Advertisment: Broadband via satellite
Advertisment: Worldwide satellite services from Ground Control Company

www.satsig.net

Satellite Internet Forum.

Welcome, Guest.        Forum rules.
      Home            Login            Register          
1  VSAT technology and installation / Dish pointing and alignment / How to Process High-Accuracy Panel For Ka Band Antenna
 on: Sep 11th, 2023 at 8:48am 
   
High-precision antennas are the key equipment of the satellite communication system, especially for high-frequency antennas such as Ka band antenna.

The main reflector surface of large and medium-sized antennas is composed of dozens or even hundreds of single panels. The accuracy of a single panel is the basis of the accuracy of the antenna’s main reflector surface. Generally, the accuracy of the main surface of C, Ku band antenna and other band antennas is required to be 0.6~0.7mm (r.m.s). The single panel is  stretched on a stretched film, and then riveted on the envelope riveted tire. The accuracy of the panel can reach 0.2~0.3mm (r.m.s). The ka-band antenna surface accuracy requirement is 0.2~0.3mm (r.m.s), and the accuracy requirement of a single panel is 0.11mm (r.m.s). For such a high surface accuracy, the traditional molding technology obviously cannot meet the requirements. On the basis of traditional technology, we have developed a new high-precision panel forming technology, that is negative pressure forming technology.
1.Introduction of negative pressure forming technology
The main reflector panel of the large and medium-sized antenna is riveted or glued by the skin and ribs, and the material is generally duralumin.
...

...

Copyright © www.antesky.com
The skin of the panel is stretched and formed on the skin stretching template. After trimming and shaping, the skin is vacuum-adsorbed on the high-precision negative pressure forming template, and the stretched high-precision ribs are combined with the high-precision negative pressure molding with room temperature curing glue. After the skins are glued together and cured at room temperature, 3 to 4 rivets are removed from the mold and riveted on each rib to form a high-precision panel, as shown in Figure 1.
2.Production process of negative pressure forming

2.1 Manufacturing of high-precision vacuum suction mold tires

Adsorption mold tire is the basic mold for panel molding, used for skin stretching and panel negative pressure molding. Therefore, the mold must have sufficient rigidity and precision, and the temperature deformation coefficient of the material must be as small as possible.

Design of vacuum adsorption mold tire
The vacuum suction mold tire adopts a box-type cast steel structure. In order to increase the rigidity of the mold, how to add “#”-type reinforcing ribs in the box structure, and 120mmX120mm of <3mm adsorption holes are evenly distributed on the mold surface to ensure the adsorption accuracy of the skin and mold tires.

Manufacturing of vacuum suction mold tire
The surface accuracy of the vacuum suction mold tire is required to be 0.3mm (r.m.s), and the accuracy is high. In order to ensure the accuracy of the mold tire, the following manufacturing process is determined;

Casting Blank—Annealing—Assembly Welding Blank—Annealing (Artificial Effect)—Natural Aging—Rough Machining—Annealing—Finishing— Measuring Machine Inspection — Fitter Polishing — Retest

When casting the blank, the wooden mold casting and the process plan of correcting the thermal deformation are used, which finally ensures the uniform machining allowance of the castings. The process that combines artificial aging and natural aging not only ensures the stability of the mold tire, but also ensures the processing cycle of the mold. In the mold processing, the rough and fine processing is selected separately, especially in the finishing stage, the precision CNC milling machine is used for processing, and the process plan of the fitter to polish the high points according to the test data, and finally ensure the accuracy of the vacuum adsorption mold tire. The accuracy reaches 0.024mm (r.m.s), which meets the requirements.

2.2 Manufacturing of rib stretching and pressing tooling

Rib stretching mould
The panel ribs are formed by stretching ribs on the rib stretching mould. In order to reduce the influence of the environmental temperature difference on the rib sticking mold, the rib drawing mold is made of carbon steel, just like the vacuum adsorption mold. The manufacturing error requirement of the rib drawing mould is 0.03mm (r.m.s), the ring rib mould is processed by vertical lathe, and the longitudinal rib mould is processed by CNC milling, and all meet the requirements after testing.

Compact tooling manufacturing
C and Ku band antenna panel compression tooling generally use rigid compression. high-precision panel requires high precision, rigid compression and will cause uneven compression force local deformation of the skin or ribs. So the special elastic compression tooling is equipped with a adjustable spring at each compression head position. The compression force can be adjusted to achieve a good performance by adjusting the length of the spring.

2.3 Selection of Structural Adhesive

Structural adhesive directly affects the rigidity, service life and stability of the panel. In order to improve the reliability of antenna panel, the adhesive with high bonding strength, strong resistance to atmospheric aging and good water resistance should be used when selecting. In order to facilitate the operation when bonding the antenna panel and be suitable for the production of large workpieces, room temperature curing glue should be used, and the curing time should be relatively short, and the glue with a certain operating time.

2.4 Ka band Antenna Panel production process
...

Copyright © www.antesky.com
Diagram of panel production process for Ka band antenna
The panel manufacturing process is the basis to ensure the accuracy and service life of the panel. The vacuum adsorption panel forming process is a brand new process. We have developed the process shown in Figure 2 for reference.

Skin stretch forming and rib correction
The accuracy of skin and rib will affect panel accuracy to some extent. Before the panel is formed, the skin needs to be calibrated on the vacuum suction mold, and the ribs need to be calibrated on the rib drawing mold.

Skin vacuum adsorption
The skin is aligned on the vacuum forming mold, and vacuum is pumped with a vacuum pump. The maximum non-mold gap between the skin and the mold tire is less than 0.5mm.

Rib gluing and fixed
The surface of the ribs must be coated evenly, and the gluing must be completed in a short time. The rubber strips are fixed on the vacuum forming mold with elastic rigorous tooling, and the length of the elastic compression tool spring is adjusted to make the compression force suitable.

Curing
The curing temperature should be consistent with the temperature of processing and testing the vacuum adsorption mold, and the temperature difference should not exceed 5°C. In the state of vacuum adsorption, keep for a period of time until the glue is basically solidified before other processes can be carried out.

Riveting panel
The number of rivets will directly affect the accuracy of the panel. When riveting, the position and number of rivets on the panel must be determined reasonably, that is, one rivet is riveted at each end of the rib for short ribs, and one rivet is riveted at both ends of the ribs and the middle of the ribs for long ribs.

Surface treatment
When applying glue, sufficient glue should be applied to ensure that the glue fills the joint surface. The excess glue squeezed out during assembly needs to be scraped off or scraped into an uniform shape, which is tightly attached to the glue seam. This work should be carried out before the glue is not cured.
2.5 Inspection of panel accuracy

The accuracy of the single panel of the Ka-band antenna requires about 0.1mm (r.m.s). The traditional measuring method of level and height ruler

2  Service Providers / Satellite Internet - Europe / Re: BUC status
 on: Aug 29th, 2023 at 11:21am 
   
Hi,
Thanks for your input on this. Yes the BUC LED is green and the 10MHz is equally enabled. Will explore other options you mentioned and see how it goes.
Thanks

[/quote]

Quote:
Some characteristics of the NJT5669F BUC:
RF output power: +37 dBm (at -1dB gain compression point)
Gain: 61 dB
DC volts: +24V (+15V to +30V) DC
DC power: 48W max
Mute (therefore no output power): LO unlocked or no 10MHz reference
LED indicator: Green = LO locked. RED: LO unlocked or no 10MHz reference
Note: No mention of any telemetry.
Is the BUC LED showing green ?  Is the 10 MHz reference supply activated ? Is there anything in the IF cable that is blocking 10 MHz?

I don't know if the X3 or X7 modem have the ability to measure the DC volts and DC current being fed to the BUC.  If anyone can help please say here.

Meanwhile you might consider making up a test rig with male/female F connectors and a resistive tap and measuring the voltage using a voltmeter. Measure the resistance of the IFL cable and repeat the voltage measurement at the other end. Calculate the current.

It is particularly important to follow exactly the section about "1 dB Compression Point and Maximum Power" in the user Manual.
https://www.satsig.net/forum-archive/idirect-setting-modem-output-power-1dB-comp...
Plot your graph of Pout versus Pin, with help from the NOC, like the example above for a 3W BUC ( 3W = +5 dBW = +35 dBm)
This example is from the iDirect User Manual, which you should follow.

Always start with lowest modem output level and increase slowly in 1 dB steps until the NOC can see your CW carrier on the correct frequency, correct polarisation and correct satellite!.

Set the modem output level for the P1dB compression point as the maximum allowed modem output level. I cannot stress too strongly that you must not allow the BUC to go beyond the -1dB compression point as this will degrade the error rate of your own signal and cause interference to others. Only very few models of BUC (such as expensive higher power types) have protective power limiting circuits that quickly trip out to Mute if an excessive input level is applied. Hopefully the trip off is fast enough to prevent permanent damage to the output transistors.


3  VSAT technology and installation / Satellite dish installations - pictures and descriptions / Antesky 2.4m Moveable Flyaway VSAT Antenna on Sale
 on: Aug 28th, 2023 at 2:42am 
   
Previously, we showed the detailed introduction of 2.4m Portable Flyaway VSAT Antenna with manual drive mode, which was installed in Senegal in 2019. This 2.4m Portable Flyaway VSAT Antenna is configured with 9 pieces of carbon fiber panels of light weight and compact pedestal for cost-effective package of which outside packaged with wooden carton and inside of aviation carbon fiber cases for protecting components from damaged during transportation. Moreover, it can workable for C/Ku/Ka band as your option.

We had been in manufacturing antennas and related accessories equipment for years, according to our experience, it is not easy to realize offset feed type of flyaway antenna with excellent performance. But after years researching, we Antesky made it successful in high gain value as well as low VSWR and these are in batch producing now.

Let us take 2.4m Portable Flyaway VSAT Antenna  as an example. These two type are all with offset feed and 9 petals of carbon fiber panels. And the difference between manual and automatic type is the design of pedestal and El push rod where the cables are integrated in automatic pedestal for controlling and rotating antenna to align satellite quickly . Plus the cables, we strengthen the pedestal with 2 rings of support pull rods compared with manual flyaway antenna. Here please refer the components introduction for both manual and automatic type .
...

Components of 2.4m Automatic Portable Flyaway VSAT Antenna

...

Components of 2.4m Manual Portable Flyaway VSAT Antenna

Since 2.4m manual and automatic 2.4m Portable Flyaway VSAT Antenna  have the similar structure the same assemble steps are the same. The installation can be completed without requiring any other tools by two qualified technical persons in 15 minutes. They can finish assembling smoothly based on the diagram attached. Also, we took photos for each component of 2.4m flyaway antenna and you can view to learn further.
In addition, videos are available and please find from Youtube thanks.
https://youtu.be/SyD3Oy1goU0
Installation video of 2.4M Manual Moveable flyaway antenna
https://youtu.be/pWNtYQLjN_g
Installation video of 2.4M Motorized Moveable flyaway antenna
We have Portable Flyaway VSAT Antenna  both manual and automatic available in stock from 0.75meter to 2.4meter. If you are looking for the offset portable flyaway antenna, please contact with Antesky at sales@antesky.com

4  Service Providers / Satellite Internet - Europe / Re: BUC status
 on: Aug 26th, 2023 at 8:51pm 
   
Some characteristics of the NJT5669F BUC:
RF output power: +37 dBm (at -1dB gain compression point)
Gain: 61 dB
DC volts: +24V (+15V to +30V) DC
DC power: 48W max
Mute (therefore no output power): LO unlocked or no 10MHz reference
LED indicator: Green = LO locked. RED: LO unlocked or no 10MHz reference
Note: No mention of any telemetry.
Is the BUC LED showing green ?  Is the 10 MHz reference supply activated ? Is there anything in the IF cable that is blocking 10 MHz?

I don't know if the X3 or X7 modem have the ability to measure the DC volts and DC current being fed to the BUC.  If anyone can help please say here.

Meanwhile you might consider making up a test rig with male/female F connectors and a resistive tap and measuring the voltage using a voltmeter. Measure the resistance of the IFL cable and repeat the voltage measurement at the other end. Calculate the current.

It is particularly important to follow exactly the section about "1 dB Compression Point and Maximum Power" in the user Manual.
...
Plot your graph of Pout versus Pin, with help from the NOC, like the example above for a 3W BUC ( 3W = +5 dBW = +35 dBm)
This example is from the iDirect User Manual, which you should follow.

Always start with lowest modem output level and increase slowly in 1 dB steps until the NOC can see your CW carrier on the correct frequency, correct polarisation and correct satellite!.

Set the modem output level for the P1dB compression point as the maximum allowed modem output level. I cannot stress too strongly that you must not allow the BUC to go beyond the -1dB compression point as this will degrade the error rate of your own signal and cause interference to others. Only very few models of BUC (such as expensive higher power types) have protective power limiting circuits that quickly trip out to Mute if an excessive input level is applied. Hopefully the trip off is fast enough to prevent permanent damage to the output transistors.

5  Service Providers / Satellite Internet - Europe / Re: BUC status
 on: Aug 26th, 2023 at 4:18pm 
   
Quote:
What model of iDirect router do you have and what model of BUC ?
I hope someone can help you.

Best regards, Eric.




Hi,
Thank you for your response. I use X3 & X7 model of the i-direct and C-band BUC Model: NJT5669F.
Thank you.

Regards
[#Quote]

6  Service Providers / Satellite Internet - Europe / Re: BUC status
 on: Aug 25th, 2023 at 4:14pm 
   
What model of iDirect router do you have and what model of BUC ?
I hope someone can help you.

Best regards, Eric.

7  Service Providers / Satellite Internet - Europe / Re: BUC status
 on: Aug 25th, 2023 at 1:47pm 
   
Hi,
Please what command can I use to check Tx voltage and Tx current of a BUC
I have tried several commands including tx IFLDC voltage but no headway. Likewise the rxdiag while txdiag not a recognizable command.

Thanks for your time
[#quote]

8  VSAT technology and installation / Hub and VSAT satellite equipment for sale and wanted / Used Mission Microwave 200 Ku-Band BUCs
 on: Aug 11th, 2023 at 10:51pm 
   
We are currently offering the following:

2 x KU1-200B-D6-6130410 200W Mission Microwave Ku-Band BUCs 13.75-14.5GHz /w 1:1 Redundancy.

3 x KU1-200B-A1-1130410 200W Mission Microwave Ku-Band BUCs 13.75-14.5GHz /w 1:2 Redundancy

Also comes with Redundant controller model # 01-10-0035-400

Please contact us if you are interested.


Sincerely,

Alex Stanton
IK Tech Corporation
alex@iktechcorp.com

9  VSAT technology and installation / Hub and VSAT satellite equipment for sale and wanted / Used/Refurbished iDirect Equipment
 on: Aug 11th, 2023 at 10:48pm 
   
Hello,

We currently have for sale the following iDirect products:

X3 Modems
X5 Modems
X7 Modems
e8350 Modems with and without FIPS
iDirect 5100 Modems
iDirect 5300 Modems
Evolution E1M1 line cards


Alex Stanton
IK Tech Corporation
alex@iktechcorp.com

10  VSAT technology and installation / Hub and VSAT satellite equipment for sale and wanted / iDirect 15100 HUB For Sale
 on: Aug 11th, 2023 at 10:46pm 
   
     PART NUMBER      QTY       CONDITION
HUB 15100      E0001219-001 REVP      1       USED, PULLED FROM LAB
  DUAL RCM MODULE                  
  TRIPLE FAN MODULE                  
  eM0DM-FIPS                  
  eM1DM-FIPS                  
  eM1DM-FIPS                  
  eM0DM-FIPS                  
  DLC-T      E0002272-0001            
  DLC-R      E0002271-0001            
  eM1D1                  
  DELL 420 1U SERVER W/ RAILS                  
  DELL 420 1U SERVER W/ RAILS                  
RCM MODULE (REFERENCE CLOCK MODULE)      9100-0044-0003 REVA      4       NEW IN BOX
RCM MODULE CABLES 9 POS CMD TO CMD 72"      834219051      8       NEW IN BOX
ICONNEX E850MP      K0000044-0002 REVF      1       NEW IN BOX
9350      E0002482-001 RevE      2       USED, PULLED FROM LAB
8350      E0000051-0004 RevJ      1       USED, PULLED FROM LAB
X7 (DC POWER)      E0001239-0004 Rev 0L       1       USED, PULLED FROM LAB

For more information please contact us directly.

Alex Stanton
CEO / President
Toll Free: 888-664-9975
Direct: 619-244-0408
Fax: 800-618-5761
www.iktechcorp.com ;