|
SWEEP DOCUMENTATION
The
first part is to discuss the specifications of the software so
that you can determine if Sweep software is suitable for
your application.
The PIC Source code may be available for
those that may want to change things to suit their own application
We ask that any changes to the software be available to all other
Ham Radio operators through Mini-Kits for free.
DDS
VFO BLOCK DIAGRAM Download Updated 31/1/2012
SweepGen Ver2.0x ( Readme Document for the Sweep Kit ) Download Updated 31/1/2012

SWEEP
Ver 2.0x SOFTWARE ( What Will The Software Allow You To Do )
Although no problems have been found with
the final Software version 2.0x since November 2007, Mini-Kits
takes no responsibility for faults & minor glitches in the
Software supplied with Kits.
Below
are the standard specifications for the SweepGen ver2.0x software
supplied by Mini-Kits. The PIC Source code may be available for
those that may want to change things to suit their own application
We ask that any changes to the software be available to all other
Ham Radio operators through Mini-Kits for free.
WHAT WILL THE SWEEP GEN SOFTWARE ALLOW YOU TO DO?
Refer to the Software Notes for
more detailed information Use, Download the Sweep Readme document.
The Software is designed to be used
for a simple signal generator, but also has an inbuilt sweep function
with the addition of the Power Head Kit can also measure RF Power in
dBm, Watts, Volts. Standard functions are Frequency Tuning, Step Size,
Calibrate, Memory, Sweep Direction, Sweep Start Stop, Sweep speed, Fast
Sweep, VFO/Sweep mode. The signal generator output can be used at the
same time as reading RF from one of the Power Head Kits. So a filters
3dB BW can be measured by tuning the DDS generator by hand looking for
the -3dB points of the filter. The Sweep function is only suitable for
use with either a Spectrum Analyzer or Oscilloscope with a RF probe
as the sweep is too fast for the power head kits to read. Currently
there is no trigger pulse available from the sweep generator for locking
of an Oscilloscope.
The software does not allow for
any display offset or Transceiver Radio functions, as it has been designed
to make a useful piece of test equipment.
BASIC SOFTWARE SPECIFICATIONS
1/ Frequency range programmable
from a minimum frequency of 1Hz, to a Maximum output frequency of 70MHz,
( Using a Osc4 30MHz osc module & DDS x6 multiplier
).
2/ Variable Rate Tuning & Adjustable
Step Size 1Hz, 10Hz, 100Hz, 1kHz, 10kHz, 100kHz, 1MHz, 10MHz, 100MHz,
1GHz etc
3/ Programmed to use a low cost
Mechanical Rotary Encoder.
4/ Software fine tuning of the Reference
oscillator frequency.
5/ Programmable for various Reference
oscillator frequencies & DDS x1 or x6 Multiplier.
6/ Up to 11 Sweep Generator Memories
can be programmed, ( Including start & finish
frequency, & sweep rate ).
7/ There are two Sweep modes Slow
& fast, in each there are 10 sweep speeds. Please refer to the Readme document for
more detailed information on the sweep width & speeds.
8/ Memorises the last frequency on power up.
7/ Calibration menu to program optional
Power Head Kits.
8/ Programmable menu to set for
when using an input attenuator or amplifier on the Power Head.

CONSTRUCTION:

| |
The above picture shows the DDS VFO hardware with Sweep software mounted in a Takachi Aluminium Box ( 150x100x120mm ) RS Components 401-8982.
The front panel was cut out using a nibbling tool & filed with a
very fine metal file. |
|
| |
|
|

KIT
FAULTS & MODIFICATIONS ( Older EME85 DDS Version Hardware )
1/ Refer to the EME85
DDS Kit webpage for some possible problems.
2/ Most Faults can be traced
to poor solder joints, or solder bridges across connections. Check
for correct wiring to the control board & LCD display module.
3/ Low RF output on frequencies
lower than 15MHz is normally incorrectly fitted 10nF chip capacitors
on the input & output of the MAR6 amplifier. Some constructors
have accidentally put 10pF capacitors in place.
4/ Some have reported that when
using the Power Head kit on the Sweep Kit that the 0.1dB reading
flashes erratically on the LCD & cannot be read. The display
will normally change between 0.1dB steps as the meter display accuracy
is 0.25dB per step but can be quite easily read. Most problems with
this, has been traced to a noisy 12 volt supply to the Sweep Kit.
Make sure that you use a well regulated 12 volt Power Supply. The
problem only shows when using the DDS RF output & is not a problem
with another RF signal generator. I suspect that this is due to
the MAR6 on the DDS board generating the noise on the RF due to
there being no regulator on its supply.
5/ If you are getting erratic letters &
numbers, ( Garbage ) on the LCD, disconnect everything from the
DDS board excluding the LCD first. If the LCD is still showing the
same garbage on the display, then the software in the PIC is probably
corrupted & needs reprogramming. There
has been one report of this.

|
This
and all subsequent pages copyright 1999 - 2012 by Mini-Kits
All rights reserved |
|
|