Product Review and Short Takes from QST Magazine
April 2010
Product Reviews:
Alinco DJ-G7T Triband Handheld Transceiver
Green Heron Engineering GH Everyware Wireless Cable
International Radio Roofing Filter for the IC-756PROIII
Short Takes:
LDG Z-11Pro Automatic Antenna Tuner
Copyright © 2010 by the American Radio Relay League Inc. All rights reserved.
PRODUCT REVIEW
2 M
70 cm
23 cm
*
Measurement noise limited
at value shown.
Key:
**
Off Scale
pr046
250
50
T-R
Tx-Rx Turnaround Time (ms)
290**
100 800
Snd
490
Audio Output (mW)
60 110
Img
Image Rejection (dB)
105*
100*95*
60
110
IF
107*
104*
IF Rejection (dB)
103*
ChRej
50
90
51
48**
Adjacent Channel Rejection (dB)
57
40
70
I
3
Rx
53*51*
Receiver 3rd-Order Dynamic Range (20 kHz, dB)
57*
I
3
Rx
7362
9060
Receiver 3rd-Order Dynamic Range (10 MHz, dB)
69
0.25
0.1
SINAD
0.17
0.19
Receiver Sensitivity (12dB SINAD, µV)
0.17
Alinco DJ-G7T Triband
Handheld Transceiver
Reviewed by Bob Allison, WB1GCM
ARRL Test Engineer
There are plenty of dual band handheld
transceivers on the market, but this transceiver includes 23 cm (1240 MHz) band operation at 1 W, along with the more familiar
2 meter and 70 cm bands at 5 W output. This
23 cm band capability was enough to make
me curious and sign up to perform the review.
I had never worked this part of the spectrum
before, but a quick look at the ARRL
Repeater Directory suggests heavy usage of
the 23 cm band in some areas. I had
never worked FM satellites before
2 meter and 70 cm capability can work
the FM satellites, but I was curious
either. Any handheld radio with
about the DJ-G7T’s full duplex capabil-
ity. Once again I was reminded of the
vast scope of ham radio in which there is
always room for a new adventure.
Out of the Box
When I opened the box, I was pleased to
see a drop-in battery charger included, rather
than the usual wall charger. After about three
hours, the DJ-G7T’s 1200 mAh lithium ion
(Li-ion) battery was fully charged and ready
for testing.
As with any other complicated modern
will save a lot of time. Without reading the
manual, it took several minutes for me to
transceiver, thoroughly reading the manual
simply find the POWER switch, an inconspicu-
ous button mounted flush to the left side of
The polycarbonate body felt comfortable
the case.
in my hand. The overall size and weight would
not be a burden even with extended use. The
chassis is die-cast metal but not the case,
wouldn’t survive the steam-roller test, the DJ-
so take some care in handling. Although it
G7T will survive a splash in a pond, or a severe
weather event. It’s rated to withstand submer-
The POWER button must be held down
for one second. My large fingers had diffi-
culty keeping enough pressure on the flush
sion in 3 feet of water for 30 minutes.
mounted button for the required time. Alinco
indicates that the high button pressure is in-
tentional to prevent accidental turn-on. The
rest of the 19 buttons were manageable.
Mark J. Wilson, K1RO
The 11⁄2 × 3⁄4 inch green, backlit LCD is
easy to read and has several display options.
Display icons are intuitive and large enough
to see. The keypad is straightforward once
you learn the functions. The MAIN button
toggles among the three ham bands, while
the SUB button toggles through several bands
from 530 kHz through 1300 MHz.
The DJ-G7T sports a 61⁄4 inch flexible
antenna with an SMA connector. Next to the
antenna is a jack for an optional speaker/mic
with a heavy duty screw down cover and gasket to keep out the elements when not in use.
Most prominent are two sets of concentric
knobs (one set for each of the two receivers).
The inner knobs are used mainly for tuning
the main and sub receivers, while the outer
knobs act as VOLUME controls. The default
setting has the main receiver on the left
and the sub receiver on the right, but this
arrangement can be reversed via a menu
setting. Along the left side of the case are
the POWER switch, a MONITOR button
(momentarily opens the squelch) and
the PTT switch. The right side of the
case features a jack for external 4.5
to 16 V dc input.
The DJ-G7T comes with a wrist
strap and belt hook. The belt hook
is a cloth loop that separates with
Product Review Editor
Key Measurements
Summary
Bottom Line
The DJ-G7T handheld adds
23 cm operation to the usual 2 meter
and 70 cm bands. With a wide range
receiver and full duplex capability, it
offers a lot of value for the money.
k1ro@arrl.org
From April 2010 QST © ARRL
a plastic snap-together fastener, making it
harder to remove in a hurry. It fits a belt up
to 3 inches wide, handy for those 1970s parties. The battery pack on the back has two
1
⁄4 inch square metal pads for connecting to
the drop-in charger. Be careful not to put
the radio in your pocket along with spare
change or keys.
Lab Testing
Overall, the radio tested fairly well on the
three amateur bands it was designed for. With
a wideband receiver in a small package, some
design compromises must be made — in
particular placement of the IF (intermediate
frequency). Many models have the IF above
or below the 6 meter band, resulting in poor IF
and image rejection in that area. This is also
true with the DJ-G7T, where the IF of the sub
receiver is within the 6 meter band, so expect
images while listening to 6 or 10 meters.
You can listen to the main and sub receivers simultaneously, and even tune them to the
same band. I observed up to 6 dB of signal
degradation in the sub receiver with both receivers tuned to 2 meters in the dual listening
mode. Interestingly, with the main receiver
tuned to 2 meters, I noticed about 8 dB of
signal degradation with the sub receiver tuned
anywhere between 50 and 135.995 MHz.
Alinco attributes this to filter characteristics.
I didn’t observe signal degradation with other
main and sub frequency combinations.
The earphone jack has speaker level
output, not the lower level normally used for
earphones, so you need to be careful about
cranking up the volume. The audio was nice
and clean even at high listening levels.
I observed the specified transmitter power
output with the transceiver running from an
external 13.8 V dc supply, but was a bit less
than specified on 2 meters with the battery
pack. A nice surprise is this transceiver can
operate with as little as 4.5 V dc and still put
out a usable signal, a plus during emergencies.
On the Air
As previously mentioned, review the
manual to understand the use of the various
settings and functions. I found the manual
that came with our DJ-G7T difficult to understand and follow. Since then, Alinco has
revised the manual, and the new version is
available for download from their Web site
and is shipping with current production units.
With the new version (PS0597A, printed
on the back cover of the manual), I had no
trouble understanding the configuration
steps, most of which start by pressing the
FUNCTION button and rotating the concentric
knobs at the top of the radio.
The DJ-G7T has 1000 regular memory
channels that can be organized into banks of
100 channels. One is called a dual bank, which
stores both main and sub frequencies. The
From April 2010 QST © ARRL
Table 1
Alinco DJ-G7, serial number M000905
Manufacturer’s Specifications Measured in ARRL Lab
Frequency coverage: Receive: Main band, 136-169.995, 400 Receive,0.530-1299.995 MHz, 469.995, 1240-1299.995 MHz FM, NFM.
Cellular blocked; Sub band, 0.530-59.745 MHz FM, NFM,
transmit, 144-147.995, AM; 59.750-107.995 MHz WFM; 108 430-449.995, 1240-1299.995 MHz 475.495 MHz FM, NFM, AM; 475.5 FM, NFM. 805.995 MHz WFM; 806-823.995 MHz,
850-868.995, 895-959.995 MHz FM,
NFM, AM; 960-1239.995 MHz WFM;
1240-1299.995 MHz FM, NFM, AM.
Transmit, as specified.
Power requirements: 4.5-16 V dc; receive, Receive (max volume, no signal, lights
200 mA; battery save (1:4) average, 56 mA on) dual receive, 248 mA; battery save,
dual receive, 50 mA single receive; as specified.
transmit, 1.6 A @ 144 MHz, 1.8 A @ Transmit (high, med, low 2, low 1):
430 MHz, 0.8 A @ 1240 MHz (high power).† 146 MHz: 1.44, 0.95, 0.73, 0.55 A;
440 MHz: 1.55, 1.03, 0.84, 0.55 A;
1294 MHz: 0.75 A (high), 0.6 A (low).
Receiver Receiver Dynamic Testing
FM sensitivity: 12 dB SINAD, main band, Main band, for 12 dB SINAD: 146 MHz,
144/430 MHz ham bands, –15 dBµV; 0.17 µV; 440 MHz, 0.17 µV; 1294 MHz,
1200 MHz ham band, –13 dbµV; 0.19 µV. Sub band: 29 MHz, 0.16 µV;
Sub band, 30-470 MHz, –15 dBµV; 50 MHz, 0.16 µV; 146 MHz, 0.17 µV;
>470 MHz, –7 dBµV. 222 MHz, 0.6 µV; 440 MHz, 0.17 µV;
902 MHz, 0.62 µV; 1294 MHz 0.29 µV.
WFM sensitivity: 76-470 MHz, –6 dBµV; 100 MHz, 0.58 µV; 500 MHz, 0.52 µV;
>470 MHz, –3 dBµV. 1000 MHz, 0.71 µV.
AM sensitivity: 10 dB S/N, <50 MHz, –1 dBµV; 10 dB S+N/N, 1-kHz tone, 30% modulation:
>50 MHz, –6 dBµV. Sub band, 1 MHz, 0.53 µV;
3.8 MHz, 0.47 µV; 14 MHz, 0.4 µV;
50.4 MHz, 1.3 µV; 120 MHz, 0.68 µV;
145 MHz, 0.36 µV; 222 MHz, 1.0 µV;
440 MHz, 0.39 µV; 902 MHz, 1.0 µV;
1250 MHz, 0.44 µV.
Two-tone, third-order IMD dynamic range: 20 kHz offset*, Main band:
Not specified. 146 MHz, 57 dB; 440 MHz, 53 dB;
1294 MHz, 51 dB. Sub band: 29 MHz,
59 dB; 52 MHz, 63 dB; 146 MHz, 57 dB;
222 MHz, 56 dB; 440 MHz, 53 dB;
902 and 1294 MHz, 51 dB.
10 MHz offset: Main band:
146 MHz, 69 dB; 440 MHz, 73 dB;
1294 MHz, 62 dB. Sub band: 29 and
52 MHz, 56 dB; 146 MHz, 65 dB;
222 MHz, 71 dB; 440 MHz, 64 dB;
902 MHz, 67 dB; 1294 MHz, 83 dB.
Two-tone, second-order IMD dynamic range: Main band: 146 MHz, 84 dB; 440 MHz,
Not specified. 88 dB; 1294 MHz, 90 dB. Sub band:
29 MHz, 55 dB; 52 MHz, 74 dB; 146 MHz,
82 dB; 222 MHz, 48 dB; 440 MHz, 88 dB;
902 MHz, 94 dB; 1294 MHz, 80 dB.
radio offers a variety of scanning modes.
With testing complete, W1AW Station
Manager Joe Carcia, NJ1Q, set up to work
me on 1294.5 MHz (national simplex calling frequency) at lunch time. Joe helped me
adjust the DJ-G7T’s microphone gain, easily
set by pressing FUNCTION and then MIC and
then selecting one of four levels with a rotary
knob. Joe gave me a good audio report and
found that level 3 worked best for me, as I
like to speak a foot away from handhelds. The
receive audio from the 13⁄4 by 3⁄4 inch speaker
grill sounded good as well.
My First FM Satellite QSO
With full duplex capability, this transceiver appears to be well suited for FM
repeater satellites such as AO-27 and AO-51.
The dual bank memory is perfect for satellite
work because several frequency pairs are
necessary to compensate for the Doppler
shift that occurs during a pass.
On a late November afternoon, I checked
the AMSAT Web site and found an AO-27
pass only minutes away. I hurriedly entered
the frequency combinations necessary and
soon heard a QSO taking place — noisy,
with lots of fading. Clearly, a better antenna
was in order at my end.
I got an Arrow dual band Yagi designed
for portable use and was ready for another
pass. With headphones on, I could clearly
zero in on AO-27. After listening to a few
passes to observe the routine, I aimed the
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