Antenna Handbook

FTTH Network Solution

FTTx Internet Network solution 

consists of 2, FTTH and FTTB.
For small office, home, or SOHO, or apartment building. 

We called it a basic FTTx network project, which is usually low cost and simple service providing etc. 

(courtesy fiberoptictel.com)

  • If a fiber is run to a panel inside each subscribers apartment unit (eg: Home or SoHo), it is FTTH.
  • If instead the fiber goes only as far as the apartment building’s shared electrical room (either only to the first floor or to each floor), it is FTTB.

The basic function of FTTH/FTTB broadband access solution, like data, or internet service, IPTV etc. (courtesy fiberoptictel.com).

How To Optical Fiber test Measurements Using OTDR ?

Optical fiber cables are tested for attenuation using the cut back method or back reflection method . The cutback method is mainly used in test at the manufacturing facility and the back reflection method is normally used in the field and in the manufacturing facility for some tests. An optical time domain reflectometer (OTDR) is the portable optical test set used in the field for pre- and post construction fiber measurements. The backscatter concept is illustrated in Figure 1




A lead-in or launch fiber is used to eliminate the effect of dead zone created from the OTDR fiber interface connector. A lead-in fiber is a fiber several hundred meters in length that connects the OTDR to the fiber being measured. It provides a useful fiber trace for the entire length of fiber under test. Since it provides backscatter power leading into and out of the initial fiber connection in the fiber undertest, a more accurate measurement of fiber length and total end-to-end loss can be made. The lead-in fiber is a commercially available OTDR accessory with a connector on one end to match the OTDR network interface and a connector on the other end to match the connector encountered on the fiber under test or in this case a bare fiber with a mechanical alignment fiber connector, such as an elastomeric lab splice. Lead-in fibers are useful to locate short distance faults and making loss/attenuation measurement in real time mode. This document explains howto use lead-in fibers.
One of the OTDR equipment come from Fluke Networks

Measurement Procedure.

Block Diagram 

This is a schematic diagram of testing optical fibers using an OTDR with a lead-in or a launch fiber.

Procedure 

Connecting Dummy Fibers / Pigtails to OTDR: Clean optical connector in end of lead-in fiber that will mate with the OTDR using isopropanol and lint free wipers. Connect it to the OTDR output so that a fiber trace can be observed. A square peak on the fiber trace (see Figure 3) will mark the start of the trace. Next to this peak OTDR traces should be a smooth with a continuous slope. Adjust the connector to obtain the OTDR trace as shown in Figure3.

DIY Six Stage Attenuator for High Frequency HF

If you have to deal with radio frequency more than very rarely, it is helpful if you can easily weaken the signals in discrete steps. 

So you can e.g. Bring the output signal of an HF generator to a different level than would only be possible with the generator's adjuster. 

There are many applications for a concealer when comparing or repairing receivers or with radio devices. Unfortunately, professional attenuator are quite expensive. 

Doing it yourself is worthwhile here because expensive electronics are not required
The Circuit Diagram of Six Stage Attenuator from Elektor Elektronic July Edition 2017 in Germany language 

Circuit Diagram


PCB Lay Out

Final Six Stage Attenuator Prototype with aluminum case








With Six Stage Switches for 0..31 dB in 1 dB Step
Prototype Final

Frequency Response 0....-31 dB



Radio Straight or Crystal Radio for Science Project or Hobbyist



OA70 / IN34 / IN60 is Germanium Radio, choose only one type.
Antenna high from Ground is high is possible, ground is a must to Steel Water pipe, or making one from a piece of copper approximately 1 meter down to the ground, so will be voltage between ground and radio wave pick up by antenna.

I have build this Radio and connected input speaker to line input notebook and running with Open Lab software and can pick up Radio Signal from about 6 km air distance.

====+  Parts List for   +====

10 nF                              1   Capacitor


VC 500 pF                      1   Variable Capacitor


OA70/IN34/IN60             1


 GND                               1   GND
Termination Ground

108 Turns,12 Turns        L Tap between 108 Turns and 12 Turns

8-2000 Ohm  1   SPKR or Earphone 8 - 2000 Ohm , you can get this in junk shop or at ebay.com

RF Connector Male and Female For Antenna Connection
 

50 Ohm Coaxial cable for Antenna


Electronic Project Box


Antenna for LW,MW,SW and AM 

Sun Switch With Transistor 2N3055



2N3055 is Power Transistor and Amplifier Transistor for General Purpose and can act as Photo Transistor by cutting the "hat cover" of this transistor. This photo transistor function of 2N3055 can be taking the advantage as switching function with transistor. This circuit using 2 transistor which is 2N3055 and BD139. If there is no sun light or the light is not enough for Transistor 2N3005 to deliver, so R1 will give current to TR2 BD139 ,and this transistor will turn on Lamp on the Output of Circuit.








If The Sun Light which flows to "hat cover" of TR1 2N3055 enough, TR1 will deliver and will grounded Base of TR2 BD139 and will Turn Off The Lamp.R2 and P1 will improve switching system of the Transistors and The Light of Lamp Intensity could be regulated by P1.


At the below figure is Stripboard or Veroboard for the circuit. This Veroboard using DIY LC software. 

Parts Lists of Components :
Transistor TR1 2N3055

Transistor TR2 BD139

  
Resistor R1 4K7
Resistor R2 10K
Trimmer Resistor P1 1M
Lamp 9 V / 400 mA
Battery 12 V and Case battery
 

Universal PCB
  
Box  for the Circuit