Hello Gordon
I have had some difficulties wit the VFO for the G6LBQ.
You can enter the VFO management mode. The specific doc you need
is likley in the files section. However, if it is not, I have
copied it below.
This is for the Ver 4.2 Firmware.
Top tips:? Once you have set the VFO Off set, ( likley 11.0592
MHz if you are using Xtals supplied by Andy) you will need to
calibrate the SILabs chip.
The instructions in the doc (and below) are difficult to
understand, so here's what you do:
1. Disconnect your VFO from the main board and connect its output
to a frequency counter that you know to be accurate.
2. Check you have the VFO Offset you wish to use, set up
correctly in the VFO.
3. Power off the VFO, power on and write down the displayed
frequency.
3. Enter the menus system and navigate to calibrate.
4. Adjust the VFO such that the displayed frequency on your
accurate counter (step 1) equals the frequency you wrote down in
step 3, by adjusting the tuning knob. This may take quite a? lot
of turning.,,,,,,
5. Once done, save & exit the menus system.
Note that there is a known "bug" in the software, well, known to
me that is, it exhibits it self as a the radio being slightly off
frequency more and more as you go higher in frequency. This is due
to the mathematics used in the VFO to manage the SiLabs chip and
inaccuracy in the chip itself. Its not much, but I found around 3
or 4KHz at 29MHz.
Hope that helps.
Adrian M1LCR
G6LBQ – Si570 Digital VFO Kit
Firmware Under Licence From PA0KLT
Last edited 25th May 2013
Operating instructions G6LBQ – Si570 VFO - V4.20 firmware
Seven push Buttons and the Rotary Tuning control are used to
operate the VFO
These are:
? Cursor <
? Cursor >
? Escape ESC
? Memory MEM
? RIT (Receiver Incremental Tuning)
? CLEAR
? LOCK
? TUNING (Rotary Encoder with switch used for fast tuning)
There are four modes of Operation
These are:
? VFO A (VFO A frequency - Manual tuning - Frequency Recal and
Store)
? VFO B (VFO B frequency - Manual tuning - Frequency Recal and
Store)
? Memory A (16 Memory Locations 1 - 16 to Recall or Store
Frequencies)
? Memory B (16 Memory Locations 1 - 16 to Recall or Store
Frequencies)
A Short push on "MEM" button switches between these four modes
VFO Mode A or VFO Mode B
? The Tuning speed - Frequency step is adjusted with < and
>CURSOR keys. The
frequency step can be set from 1 Hz, 10 Hz, 100 Hz, 1 kHz etc up
to 100 Mhz. The push
button on the Rotary encoder activates a fast tune option by
increasing the encoder
resolution by X25.
? One press on the RIT button enables RIT (Receiver Incremental
Tuning) and a second press
disables the RIT function. The total tuning range of RIT is +/-
10kHz. A press on the
CLEAR button resets the RIT frequency offset back to 0 kHz.
Page 1 continued on next page
? While in VFO Mode Pressing the ESC button sets all the digits
right of the curser to zero
? To store the displayed frequency in VFO mode to EEPROM, the MEM
key is pressed for 2
seconds until the LCD displays STORED
? Tuning to a frequency and pressing the MEM button for two
seconds stores that frequency
ready for the next time the unit is switched on. When in VFO use,
pressing MEM is only to
store the last frequency used in EEPROM. Setting that frequency
does not store it in any of
the 16 Memory locations.
Memory Mode
? Use a single quick press of the MEM button selects Memory A or
Memory B.
? When in Memory A or Memory B mode, press < > cursor
buttons to select the required
memory location (1 - 16). The previously stored frequency in the
selected memory location
is now displayed.
? When in the selected Memory location press the ESC button to
turn on Manual memory
tuning and tune to the frequency you want to memorise (store)
? When at the desired frequency press the MEM Button for 2 seconds
to store that frequency
? Press ESC sets all the digits right of the cursor to zero
Synthesizer Configuration Mode
The configuration menu's are accessed as follows:
? Press CURSOR < and > keys together for about 2 seconds
until the configuration menu
appears, release CURSOR keys and use CURSOR buttons < or >
to select Configuration
Options as described below. Store your selection by pressing the
MEM key.
Intermediate Frequency (IF) Offset Mode:
? Press MEM momentarily. Select the desired (IF Offset) using
CURSOR buttons and Rotary
encoder. The offset can only be a positive frequency so Si570
output (Local Osc) is higher
than IF Frequency. Press MEM to store the offset. Press ESC to
cancel.
By default the IF offset is set to 9mHz
Note 1. If an IF-Offset of less than <100 kHzis specified then
the IF-offset will be
removed with a delay of 5mS if the Lock (PTT) is activated by
grounding this line to earth.
Note 2. If an IF-Offset of less than <1 kHzis specified then
the 5 mS delay will not be
applied (as is the case for FSK)
Page 2 continued on next page
Calibration mode:
? Press MEM momentarily. The Si570's internal reference frequency
is now displayed and
may be changed so that the SI570 output frequency measured on a
counter is exactly as
displayed on the VFO LCD display. Once the corrected reference
frequency has been
selected press the MEM for 2 seconds to store the new value.
Multiplier (Si570 output frequency = (Displayed Frequency *
Multiplier)
? Press MEM momentarily and select the required multiplier factor:
2^0 for Multiplier 1,
2^1 for Multiplier 2, 2^2 for Multiplier = 4 and 2^3 for
Multiplier = 8. Press MEM for 2
seconds to store.
This option should be left at its default setting for the G6LBQ
multiband transceiver.
Default Configuration:
? If the configuration is corrupted for whatever reason the
default configuration settings may
be loaded in EEPROM. Press MEM momentarily. Press MEM for 2
seconds to confirm or
ESC to cancel
Set Maximum Frequency for Si570:
? The Si570 chip supplied with the G6LBQ multi-band VFO kit is
capable of operating up to
210MHz but this is not guaranteed. The upper frequency limit of
the VFO can be pre-set as
desired. When choosing the maximum frequency the plus IF frequency
must also be added
to the maximum wanted frequency. For example: the maximum
frequency needed for the
G6LBQ multi-band transceiver is 30 MHz, this along with an IF
frequency of 9 MHz
requires that we set the maximum frequency to 39 MHz. Press MEM
briefly and set
maximum frequency using rotary control and CURSOR < >
buttons. Press MEM for 2
seconds to store
or press ESC to cancel.
Minimum frequency for Si570:
? The minimum frequency which is supported by the Si570 and the
firmware is 3.50 MHz but
IF Offset needs to be taken into account. For Example if IF Offset
= 9 MHz and lowest
frequency required was 1.8 MHz then the minimum frequency should
be set to: (1.8+9) =
10.8 MHz
Configuring I2C address for the Si570:
? This option allows you to select the correct I2C address for the
AVR chip to
communicate with the Si570 chip. Si570 chips supplied by DX KIts
have address HEX 55.
Si570's from other suppliers may use a different address (for
example HEX 50). The
firmware allows you to specify any I2C address between Hex 50 and
Hex 5F. The default is
Hex 55.
Page 3 continued on next page
Si570/Si571 Selection:
? The firmware supports the Si570 & Si571 chips though DX Kits
only supply the Si570.
Selection of this option allows changes to be made to the value
for Kv. The default setting
for the Si570 is 0. If a Si571 chip is fitted then Kv should be
set to a starting value of 180.
Press MEM momentarily to access the Si570/Si571 selection. After
Kv value has been set
press MEM to store the new value or press ESC to quit this option.
END:
? When you have finished in the configuration mode return to VFO
mode with a single press
to the ESC button.
Complete Power-up Reset
On rare occasions the EEPROM data may become corrupted which could
prevent the VFO from
initializing properly and operating. Erasing EEPROM and applying
the default Configuration is not
possible and a Power-up Reset may be necessary as follows:
? Press ESC and MEM buttons at same time and apply DC Power until
the LCD Screen
shows the normal start-up screen. Release ESC and Mem buttons. Any
configuration
information previously applied will be lost and need to be
re-applied.
Page 4 End of manual
On 11/06/2020 11:49, Gordon Bowhay via
groups.io wrote:
toggle quoted message
Show quoted text
Hi, i need some advice on the G6LBQ digital VFO. The firmware
version is 4.2. I recently built this after having the components
in a drawer for some years. The Xtals in the exciter are 11 MHz
and so I want to put this in as the offset which I can do. Then
the highest frequency which I can extract from the synthesizer is
27.9MHz.If I remove the IF offset I can only tune up to 39MHz. It
would appear that the firmware was intended to match an exciter
with a 9 MHz Xtal filter. Is there a way around this problem? What
is preventing a higher frequency from being extracted? Thanks in
anticipation.
Gordon
