e.g. MC1350 IF amplifiers, the Bias and AGC connections are made in one direction, for IF systems that employ a negative going AGC, e.g. Dual Gate Mosfet IF stage, the Bias and AGC connections are simply reversed. The FD-01 calculates the difference between the AGC Bias voltage and the AGC voltage. The resultant value is the dynamic AGC range and it is this that drives the S Meter display. The S Meter display is a linear bar graph with each bar representing 1 'S Point' (6dB). The dB relationship holds true for the S9+ values. The accuracy is a function of the linearity and calibration of the host equipment's AGC characteristics.
How does the basic bar graph option operate?
A single analogue input is used to drive the plain Bar Graph. This has been provided as a useful linear voltage measurement tool that users can apply to many applications. The full scale input voltage is just over 1.5 volts, minimum is zero volts. Voltages in this range are represented linearly by 12 blocks on the bar graph. Diode protection prevents damage to the FD-01 should this be exceeded. The input impedance is 100k, no input level adjustment is provided as this feature may serve several measurement points each with their own potential divider to set the maximum level presented to the FD-01. Typical applications might be used to represent transmitter output power from a diode voltage sampling point, or show battery state in portable equipment. The availability of the plain Bar Graph is driven by the Transmit/Receive control input. The logic is as follows;
Rx Meter is user selectable between S Meter and Bar Graph
Tx Meter automatically switches to Bar Graph
What is Tx to Rx Hold Off Delay?
We've added this feature at the request of the CW enthusiasts. The delay, sometime referred to as Hysteresis, is not an actual slowing or halting of the FD-01 processes, but a delay in changing the appearance of the display from Tx to Rx. This is useful in full break in applications where the host transceiver is switching between transmit and receive with every key stroke. Without Hold Off, the FD-01 display would follow these fast state changes presenting rapidly changing display information. The Hold Off keeps the display in Tx mode during keying, showing the user defined Tx configuration (frequency with offset and mult factor if configured), the Bar Graph for Tx output display and the Tx indicator. After a user definable delay, once keying stops the display reverts to Rx mode.
This is digital electronics, will it interfere with my receiver?
The FD-01 is surprisingly quiet. Great care has been taken to minimise PCB signal track lengths and plenty of decoupling has been provided. The LCD runs at very low power, the signal currents flowing along the interface cable and the field they generate are also very low. Even if you place an unscreened MW/LW transistor radio with a ferrite rod antenna alongside an FD-01 it is difficult to identify interference- and this is not a realistic situation! Providing that you employ good installation practices, and ensure that your host receiver input and IF stages are adequately screened, then you should not notice any noise contribution.
Only £59.95 inclusive of VAT
(£51.02 Exclusive of VAT)