Kenwood TH-D74 Compliance Test
Compliance testing to ascertain if this radio meets ITU guidelines for spurious emissions.
Kenwood TH-D74 Final Grade: PASS
The Kenwood TH-D74 amateur radio sample we tested was fully compliant with ITU guidelines on spurious emissions, which is unusual for a tri-band radio.
It is important to note that this was a single-sample test and that it is possible other samples could vary in performance.
Discuss this radio on our forums. https://forums.advancedamateur.ca/t/kenwood-th-d74
Power Output Testing
Power output was measured using a Surecom SW-33 Plus into a dummy load. The radio was set to maximum power. The ITU guidelines for spurious emissions require measurements of "the power (W) supplied to the antenna transmission line". That requirement makes this separate power measurement necessary, as it is incorrect to measure relative to the fundamental (f0). All numbers have been rounded.
2M
146.520 Mhz
4.4 watts
70cm
446.000 Mhz
4.5 watts
1.25M
223.500 Mhz
5.3 watts
Spurious Emissions Testing
Spurious emissions were measured using a Tiny SA Ultra. The radio was set to maximum power and was connected to the TinySA through an attenuator. It is important to understand that the graphs below are using a decibel scale, not a linear scale. If a spurious emission spike appears to be almost as tall as the fundamental, that does not mean it is emitting almost as much power. Refer to the raw data shown.
VHF 2m Band Test Results: PASS
Raw Data 2m
All numbers have been roundedPower at Antenna: 36.4 dBm (4.4 watts)
Fundamental (f0): 35.8 dBm (3.8 watts)
The Kenwood TH-D74 sample that we tested displayed no noticeable harmonic emissions above the 2m band fundamental. All spurious emissions were at least 57 dB down from the power at the antenna, which is fully compliant with ITU guidelines.
UHF 70cm Band Test Results: PASS
Raw Data 70cm
All numbers have been roundedPower at Antenna: 36.5 dBm (4.5 watts)
Fundamental (f0): 34.9 dBm (3.1 watts)
The Kenwood TH-D74 sample that we tested displayed no significant spurious emissions above the 70 cm band fundamental in our testing. All spurious emissions were at least 57.2 dB down from the power at the antenna, which is fully compliant with ITU guidelines.
220 1.25M Band Test Results: PASS
Raw Data 1.25M
All numbers have been roundedPower at Antenna: 37.2 dBm (5.3 watts)
Fundamental (f0): 36.2 dBm (4.1 watts)
The Kenwood TH-D74 sample that we tested displayed no significant spurious emissions above the 1.25 m band fundamental in our testing. All spurious emissions were at least 57.4 dB down from the power at the antenna, which is fully compliant with ITU guidelines.
Comments
The Kenwood TH-D74's performance in these tests was noteworthy given its tri-band capabilities. Most tri-band radios emit spurious emissions on at least one of their bands. The TH-D74 was totally clean on all of its bands.
Many thanks to Horace VA7XHB for the use of his radio for testing.
~Reg Natarajan VA7ZEB / HJ1ZEB, August 31, 2024
Discuss this radio on our forums. https://forums.advancedamateur.ca/t/kenwood-th-d74