The Full Review of the Yaesu FT-817 Transceiver
For the ARS Lab
Feeling a little tangled up with knotty technical questions? Many of our graphics have this portrait of a fellow electronics adventurer. Just click, and you're on your way to helpful background material.
Transmitter Tests
Power Output
With both a 12 volt and a13.8 volt power supply, our sample produced an output of 3.8 watts on 20 meters.
Power Requirements on Transmit
With both a 12 volt and 13.8 volt power supply, our FT-817 drew 1.91 amps on 20 meters.
Spectral Purity
FCC regulations require the spurious emissions from a 5 watt radio to be at least 40 dB below the carrier. For a radio running less than 5 watts, the regulations require the spurious emissions to be at least 30 dB below the carrier.
Our FT-817 easily met both requirements on 20 meters.
Here is the link to the 20 meter spectral purity graph for our sample.
Keying
The FT-817 had an adequate keying waveform, as shown on this oscilloscope trace.
Introduction to Receiver Tests
Many of our receiver test reports use bar charts that compare the unit being reviewed to a number of other HF transceivers. Please read this brief explanation of the purpose and layout of these charts.
Receiver Tests—When No External Signals are Present
Spurious Signals
In the nine HF bands, we counted 29 birdies.
Power Requirements on Receive
Our sample drew 356 mA on receive with both a 13.8 and 12.0 volt power supply.
Receiver Tests—When One External Signal is Present
Minimum Discernible Signal
On 20 meters we measured an MDS of -127 dBm with the preamp off, and -136 dBm with the preamp on. Please follow this link for comparisons with the MDS of other HF radios.
Phase Noise
We measured phase noise of -121 dBc/Hz at a spacing of 10 kHz from the carrier. Please follow this link for comparisons with the phase noise of other HF radios.
IF Rejection
Our sample's IF rejection was 96 dB with the preamp both off and on. Please follow this link for comparisons with the IF rejection of other HF radios.
Image Rejection
Our FT-817's image rejection was 86 dB with the preamp both off and on. Please follow this link for comparisons with the image rejection of other HF radios.
Receiver Tests—When Multiple Signals are Present
Selectivity
We measured the following 6 dB IF and AF responses for our sample:
Wide filter—2310 Hz
Narrow filter—580 Hz
You will find interesting information about the width and shape of the FT-817's IF and RF response in this AF spectrum analyzer graph.
Blocking Dynamic Range
Our sample had a blocking dynamic range of 104 dB with the preamp off and 113 with the preamp on. Please follow this link for comparisons with the blocking dynamic range of other HF radios.
In-band IMD
The FT-817 had a poor response to the In-Band IMD test. Here is the link to the FT-817's AF spectrum analyzer graph.
Two Tone Intermodulation Distortion Tests
Third Order IMD Dynamic Range: 84 dB with the preamp off, 83 dB with the preamp on. Please follow this link for comparisons with the Third Order Dynamic Range of other HF radios.
Third Order IMD Intercept Point: -1.5 dBm with the preamp off, -12.5 with the preamp on. Please follow this link for comparisons with the Third Order IMD Intercept Point of other HF radios.
Second Order IMD Dynamic Range: 107 dB with the preamp off, 106 dB with the preamp on. Please follow this link for comparisons with the Second Order IMD Dynamic Range of other HF radios.
Second Order IMD Intercept Point: 87 dBm with the preamp off, 76 dBm with the preamp on. Please follow this link for comparisons with the Second Order IMD Intercept Point of other HF radios.
The Receiver Factor
The FT-817 received a score of -20.9 dBm with the preamp off and -22.9 dBm with the preamp on. Please follow this link for comparisons with the receiver factor scores of other HF radios.
********
Here are some important links:
The lab's goals and equipment.