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Portable Radio Box
I built a self contained battery operated radio and intercom for our Taylorcraft BC12D using a 14 Amp-Hour sealed lead acid battery, and a MGL Avionics V-10 radio. My design goals were to keep it self-contained: one-box for portability, long battery life, good intercom, built-in volt meter, and relatively light weight.
The V-10 is available from Aircraft Spruce and costs ~$1100. It is very compact (approx 3x3x3 inches), lightweight (0.5 lb), and very low power consumption (250 mA in RX, 1.5A in TX). The V-10 has a built in intercom, and a built-in voltmeter. Here are the complete specs:
MGL Avionics V-10 COMM Radio Specifications
VHF air band transceiver based on ARM7 processor with digital audio CODEC and audio
signal processing in firmware. Conventional receiver with band input filter and high IP3 mixer.
Transmitter with digital modulator. Frequency reference high stability fully digital PLL (DPLL)
operating at 5GHZ.
Frequency range RX: 108.000-117.975MHZ (117.991MHZ Europe)
Frequency range TX: 118.000-136.975MHZ (136.991MHZ Europe)
Mode: AM (6K00A3E)
Output power TX: 6W at 13.0V (nominal specified power rating)
5.5W at 12.0V
4W at 10V (low voltage operation)
Max power 6W-7W at 13.8V and higher
Power output may vary +/-10% from nominal over the band
including spread between transceivers.
Power measured at the output connector into a 50 ohm
resistive load with unmodulated carrier.
Tuning steps: 1MHZ, 50KHZ, 25KHZ (8.33KHZ Europe)
Channels: 100 + 10 x 20 SL30/SL40 compatible frequency lists
Antenna impedance: 50 ohm
Receiver: Double conversion superheterodyne
1st IF 45MHZ 2nd IF 455KHZ
Transmitter: PDMOS output stage with class D digital modulator
Sensitivity: 2uV for 6dB S/N 1Khz 30% modulation
Spurious rejection: -70 dB
Transmission out of band: less than -60 dB
Audio output power: 0.5W into 8Ohm, 600Ohm compatible (up to 8 headsets)
Microphone: Electret with bias supplied by transceiver
Intercom: Two circuit with independent ambient noise suppression
a) Traditional VOX with selectable level and fading mute
b) MGL Avionics propriety digital VOGAD system
Audio subsystem: Fully digital with 18bit CODEC, 12Khz sampling rate.
Digital IIR filter technology throughout system.
COM: 2 x redundant RS232, Garmin SL30/SL40 compatible
MGL EFIS compatible, full remote control
1 x airtalk link for dual system operation
Since the V-10 has a very good intercom built-in, I wired a MIC and Headset jack for Pilot and Co-Pilot, and a common Push-To-Talk switch. I added a AUX 12VDC receptacle for a USB Jack to power GPS and/or iPad. Since our aircraft does not have an electrical system, I added a plug to attach a 12VDC battery maintainer in the hangar.
I fabricated the box out of .040 Alclad, and I laid the sealed battery on its side, on the box bottom, to lower the CG of the box. I used a soft AL, should have used 5052-H32 for a tighter bend radius.
Radio has at least a 30 mile transmit at 2000 feet, using the aircraft mounted Antenna.
Materials list to build the Portable Radio Box:
(1) 2'x4' .040 Aluminum Sheet 5051-H32
(1) 2' 3/4" x3/4"x1/16" Aluminum Angle for reinforcement
10' 1 conductor shielded 24AWG wire
10' 1 conductor 20AWG Tefzel wire
(3) microphone jacks
(2) headphone jacks
(1) Aux Power jack
(1) 2.5A circuit breaker
(1) SPST switch
(1) 12V, 14 AH Sealed Lead Acid Battery (approx 6"x6"x3")
(1) 12VDC, 2A solid state battery maintainer (trickle charger)
(1) MGL Avionics V-10 Comm Radio w/intercom
Fabrication work was pretty slow, as I cut everything with tin-snips and filed to shape. I used a 18" mini-brake for most of the bends, (not very accurate) and did some solid riveting, where I could have used pop-rivets. I estimate I had 20-30 hours in fab and rework…
Things that I would do in Version 2 would be to make a more accurate box using a temper aluminum, add a handle to carry outside the plane, and use "keyed" components to prevent spinning in the mounting holes. By making a "square" box, I would have space to add a transponder like the new Sandia Aerospace STX 165.
The 14AH battery would power both radio and transponder nicely. I estimate the battery will last 28 hours in receive mode (14AH / 0.5A = 28 hours). I flew Austin to Kansas City in one day, and it was still reading 12.5 volts. The iPad was down to 20% power when I landed in Kansas City. With this large of a battery, the weight of the Radio Box is 14lbs, at least 11 of which is the battery.
The V-10 is available from Aircraft Spruce and costs ~$1100. It is very compact (approx 3x3x3 inches), lightweight (0.5 lb), and very low power consumption (250 mA in RX, 1.5A in TX). The V-10 has a built in intercom, and a built-in voltmeter. Here are the complete specs:
MGL Avionics V-10 COMM Radio Specifications
VHF air band transceiver based on ARM7 processor with digital audio CODEC and audio
signal processing in firmware. Conventional receiver with band input filter and high IP3 mixer.
Transmitter with digital modulator. Frequency reference high stability fully digital PLL (DPLL)
operating at 5GHZ.
Frequency range RX: 108.000-117.975MHZ (117.991MHZ Europe)
Frequency range TX: 118.000-136.975MHZ (136.991MHZ Europe)
Mode: AM (6K00A3E)
Output power TX: 6W at 13.0V (nominal specified power rating)
5.5W at 12.0V
4W at 10V (low voltage operation)
Max power 6W-7W at 13.8V and higher
Power output may vary +/-10% from nominal over the band
including spread between transceivers.
Power measured at the output connector into a 50 ohm
resistive load with unmodulated carrier.
Tuning steps: 1MHZ, 50KHZ, 25KHZ (8.33KHZ Europe)
Channels: 100 + 10 x 20 SL30/SL40 compatible frequency lists
Antenna impedance: 50 ohm
Receiver: Double conversion superheterodyne
1st IF 45MHZ 2nd IF 455KHZ
Transmitter: PDMOS output stage with class D digital modulator
Sensitivity: 2uV for 6dB S/N 1Khz 30% modulation
Spurious rejection: -70 dB
Transmission out of band: less than -60 dB
Audio output power: 0.5W into 8Ohm, 600Ohm compatible (up to 8 headsets)
Microphone: Electret with bias supplied by transceiver
Intercom: Two circuit with independent ambient noise suppression
a) Traditional VOX with selectable level and fading mute
b) MGL Avionics propriety digital VOGAD system
Audio subsystem: Fully digital with 18bit CODEC, 12Khz sampling rate.
Digital IIR filter technology throughout system.
COM: 2 x redundant RS232, Garmin SL30/SL40 compatible
MGL EFIS compatible, full remote control
1 x airtalk link for dual system operation
Since the V-10 has a very good intercom built-in, I wired a MIC and Headset jack for Pilot and Co-Pilot, and a common Push-To-Talk switch. I added a AUX 12VDC receptacle for a USB Jack to power GPS and/or iPad. Since our aircraft does not have an electrical system, I added a plug to attach a 12VDC battery maintainer in the hangar.
I fabricated the box out of .040 Alclad, and I laid the sealed battery on its side, on the box bottom, to lower the CG of the box. I used a soft AL, should have used 5052-H32 for a tighter bend radius.
Radio has at least a 30 mile transmit at 2000 feet, using the aircraft mounted Antenna.
Materials list to build the Portable Radio Box:
(1) 2'x4' .040 Aluminum Sheet 5051-H32
(1) 2' 3/4" x3/4"x1/16" Aluminum Angle for reinforcement
10' 1 conductor shielded 24AWG wire
10' 1 conductor 20AWG Tefzel wire
(3) microphone jacks
(2) headphone jacks
(1) Aux Power jack
(1) 2.5A circuit breaker
(1) SPST switch
(1) 12V, 14 AH Sealed Lead Acid Battery (approx 6"x6"x3")
(1) 12VDC, 2A solid state battery maintainer (trickle charger)
(1) MGL Avionics V-10 Comm Radio w/intercom
Fabrication work was pretty slow, as I cut everything with tin-snips and filed to shape. I used a 18" mini-brake for most of the bends, (not very accurate) and did some solid riveting, where I could have used pop-rivets. I estimate I had 20-30 hours in fab and rework…
Things that I would do in Version 2 would be to make a more accurate box using a temper aluminum, add a handle to carry outside the plane, and use "keyed" components to prevent spinning in the mounting holes. By making a "square" box, I would have space to add a transponder like the new Sandia Aerospace STX 165.
The 14AH battery would power both radio and transponder nicely. I estimate the battery will last 28 hours in receive mode (14AH / 0.5A = 28 hours). I flew Austin to Kansas City in one day, and it was still reading 12.5 volts. The iPad was down to 20% power when I landed in Kansas City. With this large of a battery, the weight of the Radio Box is 14lbs, at least 11 of which is the battery.
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