The Muntjac SDR - Revision history

G4EWJ: /* Mixing Options */

2026-04-29T12:19:30Z

Mixing Options

2026-04-29T12:15:29Z

Programming the Microcontroller on the Muntjac

2026-04-29T12:14:32Z

LEDs

2026-04-28T14:32:04Z

2026-04-28T14:30:54Z

2026-04-28T13:02:07Z

Using the Third Harmonic of the Low Band for DATV on 23cm

2026-04-28T12:53:12Z

Using the Third Harmonic of the Low Band for DATV on 23cm

2026-04-28T12:36:02Z

Muntjac I/O Connectors

2026-04-28T12:35:22Z

Muntjac I/O Connectors

2026-04-28T12:24:24Z

@@ Line 236: / Line 236: @@
 Any mixer output MUST be bandpass filtered for the required output frequency. This is particularly important for 23cm, where on 1270MHz for example, the required third harmonic of the low band carrier may be only 58MHz away from the target frequency.
-The low band carrier power is set at 26, which is nominally +11dBm. If a passive mixer is used, a Level7 (7dBm local oscillator) mixer is recommended. A suitable mixer is a MiniCircuits ADE-30+ (NOT the ADE-30W+, although that may be more suitable depending on your requirements). https://www.minicircuits.com/pdfs/ADE-30+.pdf
+The low band carrier power is set at 26, which is nominally +11dBm. If a passive mixer is used, a Level7 (7dBm local oscillator) mixer is recommended. A suitable mixer is a MiniCircuits ADE-30+ (NOT the ADE-30W+, although that may be more suitable depending on your requirements). Mixers in the ADE series can look the same, but have different footprints, so do check carefully that any other mixer is compartible with the pcb. https://www.minicircuits.com/pdfs/ADE-30+.pdf
 The high and low band outputs are connected to the RF and LO ports of the mixer, which are specced at 200-3000MHz and the output is taken from the IF port, which is specced at 0-1000MHz. The output is likely to be in the range of the tens of microwatts. The 23cm band is outside the IF range, but still produces a usable output.

@@ Line 201: / Line 201: @@
 . Hold down the BT button (the one nearest the SMA sockets) on the Muntjac while connecting it to your PC using its USB port. The Pico Muntjac appears as a USB disk drive on your PC.
-. Copy the .uf2 file onto the USB drive. The Muntjac will recognise the file and immediately update its firmware, reboot and the PC should recognise a new USB COM device. The main LED on the Muntjac will blink in morse as it reboots. This will be 'HI' for firmware version 1v0b and "MJ" plus the last letter of the firmware version for later versions of the firmware.
+. Copy the .uf2 file onto the USB drive. The Muntjac will recognise the file and immediately update its firmware, reboot and the PC should recognise a new USB COM device. The main LED on the Muntjac will blink in morse as it reboots. This will be 'HI' for firmware version 1v0b and "MJ" plus the last letter of the firmware version for later versions of the firmware. After a few seconds for initialisation, the main LED will light steady.
 . Disconnect the Muntjac from the PC and connect it to the Portsdown.  Make sure that the Muntjac is selected as the Output Device and then Select M2, Info.  The Muntjac firmware version will be displayed along with the Muntjac Flash ID.

@@ Line 124: / Line 124: @@
 There is a main LED near the buttons and an LED near each SMA socket.
-The main LED blinks 'HI' in morse (.... ..) at power up. This is for software version 1v0b. Later versions will blink 'MJ' and the last letter of the software version.
+The main LED blinks 'HI' in morse (.... ..) at power up. This is for software version 1v0b. Later versions will blink 'MJ' and the last letter of the software version. After a few seconds for initialisation, the main LED will light steady.
 The LED near each SMA socket is normally off and lights when that band (low or high) is in use.

@@ Line 220: / Line 220: @@
 [[File:MJputty1.png|400px]]
 ===Updating the Muntjac Firmware Using a Portsdown===
-If the Muntjac is built into a Portdown system, it may not be possible to access the USB socket on the Muntjac. A procedure is being developed to help with this.
+If the Muntjac is built into a Portsdown system, it may not be possible to access its USB socket. A procedure is being developed to help with this.
 ===Mixing Options===

← Older revision		Revision as of 14:30, 28 April 2026
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	[[File:MJputty1.png\|400px]]		[[File:MJputty1.png\|400px]]
		+
		+	===Updating the Muntjac Firmware Using a Portsdown===
		+
		+	If the Muntjac is built into a Portdown system, it may not be possible to access the USB socket on the Muntjac. A procedure is being developed to help with this.

	===Mixing Options===		===Mixing Options===

@@ Line 268: / Line 268: @@
 [[File:Third Harmonic.jpg|400px]]
-''The fundamental at 418.3 MHz on the left with the 3rd hamonic on 1255 MHz on the right''
 ===Command Line Operation===

@@ Line 265: / Line 265: @@
 ===Using the Third Harmonic of the Low Band for DATV on 23cm===
-Details will appear here.
+The third hamonic of 418.333 MHz can be used to transmit on 1255 MHz.  The third harmonic is about 20 dB down on the fundamental, so good filtering is required.  More details will appear here.
 ===Command Line Operation===

← Older revision		Revision as of 12:36, 28 April 2026
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−	===Muntjac I/O Connectors===	+	===Muntjac Input/Output Connectors===

	The 40 pin J101 position will allow the Muntjac to connect directly to a Raspberry Pi. This will provide power and also an SPI link, which will allow higher data rates for future development. It is recommended that no connector is fitted here until the required orientation and gender is known.		The 40 pin J101 position will allow the Muntjac to connect directly to a Raspberry Pi. This will provide power and also an SPI link, which will allow higher data rates for future development. It is recommended that no connector is fitted here until the required orientation and gender is known.

@@ Line 288: / Line 288: @@
 The 12 pin J4 position is for general I/O.
-All Muntjac I/O pins are connected directly to the RP2040 microcontroller, so caution should be exercised regarding static and voltage levels. 3.3v is the nominal voltage level.
+.3v power is available on J3 and J4. The available current is yet to be determined.
 There are no pins on J3 or J4 that connect to J101.

← Older revision		Revision as of 12:24, 28 April 2026
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	[[File:Image 2026-04-28 12-58-03.png\|1080px]]		[[File:Image 2026-04-28 12-58-03.png\|1080px]]
		+
		+
		+	===Muntjac I/O Connectors===
		+
		+	The 40 pin J101 position will allow the Muntjac to connect directly to a Raspberry Pi. This will provide power and also an SPI link, which will allow higher data rates for future development. It is recommended that no connector is fitted here until the required orientation and gender is known.
		+
		+	The 8 pin J3 position can be used for general I/O or to allow future developments to connect a WIZnet Ethernet module for applications that do not require a Raspberry Pi.
		+
		+	The 12 pin J4 position is for general I/O.
		+
		+	All Muntjac I/O pins are connected directly to the RP2040 microcontroller, so caution should be exercised regarding static and voltage levels. 3.3v is the nominal voltage level.
		+
		+	There are no pins on J3 or J4 that connect to J101.

	===Problems===		===Problems===