1. TEST REPORT Twin LNB
Skytrack
JTU41 Twin LNB
of Jiuzhou
• excellent
performance with
high signal levels
• a rare exception:
manufacturers
gives the true
specifications
• perfectly suited
for multi-user
installations
• very high output
power
94 TELE-audiovision International — The World‘s Largest Digital TV Trade Magazine — 01-02/2013 — www.TELE-audiovision.com www.TELE-audiovision.com — 01-02/2013 — TELE-audiovision International — 全球发行量最大的数字电视杂志 95

2. TEST REPORT Twin LNB
Solid Performance their performance we did
not measure just one but
two samples of the JTU41
model. The external design
of JTU41 is classic. This is
Jiuzhou offers a wide not claim their LNBs have a tests we discovered that the the shape we are accus-
range of LNBs that suit the noise figure of 0.2 dB or even performance of Jiuzhou 0.6 tomed to when dealing with
needs of almost any user. 0.1 dB as so many other dB devices matches quite universal twin LNB for Ku
Our regular readers can re- competitors do. They prom- well, if not beat, the 0.2 dB Band with a 40 mm collar. It
member a number of test ise just 0.6 dB. Some casual LNBs of some other manu- has two F type connectors
reports dedicated to Jiuzhou customers (and we do not facturers. Now we wanted which can be covered with
products. What is so special want to call them “naïve”) to find out: is that also the a sliding bottom part of the
about this company: they do may think that Jiuzhou prod- case with their new Twin LNB plastic enclosure. Thanks
not over specify their prod- ucts are second class LNBs. JTU41? to that they will not be ex-
ucts. For example, they do Far from it! In our previous To be quite certain about posed to rain and snow and
01-02/2013
Jiuzhou JTU41
Solidly designed LNB
giving a very strong
■ One of the signal level
sample LNBs
during the test www.TELE-audiovision.com/13/01/jiuzhou
96 TELE-audiovision International — The World‘s Largest Digital TV Trade Magazine — 01-02/2013 — www.TELE-audiovision.com

3. Transponder Modulation and SR
10762 HL DVB-S 27500
the quality of cable connec- on 19.2° East or HOTBIRD rates vary from 2,500 up to cused on the output power 10845 HL DVB-S 27500
tion will be not degraded on 13° East as this is the 30,000 ks/sec and there are achieved from the same 10928 HL DVB-S2 30000
over time. Their weight is most typical application for transponders of both polari- transponders; this corre- 10972 VL DVB-S 27500
11010 VL DVB-S 27500
not high so they are suita- them here in Europe. This zations from low and high sponds to the LNB conver-
11045 HL DVB-S 10555
ble even for the dishes with time, however, we decided sub bands of the Ku-Band. sion gain parameter and 11054 HL DVB-S 2894
not so strong LNB supports. to make our test a little bit We turned our dish to modulation error ratio (MER) 11131 VL DVB-S 14815
Also their energy consump- harder. We chose TURKSAT TURKSAT and did the first which in turn corresponds 11177 VL DVB-S 27500
11220 HL DVB-S 30000
tion is moderate – 130 mA on 42° East. Some of its round of measurements with to a combination of a few
11231 VL DVB-S 30000
in our measurements, so it transponders are quite weak our reference high perfor- parameters: noise figure, 11283 VL DVB-S 27500
will not be a problem for any in our location and addition- mance single LNB. Then, we phase noise, isolation, im- 11324 VL DVB-S 30000
receiver or antenna switch. ally some of them transmit installed the first sample and age rejection and intermod- 11345 HL DVB-S 27500
11366 VL DVB-S 30000
Workmanship leaves noth- with low symbol rates. This measured its two outputs ulation. In other words, the
11386 HL DVB-S 30000
ing to be desired for this makes the test more de- (1A and 1B in our graphs). first parameter tells us how 11470 HL DVB-S 30000
class of products. manding. Finally, we did the same with strong the signal is and MER 11470 VL DVB-S 29950
We usually test this kind of The table below (Table 1.) our second sample of the is a measure of signal quality 11512 HL DVB-S2 30000
LNBs with one of the strong lists all the transponders we JTU41 (2A and 2B). at the output of LNB. 11512 VL DVB-S 29950
output power. Th Skytrack Our general conclusion is: 11553 HL DVB-S 30000
European satellites – ASTRA used for our test. Symbol In our analysis we fo- The first graph shows 11595 HL DVB-S2 30000
JTU41 had evidently a if you do not need to hunt for
11678 HL DVB-S2 30000
stronger signal than our very weak transponders and 12508 VH DVB-S 2532
reference LNB. Practically signals with very low symbol 12576 VH DVB-S 5925
for every transponder, both rate, the Skytrack Twin LNB 12593 VH DVB-S 2500
Jiuzhou samples delivered JTU41 will perform as perfect 12596 VH DVB-S 2848
12600 VH DVB-S 2500
higher output power by as many 0.2 dB devices of 12605 HH DVB-S 27500
about 5 dB on average. This other manufacturers. It is a 12621 VH DVB-S 3364
is a lot. It means that we can solidly designed LNB giving a 12633 VH DVB-S 4883
use long cables or high loss very strong signal level suit- 12640 VH DVB-S 6510
12656 VH DVB-S 4883
switches and still enjoy a ed even for very demanding
12676 HH DVB-S 2800
strong enough signal at the installations with long cables 12733 HH DVB-S 5700
■ Testing the
two samples of IF input of our receiver. and multiswitches. 12736 VH DVB-S 3703
Jiuzhou Twin LNBs
Skytrack JTU41
■ MER measurement results shown in the second graph are more balanced between the reference LNB and the devices under test.
■ Except for two weak transponders with low symbol rate where JTU41 performed slightly worse than the reference, it had no problem in
matching or even exceeding our reference for all remaining transponders. The difference between the outputs of the same twin device
was rather small for the majority of the test transponders.
98 TELE-audiovision International — The World‘s Largest Digital TV Trade Magazine — 01-02/2013 — www.TELE-audiovision.com www.TELE-audiovision.com — 01-02/2013 — TELE-audiovision International — 全球发行量最大的数字电视杂志 99

4. Expert Opinion More about this company
Very good performance for stronger signals www.TELE-audiovision.com/11/03/jiuzhou
+ Low LO drift
Low phase noise
– Slightly worse performance for weak signals
with low symbol rates
Jacek Pawlowski
TELE-audiovision
TECHNICAL
Test Center
Poland
DATA
Manufacturer Sichuan Jiuzhou Electric Group Co. Ltd.
Internet www.jiuzhou.com.cn
E-mail sales@skytrack.cn
Telephone +86-755-21389616 +86-755-26947264
Fax +86-755-27496486 +86-755-26947266
Model JTU41
Function Universal Twin LNB for Ku-Band
I/P Frequency Range 10.7 GHz ~ 12.75 GHz
O/P Frequency Range 950 MHz ~ 2150 MHz
L.O. Initial Accuracy ± 1.0 MHz (@ 25° C)
L.O. Temperature Drift ± 2.0 MHz (-30 ~ + 60° C)
L.O. Phase Noise -60dBc/Hz @ 1 kHz offset (Max.)
L.O. Phase Noise -80dBc/Hz @ 10 kHz offset (Max.)
L.O. Phase Noise -100dBc/Hz @ 100 kHz offset (Max.)
L.O. Spurious -50 dBm (Max.)
Noise Figure 0.6 dB
Conversion Gain 50 dB (Min.)
Gain Variation 8 dB (Max.)
Gain Flatness ±0.5 dB/27MHz
Isolation 20 dB (Min.)
Image Rejection 40 dB (Min.)
P1dB 0 dBm (Min.)
Output VSWR 2.5:1 (Max.)
DC Current consumption 200 mA (Max.)
Polarization Switching Voltage V:11.5~14V, H:16~19V
Band Switching Low:0 kHz, High:22 ± 4kHz
Water Proof Test +60°C water for 5 minutes
100 TELE-audiovision International — The World‘s Largest Digital TV Trade Magazine — 01-02/2013 — www.TELE-audiovision.com