| FD-SWM-HF
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Test Reports:
Measuring
SWR at HF from 1MHZ to around 60MHZ was
always a concern to radio amateurs. Till today, thousands of radio
amateur run their station without an SWR Meter, without knowing matching
between their Tx and the Ant.
SWR
Meters of Analog variety are planty, although, not very economical.
LCD meters are more expensive, crossing a range of over $140.
LCD
SWR Meter presented here meet many simple task using a PIC16F877A
micro controller. The very basic purpose to make this project is to
encourage radio amateurs to build their own SWR Meter at very low
price.
Following
task achieved thru this design:
1. Simple single Micro Controller with built-in A/D converter.
2. Simple single Toroidal Core HF Bridge
3. Back light control
4. SWR, FWD, POWER and Actual Power to antenna
calculations/Display.
5. Bargraph mode for SWR & Forward Power
6. Compact Design
7. May be powered from DC9V battery or 12V DC
Project
Bases:
Project
is developed on two double-sided PTH boards. The first one is CPU
board where LCD, Regulator and Back Light Controllers are located.
This board receives pure DC level from sensor board for calculation
& display.
The
second board is RF Sensor Bridge, where power from your transceiver
comes in and goes out to antenna. It is a simple HF Toroidal Bridge
design using BAT85 diodes.
Although
SO239 types of connectors are used, there is no reason why you
cannot use N type connectors. They will fit nicely on four mounting
holes available for SO239 sockets.
Kit
is intended for experienced Radio Amateurs. Later, I will try to
supply assembled units too.
Although,
rated at 100W HF, this meter & bridge worked very well at a KW
and above, on all bands. Readings were very accurate compared to
Bird SWR Meter.
However,
it should be noted that, the Display Unit Firmware is limited to
100W maximum. Means, if you wish, you may set bridge presets to
measure 1KW but meter will display 100W on LCD.
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