Product Review
Edited by Rick Lindquist, N1RL• Senior Assistant Technical Editor
Alinco DX-77T MF/HF Transceiver
Reviewed by Joe Bottiglieri, AA1GW
ARRL Technical Information Service
Coordinator
With improvements in propagation on
the HF bands over the last few months, stories of wide-open bands and easy DX are
rapidly spreading. If you’re a newcomer
looking to join the fun without cleaning out
the bank account, upgrading from “hollow
state,” or are just considering a new or second HF radio for your shack (or at that second QTH in the woods), the Alinco DX-77T
may be just the ticket. Here’s an economical
HF box in the $1000 price category that
won’t take up a lot of space on the operating
desk but still has plenty to offer.
Already known for its VHF and UHF
products, Alinco entered the HF market in
1995 with the release of the DX-70T. This
compact HF-plus-6 meters transceiver
proved to be a popular choice for mobile,
home station, and portable operation. A subsequent model, the DX-70TH, offered 100
W on 6 meters. With the introduction of the
DX-77T, Alinco now adds a somewhat
larger HF-only transceiver to their lineup.
What’s it Got?
The DX-77T is a 100 W output SSB,
CW, FM and 40 W AM transceiver that
covers 160 through 10 meters and includes
0.5 to 30 MHz general-coverage receiving
capability. It features dual VFOs, split operation, 100 memory channels, band stacking registers, a speech processor, IF shift,
multiple scan options, computer controllability, and a front-facing speaker. But wait!
A built-in CW keyer, 500Hz CW filter, and
menu selectable CTCSS encode for 10meter FM repeater operation also are all
standard features (in the US version). In
comparison, setting CTCSS tones in the
DX-70T required setting DIP switches, and
the earlier radio had no CW keyer.
While Alinco has managed to pack in
some very nice capabilities, they’ve also
kept the front panel surprisingly simple and
functional, with just a few large buttons and
knobs and bold, bright labels. Physically
larger than the current crop of subcompact
base/mobile type HF transceivers on the
market the DX-77T is a more convenient
size for desktop or portable operation.
Many users will welcome the generous dimensions. You could almost operate this
radio with oven mitts on!
Although it’s on the small side, the busy
LCD display offers good contrast and easy
readability. Backlighting is adjustable to
52 June 1998
five brightness levels (or off altogether). In
addition to the operating frequency, the window displays icons for mode, noise blanker,
AGC slow or fast (AGC cannot be disabled),
memory number, VFO A and B, split, narrow CW filter, CTCSS tone state, RIT offset
and low power. A four-section readout indicates the state of the two-stage attenuator/
normal/or 10-dB preamplifier RF gain level.
An LCD bargraph-type S meter indicates
relative power output on transmit.
Up Front
The front panel sports 14 buttons and
four knobs, with one concentric control.
The all-mode
trols are huge by today’s standards,
almost
shift knobs are a concentric pair, mounted
in the upper right corner. Center detents in
their travel indicate zero settings, with RIT
adjustable to approximately ±1.0 kHz. The
RIT function is always available—there’s
no way to clear it or turn it off. Some users
might find this a disadvantage.
SQUELCH and AF GAIN con-
5
/8 inch in diameter! The RIT and IF
BOTTOM LINE
A $1000-class desktop radio, the
DX-77T is easy to use and a moderately good performer with some nice
features you wouldn’t typically expect
at this price.
The large main tuning knob spins
smoothly (some users thought a little too
easily, however), is lightly weighted, and
includes a finger dimple. The tuning rate is
fixed at 2 kHz per knob revolution for
SSB/CW and 10 kHz per revolution for FM/
DIAL LOCK button is located to the
AM. A
lower right of the main knob. For large
changes in frequency, the
used in conjunction with the front panel
and DOWN buttons allows stepping through
the band registers and memory channels, or
frequency changes in 1 MHz or 100 kHz
steps. Smaller mode-related step sizes are
selectable in the set mode. A small frontfacing speaker sends the audio in the right
direction, a very nice arrangement. A jack
for an 8-pin microphone connection and
3.5-mm jacks for an external key or
paddles, an external speaker, and headphones are mounted along the bottom of
the speaker grille.
yellow push button located in the top left
corner. Side-by-side green and red LEDs
just to the left of the display window indicate transmit or receive, with the green
LED showing received signal, and the red
showing transmit, with increasing brightness on ALC peaks. Four large, black,
rectangular buttons form a vertical row to
the left of the main tuning knob. Side-byside white and light green legends above
each button indicate their primary and sec-
POWER ON/OFF switch is a large
The
SELECT button
UP
Table 1
Alinco DX-77T, serial number T000528
Manufacturer’s Claimed Specifications Measured in the ARRL Lab
Frequency coverage: Receive, 0.5 to 30 MHz; As specified.
transmit, 1.8-2, 3.5-4, 7-7.3, 10.1-10.15,
14-14.35, 18.068-18.168, 21-21.45,
24.89-24.99; 28-29.7 MHz.
Size (height, width, depth): 3.9×9.7×10.5 inches; weight, 8.4 pounds.
Power requirement: Receive, 1.1 A (max); transmit, 20 A (max). Receive, 0.8 A; transmit, 16 A. Tested at 13.8 V.
Modes of operation: SSB, CW, AM, FM, WBFM. As specified.
Receiver Receiver Dynamic Testing
SSB/CW sensitivity, bandwidth not specified: 0.5-1.8 MHz, –107 dBm; Minimum discernible signal (noise floor), 500 Hz filter:
1.8-30 MHz, –119 dBm.
AM sensitivity, 10 dB S/N: 0.5-1.8 MHz, 10 µV; 1.8-30 MHz, 2 µV. 10 dB (S+N)/N, 1-kHz tone, 30fi modulation:
FM sensitivity, 12 dB SINAD: 0.5 µV. For 12 dB SINAD:
Blocking dynamic range: Not specified. Blocking dynamic range, 500 Hz filter:
Two-tone, third-order IMD dynamic range: Not specified. Two-tone, third-order IMD dynamic range, 500 Hz filter:
Third-order intercept: Not specified.
Second-order intercept: Not specified. Preamp off, +53 dBm; preamp on, +51.5 dBm.
FM adjacent channel rejection: Not specified. 29 MHz: 60 dB, at 20 kHz channel spacing, preamp on.
FM two-tone, third-order IMD dynamic range: Not specified. 29 MHz: 63 dB* at 20 kHz channel spacing, preamp on.
S-meter sensitivity: Not specified. S9 signal at 14.2 MHz: preamp off, 36 µV; preamp on, 16 µV.
Squelch sensitivity: Not specified. At threshold, preamp on: SSB, 14 MHz, 1.0 µV; FM, 29 MHz, 0.1 µV.
Receiver audio output: 2 W at 10% THD into 8 Ω. 2.1 W at 10% THD into 8 Ω.
IF/audio response: Not specified. Range at –6dB points, (bandwidth):
Spurious and image rejection: 70 dB. First IF rejection, 114 dB; image rejection, 104 dB.
Transmitter Transmitter Dynamic Testing
Power output: SSB, CW, FM: 100 W high, ≈10 W low; CW, SSB, FM, typically 106 W high,
AM, 40 W high, ≈4 W low. 11 W low; AM, typically 42 W high, 6 W low.
Spurious-signal and harmonic suppression: 50 dB (45 dB on 30 M). 52 dB. Meets FCC requirements for spectral purity for equipment in its
SSB carrier suppression: 40 dB. As specified.
Undesired sideband suppression: 50 dB. As specified. >60 dB.
Third-order intermodulation distortion (IMD) products: Not specified. See Figure 1.
CW keyer speed range: Not specified. 6 to 49 WPM.
CW keying characteristics: Not specified. See Figure 2.
Transmit-receive turn-around time (PTT release S9 signal, 19 ms.
to 50 % audio output): Not specified.
Receive-transmit turn-around time (tx delay): Not specified. SSB, 20 ms; FM, 8 ms. Unit is suitable for use on AMTOR.
Composite transmitted noise: Not specified. See Figure 3.
Note: Unless otherwise noted, all dynamic range measurements are taken at the ARRL Lab standard spacing of 20 kHz
∗Measurement was noise-limited at the value indicated.
†
Third-order intercept was determined using S5 reference.
1.0 MHz –127 dBm –129 dBm
3.5 MHz –132 dBm –140 dBm
14 MHz –130 dBm –136 dBm
1.0 MHz 3.2 µV 1.9 µV
3.8 MHz 1.4 µV 0.6 µV
29 MHz 0.7 µV 0.2 µV
3.5 MHz 109 dB* 110 dB*
14 MHz 111 dB* 112 dB*
3.5 MHz 92 dB* 93 dB*
14 MHz 94 dB* 95 dB*
3.5 MHz +12.6 dBm +4.5 dBm
14 MHz +17.3 dBm +9.5 dBm
CW-N (500 Hz filter): 525-1027 Hz (500 Hz);
CW-W: 150- 2288 Hz (2138 Hz);
USB-W: 216-2977 Hz (2761 Hz);
LSB-W: 186-2834 Hz (2648 Hz);
AM: 146-2894 Hz (2748 Hz).
power output class and frequency range.
Preamp off Preamp on
Preamp off Preamp on
Preamp off Preamp on
Preamp off Preamp on
Preamp off Preamp on
Preamp off Preamp on
†
ondary functions. The top button in this row
serves as a function button, allowing access to the secondary functions and the set
mode. The lower three buttons control various memory, VFO and scan features.
There’s a second set of six buttons in two
horizontal rows to the right of the main
tuning knob. The top row contains single
function buttons for
TUNE (for use with an external automatic
SELECT, MODE, and
tuner). The second row are dual function
buttons:
CW filter,
RF/FILTER for RF gain level and
NB/AGC for noise blanker and
automatic gain control fast or slow and
H/L/TONE for power output level and
CTCSS tone. All ten buttons also provide
access to set mode controls, including the
speech processor, display brightness, automatic LSB/USB selection, transmit inhibit,
the step size of the
UP/DOWN buttons, and
several additional settings related to CW
keyer and scan operations. A one page
“Controls Quick Reference” table in the
manual gives a description of the functions
performed by each of these ten buttons in
their primary, secondary and set mode applications. New users will definitely want
to photocopy this chart and keep it handy.
The only part about using this radio that
can be confusing—at least at first—is that
June 1998 53
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