Specifications

From March 2008 QST © ARRL
Receiver Receiver Dynamic Testing
FM two-tone, third-order IMD dynamic range: 20 kHz offset, preamp on:
Not specified 29 MHz, 77 dB
†
; 52 MHz, 78 dB;
10 MHz offset: 52 MHz, 85 dB.
S-meter sensitivity: Not specified. S9 signal at 14.2 MHz: preamp off,
110 µV; preamp 1, 31 µV;
preamp 2, 7.1 µV; 50 MHz,
preamp off, 136 µV; preamp 1,
38 µV; preamp 2, 6.7 µV.
Squelch sensitivity: SSB, 0.1-1.8, 50-54 MHz, At threshold, preamp on: SSB, 14 MHz,
2.0 µV; FM, 28-30, 50-54 MHz, 1.0 µV. 0.55 µV; FM, 29 MHz, 0.51 µV;
52 MHz, 0.44 µV.
Audio output power: 2.5 W into 4 Ω at 3.1 W at 0.5% THD into 4 Ω (max vol).
10% THD.
IF/audio response: Not specified. Range at –6 dB points, (bandwidth):
CW (500 Hz): 449-948 Hz (499 Hz),
‡
Equivalent Rectangular BW: 493 Hz;
USB: 144-1707 Hz (1563 Hz);
LSB: 146-1742 Hz (1596 Hz);
AM: 114-1826 Hz (1712 Hz).
Spurious and image rejection: HF, 70 dB; First IF rejection, 14 MHz, 84 dB;
50 MHz, 60 dB. 50 MHz, 62 dB; image rejection,
14 MHz, 118 dB; 50 MHz, 71 dB.
Transmitter Transmitter Dynamic Testing
Power output: HF & 50 MHz: SSB, CW, FM, HF: CW, SSB, FM, typically 108 W high,
100 W (high); AM, 25 W (carrier) 4 W low; AM, typ. 42 W high, 3 W low;
50 MHz: CW, SSB, FM, typ 99 W high,
4 W low; AM, typ. 26 W high, 2 W low.
Spurious and harmonic suppression: HF, 62 dB; VHF, 68 dB.
HF, >60 dB; VHF, 65 dB. Meets FCC requirements.
SSB carrier suppression: >60 dB. HF, 61 dB; VHF, 65 dB.
Undesired sideband suppression: >60 dB. HF, 65 dB; VHF, 68 dB.
Third-order intermodulation distortion (IMD) 3rd/5th/7th/9th order (worst case band):
products: –31 dB PEP at 100 W HF, –35/–40/–53/–56 dB PEP;
VHF, –34/–42/–52/–59 dB PEP;
CW keyer speed range: Not specified. 4 to 56 WPM.
CW keying characteristics: Not specified. See Figures 1 and 2.
Transmit-receive turnaround time (PTT release S9 signal, 25 ms.
to 50% audio output): Not specified. Unit is suitable for use on AMTOR.
Receive-transmit turnaround time (tx delay): SSB, 39 ms; FM, 36 ms.
Not specified.
Composite transmitted noise: Not specified. See Figure 3.
Size (height, width, depth): 4.5 × 14.4 × 12.4 inches; weight, 21.6 pounds
(not including power supply or accessories).
Price: Price: FT-950, $1500; DMU-2000 data management unit, $1000; µ-Tune kit A (160),
B (80/40) or C (30/20 meters), $500 each.
*Initial Lab testing revealed lower than expected IMD dynamic range test results. Subsequent
testing of two additional FT-950s indicated that our particular unit was defective. The Noise Floor,
Blocking Gain Compression and Two-Tone IMD Testing results shown here are from another
off-the-shelf FT-950, s/n 7L040087.
**When preamp 2 is switched in, the default roofing filter becomes 15 kHz. It is 3 kHz with
preamp off or preamp 1. Measurements were made with default settings.
***ARRL Product Review testing now includes Two-Tone IMD results at several signal levels.
Two-Tone, 3rd-Order Dynamic Range figures comparable to previous reviews are shown
on the first line in each group. The “IP3” column is the calculated Third-Order Intercept Point.
Second-order intercept points were determined using –97 dBm reference.
†
Measurement was noise-limited at the value indicated.
‡
Varies with pitch control setting.
Figure 1 — CW keying waveform for
the Yaesu FT-950 showing the first two
dits in full-break-in (QSK) mode using
external keying. Equivalent keying speed
is 60 WPM. The upper trace is the actual
key closure; the lower trace is the RF
envelope. (Note that the first key closure
starts at the left edge of the figure.)
Horizontal divisions are 10 ms. The
transceiver was being operated at 100 W
output at 14.2 MHz.
The 128 page FT-950 Operating Manual
is well illustrated and does a good job of
explaining the radio’s features and operation.
There’s a lot to this radio, and it’s worth spend-
ing some time going through the manual and
trying all of the features and settings. Yaesu
offers a PDF version of the manual on the
00.010.020.030.040.050.060.070.08
QS0803-PR01
QS0803-PR02
1401514017 1401914021 1402314025
-100
-80
-60
-40
-20
0
QS0803-PR0
3
-180
-160
-140
-120
-100
-80
-60
-40
-20
0
10
6
10
5
10
2
10
3
10
4
Figure 3 — Worst-case spectral display of
the Yaesu FT-950 transmitter output during
composite-noise testing. For the red
trace, power output is 100 W at 14.2 MHz.
The carrier, off the left edge of the plot,
is not shown. This plot shows composite
transmitted noise 100 Hz to 1 MHz from
the carrier.
Figure 2 — Worst-case spectral display
of the Yaesu FT-950 transmitter during
keying sideband testing. Equivalent
keying speed is 60 WPM using external
keying. Spectrum analyzer resolution
bandwidth is 10 Hz, and the sweep time
is 30 seconds. The transmitter was being
operated at 100 W PEP output at 14.2 MHz.
Table 1
Yaesu FT-950, serial number 7K030158
linear amplifier. To speed things along, Yaesu
offers an optional cable with the 10-pin plug
on one end and bare wires on the other, ready
to accept whatever plugs your amplifier
requires. Another optional cable allows plug-
and-play operation with Yaesu’s VL-1000
“Quadra” solid-state amplifier.