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June 12, 2015: Boxed and ready |
| Exterior/Interior |
| Front Panel | ||||
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| Front panel (power on) | ||||
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| Internal photo (before each unit is installed on the main board) | ||||
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| Internal photo (each unit installed on the main board) | ||||
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| SMeter Initial startup display Normal operation |
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| The S meter is a cheap 100uA device, but it can display electric fields from weak to strong. I created a sticker and illuminated it with a wheat bulb. The S meter has 1 step = 5dB. | When the power is turned on, the initialization display appears for about 1 second. | There is one incomprehensible display, but this is not a bug. Since AGC = Slow/First has been added, Slow = ON, First = OFF. |
| Each block produced |
| DISPLAY+CPU DDS POWER |
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| The display is not an LCD but an EL display, so there are no problems with viewing angles and there is no persistence like with LCD. The CPU is a removable unit that can be inserted from the back of the DISPLAY board. | It is equipped with two receivers, and an SG is installed inside to adjust each block and check the characteristics. It is equipped with four DDS (10bit-DAC) + a DDS (12bit-DAC) for VFO for a total of five. The nuclear clock is 27MHz (locked with an external reference of 10KHz). | Power supply unit for the entire system (±12V, ±5V and +5V/+3.3V for digital supplies) |
| Filter Unit AF-AMP Allpass Filter |
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| You can switch between three types: Rockwell Collins mechanical filter (2.5KHz and 4KHz) and Murata ceramic filter (10KHz). The 10KHz filter is required for receiving ISB radio waves. | The headphone jack/HP-VR/SP-VR are integrated so that they can be directly exposed to the panel surface. The speaker amplifier/headphone amplifier/meter drive circuit are also included. | The all-pass filter has 8 stages for the main route and 6 stages for the monitor route, but 4 to 6 stages will be sufficient. |
| Main Unit FL and AFPSN implemented whole |
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| ANT signal input, all-band RF block + IF (AGC) + detection block | The IF filter and AFPSN are mounted as a unit on top of the main board. | The entire unit looks beautiful in this state, but becomes messy once wired. |
| Some features |
| IF-Shift function |
| This function shifts the filter characteristic curve left or right (up or down ±999Hz) around the carrier point to remove interference. Ideally, it should be arranged in 3KHz steps, but since this is amateur radio, there are often overlapping signals with wide bands. In such cases, if you use this function in combination with reception in the Nar band (2.5KHz), you can remove some of the interference. |
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| SG function |
| Pressing the 'SG' button switches to SG mode, and the frequency of the currently received carrier point is input to the ANT terminal at S9+50dB. Also, if ATT=ON, the ANT terminal will be S9+30dB, allowing two types of strength input. The SG frequency can be output at any frequency, either above or below. This means that this unit does not require any special measuring equipment, and you can check the characteristic curves of each block, and perform reverse side and level adjustments all with just an oscilloscope. |
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RIT
function  |
F_LOCK
Function  |
| Although frequency stabilization is no longer an issue with recent devices, it can sometimes be a concern even during actual QSOs with slightly older devices. In my actual operation, it was still necessary, so I added this function. When you press the 'RIT' button, your transmission frequency is fixed, and you can freely shift the receiving frequency after that. While this function is active, the transmission frequency and receiving frequency are independent. | Until now, the rotary encoder I used for my own creation was a cheap mechanical 25 pulse/revolution part from Akizuki, but for digital tuning, you want to tune in a mode with a small step number, for example 100Hz step or less, but in this case, an encoder with a large number of pulses per revolution is required. To get a feeling close to that of an analog VFO, you want to tune in 10Hz steps, but it is difficult to find an optical part with a large number of pulses per revolution (250 or 500) that is also inexpensive. This time, I found an optical encoder with 100 pulses/revolution at the same price (around 2000 yen), so I used this. Since it has no click, when you actually use it, the frequency sometimes shifts during operation. Therefore, I quickly added an F_LOCK switch. |
| Waveform Monitor |
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Up until now, one receiver has received signals from each station and
monitored the air of the receiver's own transmitted radio waves, with a
separate receiver used to monitor the waveform using FFT or similar.
However, this required the tuning and mode of both units to be changed
every time the band was changed or shifted to another frequency, but this
new receiver has this function built in, so by receiving the main route,
the waveform monitor is always tracking, and no special operations are
required. The waveform below is a transmitted radio wave in the 3.5KHz
band. 'SDR' button  When
you press and turn it ON, the signal is always demodulated with a 5KHz
shift downwards, and the center = 5KHz point in the 10KHz span becomes the
receiving carrier point. In other words, 5KHz to the lower 5KHz = LSB
signal, and 5KHz to the upper 5KHz = USB signal are output to the waveform
monitor, and when SDR = OFF, the normal demodulated signal of the main
route is output to the monitor, so you can always monitor the received
signal / your own monitor signal. |
| LSB (2T) signal of SDR output | LSB (audio) signal from SDR output |
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| USB (audio) signal output from SDR | ISB (audio) signal output from SDR |
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| Normal output 2T signal SPAN=5KHz | Normal output audio signal SPAN=5KHz |
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| System integration function |
| All of these functions, except for the transceiver function, can be realized by connecting a general signal (TXB) from the transmitter to this receiver. TXB is 5V or more when transmitting, and 0V when receiving. |
| SP-MONITOR function |
This receiver also uses the air monitor, so if you
switch to transmit mode while receiving with the speaker, feedback will
occur if the speaker is active.  When
is OFF, the speaker amplifier is muted when the receiver switches to
transmit mode, and no audio will come out. However, there are times when
you may want to monitor the speaker while transmitting (to check the sound
quality of music or frequency deviation caused by feedback, etc.). In such
cases, turn the SP-MON switch ON. This can be done by moving the speaker
VR up and down, and is an easy operation. |
| EXTEND Function |
| In EXTEND=ON mode, the air monitor signal being transmitted is monitored in the Wid band regardless of whether the receiving filter is in Nar/Mid/Wid position, and when receiving returns to the original band. In EXTEND=OFF mode, the selected filter remains the same whether transmitting or receiving. |
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| (ATT+AGC) control function |
| ●When in transmission mode, an RF pickup signal is
generated for air monitoring and is sent to the receiver through an
attenuator, but the effect of an external ATT becomes weaker below a
certain value. Ideally, you would like to put an ATT inside the receiver,
but it is necessary to switch between receiving and transmitting. This
unit has a built-in 20dB ATT, so you can use this to force the ATT to ON
when transmitting and return it to ON when receiving. This is
automatically switched by the TXB signal. Alternatively, you can insert a
separate ATT other than 20dB for monitor use by the TXB signal. ●Another AGC control function is to discharge the AGC capacitor for several hundred milliseconds when switching from a transmitting state to a receiving state, so that reception can be resumed immediately at maximum sensitivity. |
| Transceiver Function |
 When TR
is ON, the band/frequency/mode status will be tracked with the previous
homemade transmitter. When it is OFF, the transmitter and receiver are
independent. However, this function requires connection to the transmitter
with a system cable. The previous control function using the TXB signal is
separate from this TR function. |
| Measurement results (sensitivity/distortion related) |
| This is a 2T signal from IF_455-OUT. When ANT terminal input = S9+50dB I set the maximum allowable input = S9+50dB, and I am satisfied because I was able to keep IM3 = -70dB or less. Even if an S9+60dB signal is received, the circuit will not saturate. The AGC range will go beyond the upper limit, but this is no problem in practical use. However, if you are using it as a measuring instrument, check with an input signal of S9+50dB or less. However, it is unlikely that you will receive a strong radio wave of S9+50dB or more. - Except for some people. |
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| This is a 2T signal from AUDIO-OUT. ANT terminal input = S9+50dB IM3 is below -70dB, but I think it's something to be proud of when compared to manufacturer products. |
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| This is a 2T signal from AUDIO-OUT. ANT terminal input = S9+30dB IM3 is kept below -70dB, and the strong signals from each station are only this strong at best. |
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| It is difficult to obtain stable data for sensitivity measurements because we do not have a shielded room. In reality, measurements are taken through a specified filter such as the JIS-A curve, so the actual values will probably be higher than these. |
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| The AGC characteristics of this unit are listed below. The AGC operating point is set to S5, and the AGC range is designed to be 80dB. |
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| Related Documents |
| Full circuit diagram by block | Parts list by block |
| Block Overview | Silk data by block |
| Production progress report | Overall wiring diagram |
| Check and Adjustment | operation manual |
| Changes・modifications |
| Block
Diagram 【overview】 As a receiver, I made an all-band PSN direct receiver (Neptune receiver), but each method has its advantages and disadvantages. The biggest feature of direct is that, for example, when receiving LSB, even if a signal above the receiving carrier point is received, it is not suppressed by AGC at all, so even if a jamming signal is received at the carrier point, the received signal will not become smaller. The disadvantage is that signals larger than the AGC operating point are at a constant level, but signals smaller than the operating point become proportionally smaller, and since the AGC range is small, it is necessary to turn the volume up and down in weak signal areas. However, the S/N ratio and fidelity are very good. This receiver is a double conversion type, and since the AGC range is wider than that of direct, it can receive signals of different strengths stably, but the advantages of direct become disadvantages and the disadvantages become advantages. 【Features】 １．An internal SG eliminates the need for an SG measuring device. Two levels of signals, S=9/9+40dB, can be applied to the ANT terminal. Any frequency can be set above or below the receiving frequency with a maximum resolution of 1Hz. ２．The ANT terminal input has a 0dB/20dB attenuator switch. ３．The 2nd-IF (455KHz) filter uses a Collins mechanical filter (2.5K/4K/10K), which is a bit expensive (8000 yen/each), but still suitable for a high-end receiver. ４．Equipped with an IF shift function, it can be adjusted up to ±999Hz with a maximum resolution of 1Hz, and it can shift the filter bandwidth up or down. For example, if you select a 2.5KHz filter and the scratchy sound of a station 3KHz below and the station 3KHz above (LSB signal) have a bandwidth of 3.4KH, which is 400Hz wider, there will be interference from the high-frequency rustling sound, but by using the IF shift, it is possible to avoid interference between the two signals. IF shift is only effective in narrow bands. This makes it a receiver with good selectivity. ５．This is a monitor signal that allows you to check the spectrum. In SDR=ON mode, the dedicated detector shifts the received frequency by 5KHz, allowing you to monitor up to ±5KHz at any time. In OFF mode, the normal detection signal for the selected band is output as a monitor. This is equivalent to having two built-in receivers. ６．The demodulated signal supports three modes: LSB, USB, and ISB. ７．The speaker VR and headphone VR are set up separately. ８．When the SP-monitor switch is OFF, the SP-AMP is muted during transmission to prevent feedback, and when it is ON, a switch is added so that the SP monitor can be used. ９．By setting up an EXT-SW, when it is ON, it will receive at the widest band (10KHz) in the system when transmitting, and will perform wideband air monitoring, and when it is OFF, if the filter you have set is 2.5KHz, it will perform air monitoring in that state. This is usually used in ON mode for your own emitted radio waves, but there are times when you want to use narrowband when performing hearing tests for up and down signals. １０．The RIT function has been added, and in ON mode the receiving and transmitting frequencies can be set independently. １１．Transceive function is possible when used in conjunction with a homemade transmitter (TX-Neptune/TX-Uranus). |
| Front panel image |
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| Back panel image |
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10.7MHz Cerafil |
RockwellCollins Mechafil (455KHz) |
| Ceramic filter 10.7MHz (30KHz range) |
455KHz (2.5KHz width) | 455KHz (4.0KHz width) | 455KHz (10KHz width) |
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| IF (455KHz) shift |
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When receiving LSB with a 455KHz filter =
2.5KHz and a wide 400Hz band LSB signal appears 3KHz below and 3KHz above,
if you receive in the 2.5KHz band, the lower station will have no problem
and there will still be room, but the 400Hz (whispering noise) from the
upper station will be heard and cause interference. In such a case, by
setting the carrier point (IF shift) = +400 to 500Hz, it is possible to
remove interference appropriately. (Pink band) |
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The displays I have used in my own machines up until now have been LCDs, but they are not TFT types, but surface-emitting types, so they have limited viewing angles and long access times, which made them less than ideal, but EL types do not require backlights, consume less current, have a free viewing angle, and are very bright and beautiful. This time, I decided to use the EL type. |
| Waveform Monitor Signal |
| 【When SDR=OFF mode】 The signal being listened to in the selected band is output as is. For example, the feeling of the received signal in the 4KHz band changes depending on whether the FFT frequency axis is displayed as linear or logarithmic, but I monitor it on a logarithmic axis in OFF mode. This is because I want to check the details around 40Hz to 120Hz, so I use this mode when checking the 2T signal radio waves of each station. Frequency axis = Linear (SPAN=5K) Frequency axis = Logarithmic (SPAN=5K) Frequency axis = Logarithmic (SPAN=5K)  【SDR=ON mode】 In this mode, a detection output signal dedicated to waveform monitoring is output. In this detection circuit, the signal is passed through a 10KHz band filter of 455KHz, shifted by 5KHz, and then USB detected and output. Therefore, to simultaneously monitor the upper and lower signals centered on the receiving carrier point, a maximum of ±5KHz is possible with the center set to 5KHz on the FFT. If you want to check a finer area, for example, if you want to see ±1KHz, you can set Start-F=4KHz, Stop-F=6KHz. I usually check at ±4KHz (Start-F=1KHz, Stop-F=9KHz). Since a detection signal of ±5KHz is always output, you can set it to any frequency band you want to check. In this mode, the frequency axis = linear mode is recommended. Start-F=0, Stop-F=10K (±5K) Start-F=1KHz, Stop-F=9KHz (±5K) Start-F=4KHz, Stop-F=6KHz (±1K)  Each signal above is a waveform of a received ISB signal, but when monitoring a single-sided signal, I usually check it with SPAN=4KHz (Start-F=1KHz, Stop-F=9KHz). Monitor waveform when receiving a USB signal ±4KHz (Start-F=1KHz, Stop-F=9KHz)  |
| February 19, 2015 |
Some of the specifications have been changed.
SP-MonitorSW = A switch that turns the speaker output ON/OFF during
transmission, and Monitor-Extend = A switch that switches the monitor
signal during transmission between normal band mode and wide band mode.
These two have been changed to seesaw switches, and S-VR and HP-VR have
been removed from the panel. The only VR knob on the panel is the meter
dimmer knob, and SP-VR and HP-VR are now controlled by rotary encoders. This receiver has a similar structure to the W receiver, and the weight of the DDS block to generate various carrier waves is large, so as we proceed with the verification, it is essential to implement the PWB of this block. First of all, the PWB artwork for the display/CPU/DDS/power supply unit has been completed and released. It is scheduled to arrive on February 25th. DDS Circuit Diagram Display circuit diagram Power supply circuit diagram  |
| March 2, 2015 The display, power supply, and DDS boards have arrived and are now fully assembled, so we will begin the process of connecting them to power. |
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Display
board unit (component side) The EL panel is fixed in place with 5mm spacers at two points on both sides above it. The only components to be mounted on the component side are the EL panel, keys and LEDs; everything else is mounted on the solder side. |
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Display board unit
(solder side) Attach the connector so that number ① matches the silk screen on the component side, and the digital tracker matches the shape of the silk screen on the component side. |
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Power supply board unit
Structurally, it has the same structure as the power supply unit of the TX-Neptune/Uranus. |
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The power supply unit is attached to a 3mm thick aluminum plate using an 8mm spacer. |
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Back panel completed I had one extra back panel board when I made the TX-Neotune/Uranus, and since I plan to use the same case this time, I used this board to complete the back panel. |
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Power supply heat sink attached to back panel The back panel plate is sandwiched between the aluminum plate of the power supply unit and the heat sink, completing the assembly. |
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DDS board unit This board is not assembled all at once, but first the components shown in the left photo are mounted. After all components are mounted, it is difficult to correct the soldering of the pins of the surface-mounted components, so check the current consumption of 3.3V and 5V in advance. 3.3V = 0.1A 5V = 0.13A |
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DDS board unit completed |
| March 6, 2015 |
Although I turned on the power, all signals other than
the VFO output (AD9854) came out without any problems as designed. That
said, there were various problems, but it was OK with just changing the
constants. However, I struggled with the VFO output for three days, but as
of today it is OK. I could list the causes and the process that led to
this, but I will refrain from doing so as it would be embarrassing. As a
result, no hardware or software changes were required, and I think you can
predict this by saying so far. I input a 10KHz reference clock and
confirmed that the nuclear power plant's 27MHz was locked. With this, I
was able to generate all the carriers required for the system (for VFO,
2ndMIX, 455PSN detection, SDR-MIX, SDR-PSN detection, and SG). |
| For all band VFO |
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| For 2nd-MIX |
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| For 455-DET (I/Q) |
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| For SDR-MIX |
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| For SDR-DET (I/Q) |
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| Initial screen 3.3V=0.1A 5V=0.1A  |
Normal screen 3.3V=0.4A 5V=0.28A(SG=OFF) 0.36A(SG=ON) This current value is normal.  |
| Optical Encoder Left: Iwatsu AIESEC (EC202A100A) 100 pulses/1 rotation Right: Copal (RES20D25-201) 25 pulses/1 rotation This time we plan to use Iwatsu AIESEC. |
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| March 12, 2015 Seven types of menu commands are provided to allow for flexibility. |
| This unit has a default of 1st IF = 10.7MHz, 2nd IF = 455KHz, and the filter band is not expressed as an absolute value of ○KHz, but can be switched between three types: Narrow, Medium, and Wide. The default values are Nar = 2.5KHz, Med = 4KHz, and Wide = 10KHz, but each can be set to any frequency and band. To access the menu commands, press the 'UP' key + 'DW' key to turn on the power. The menu number is selected with the encoder. |
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Menu-No=1 All parameters are set to default values with the initialization command, executed with the 'TR' key. |
Enter your callsign. |
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Menu-No=2 The optical encoder uses 100 pulses/revolution, so the software allows you to select the number of pulses per revolution from three options: 100/50/25. However, in IF shift/memory/menu mode, 25 pulses/revolution is intuitively easier to use, so this selection pulse is only applied to frequency tuning. Use the '→' and '←' keys to select 100/50/25, and execute with the 'TR' key. |
Default value: 100/1 rotation |
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Menu-No=3 Set the 1st IF frequency. Use the '→' and '←' keys to move to the desired digit and set with the encoder. Center frequency of the filter. |
Default value IF1=10.708MHz |
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Menu-No=4 Setting the second IF frequency. Use the '→' and '←' keys to move to the desired digit and set with the encoder. Center frequency of the filter. |
Default value IF2=455KHz |
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Menu-No=5 Set the filter band width (Narrow) and half the bandwidth. Default = Rocwell-Colins 455KHz (2.5KHz) |
Default value Nar=(2.5KHz)/2 =1.25KHz |
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Menu-No=6 Set the filter band (Medium) and 1/2 the bandwidth. Default = Rocwell-Colins 455KHz (4.0KHz) |
Default value Med=(4KHz)/2 =2.0KHz |
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Menu-No=7 Set the filter band (Wide) and half the frequency of the band width. Default = 455KHz (10KHz) Cerafilter. This band is used in ISB mode. |
Default value Wid=(10KHz)/2 =5.0KHz |
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After executing each menu command, the display on the left will appear and then the system will return to normal operation. | |
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Normal operation display |
| March 18, 2015 To all concerned parties, the first half of the process (generation of six types of carrier waves) can be developed into various shapes, so you can have fun with it. The frequencies of all stages can be freely set, so you can develop it with your own filters. The second half of the process will take some time. First of all, it is necessary to properly generate the necessary carriers and controllers. I will send the supplies from me to those concerned. |
This is the relevant document as of March 18th. The REF number of the DDS board is not included, so the REF number drawing and the constant print drawing are included in the DDS silk screen drawing file. Also, when the display board is assembled, the connector number (destination) on the solder side cannot be confirmed, so we have posted the silk screen drawing of the solder side of the display board. Circuit Diagram 0315 Parts list 0315 DDS Silk Drawing Display board solder side silk diagram 【Display unit】 1. There are unnecessary parts, please refer to the DISPLAY parts side. (X mark) 2. The rotary encoder has a specification of 100 pulses/revolution, and as a result an F-LOCK function is required, so a 2P connector was added (see the DISPLAY solder side). For the wiring between this 2P connector and the encoder, see the DISPLAY circuit diagram. 3. The order is to install them from the solder side first, and there are three types of components to be installed on the component side: tactile keys, display panel, and diodes. The rest are installed from the solder side first, and the digital transistors and connectors are silk-screened to show the shape they will have when installed from the solder side first.   4. The display panel and display board are connected using a 20-pin header.    【ＤＤＳ Unit】 1. The voltage supplied to the VCXO is +5V via two diodes. See the pattern cutting, support and circuit diagram. .2. Output signals other than I/Q signal output are isolated by transformers and are not referenced to GND. Terminate with 51 Ω at the tip of the 1.5D coaxial cable and check the signal at both ends.   For all connectors other than J1/J2/J5/J6, check with 51 Ω termination on both ends.  【caution】 CNP7 on the display board and CNP6 on the DDS board are connected with a connector, but this connector is the only one that is not processed one-to-one; check the signal names on each circuit diagram and process them to match. Therefore, only for this connector, clearly indicate the display side and DDS side, so as not to make a mistake when connecting. The others are processed one-to-one, so there is no need to worry about it. |
| March 22, 2015: Final panel image |
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April 1, 2015 We had intended to finalize the concept design on March 22nd, but after receiving various opinions and suggestions, it seems this is the final version. |
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| The demodulation of this unit is PSN demodulation, but the all-pass filter (AFPSN) is basically the same as that of a hybrid transmitter. The phase guarantee band of the AFPSN is determined by how much of the opposite band component is taken in based on the receiving carrier point of the filter. Since the IF-SFT also only has up to ±999Hz, a guarantee band of 4KHz is sufficient even considering the shape factor of the ceramic. But then there was ISB demodulation. In ISB demodulation, the carrier point is the center of the filter and ±5KHz is passed, so 1/2 of the filter band used is required as the phase guarantee band. There is no problem if it is only LSB/USB, but since SDR demodulation (PSN demodulation) only demodulates one side of the 10KHz band, a phase guarantee band of 3KHz to 4KHz (6 stages) is sufficient. The ideal configuration would be 8 stages for main demodulation and 6 stages for SDR demodulation. In the case of a receiver, we are concerned about the S/N ratio, so we want to use as few elements as possible. In practical use, I think 6 steps will be fine for the main demodulation, as there should be no radio waves greater than ±4KHz in ISB transmissions. For reference, I have posted the AFPSN used for SDR demodulation. |
Circuit Diagram |
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| April 7, 2015 To install the power supply unit, attach the device directly to the heat sink, open a 127mm x 64mm hole in the back panel, attach the power supply unit from the outside of the back panel, and secure it in place with screws in four places. |
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| April 11, 2015 IF Filter Block Rockwell Collins 455KHz mechanical filter + CFS455H |
| Filter characteristics, also known as
the heart of a receiver, determine how well it can eliminate signal
components outside the desired reception band. On the other hand, it is
difficult for DIYers to obtain filters with the desired characteristics at
a reasonable price in order to obtain high fidelity characteristics.
Recently, I searched for a Rocwell-Collins 455KHz mechanical filter, and
found that I wanted 2.5KHz, 4.0KHz, 8K or 10K for narrow band, medium
band, and wide band for SSB, but the filters available for purchase for
wide band use were 6KHz, and I could not find 8K/10K. 8K/10K is not
necessary for SSB, but since this unit has ISB function, 6KHz (±3K) is
narrow, so I would like at least 8K (±4K). However, you can't get what you
don't have, no matter how much you beg. Therefore, I will use Murata's
ceramic filter for wide band. Is the Collins mechanical filter affordable
(8800 yen/each)? To me, this is a high-end filter. In this block, three
types of filters are switched between, and an analog switch (74HC4052) is
used as the switching method. This switch has two circuits and four
contacts, so up to four types of filters can be switched between, and
because there are two circuits, it is logically possible to use one IC to
switch between the input and output sides. As with any circuit, issues
always arise when switching between several types of circuits, such as
isolation between circuits and isolation between input and output, and
because this unit switches filters, whether the guaranteed attenuation of
the filter characteristics can be obtained properly. For this reason,
there are a few poin 【Important Notice】 １. Murata's ceramic filter has a metal case, but the Collins mechanical filter is made of plastic, so the top and surrounding areas are wrapped in copper foil tape and grounded. Living state Copper foil wrapping   ２. Although there are two switches (74HC4052), one is used on the input side and one on the output side, for a total of two switches (input/output isolation). ３. The receiver on the SW output side is a low impedance receiver (isolation between filters). If you make it into a pattern, it doesn't require much thought. The characteristics results when switching this circuit are shown below. Circuit Diagram |
| Wideband mode Murata (CFS455H) SPAN=20KHz |
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| Mid-band mode Collins (4.0KHz) SPAN=10KHz |
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| Mid-band mode Collins (4.0KHz) SPAN=20KHz |
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| Narrowband mode Collins (2.5KHz) SPAN=10KHz |
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| Narrowband mode Collins (2.5KHz) SPAN=20KHz |
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