antentopSince2 July

** PLEASE DESCRIBE THIS IMAGE **
** PLEASE DESCRIBE THIS IMAGE **

 

 

 

 

Antentop is FREE e-magazine devoted to Antennas and Amateur Radio an

Special page devoted to

Antenna Switching Units

Custom Search

 

ANTENTOP- 01- 2018 # 022

Antenna Switching Units

 

 
How it works: RF voltage for antenna and control voltage for RF relays are going through one coaxial cable. The RF and Control voltages are separated at input and output of the coaxial cable with help of RF chokes. Inside the unit A1 installed main transformer that provides supply voltage for RF-relays. Logical for the code/decode circuit is very simple. If supply voltage is not coming to the coaxial cable then antenna # 1 is switched on. If the voltage in negative polarity (relative to the braid of the coaxial cable) is going to the coaxial cable then relay K1 powered up and it is switched on antenna # 3. If the voltage in positive polarity (relative to the braid of the coaxial cable) is going to the cable then relay K2 powered up and it is switched on antenna # 2. If the AC is going to the cable then both relay K1 and K2 powered up and there is switched on antenna # 4.

 

The RF relays used in the unit A2 should all use the same switching on voltage. Relay K2 is DPDT Relay. There is possible by such relay on e- bay or at some other places (MOUSER, DIGI-KEY). Anyway the relay may be substituted by common use SPDT Relay. Inner core of the coaxial cable should withstand both the antenna RF current and the switching on RF relay current.

 

Design of the unit A1 is shown in Figure 14 (inside- 14A, front 14B). Design of the unit A2 is shown in Figure 15 (inside: 15A - front: 15B).

 Unit A2 that placed on the roof should be protected from atmospheric influence- from direct contact with rain, wind, and snow. In perfect deal the unit should be hermetically sealed. It is very good if the unit may be installed in dry place, for example, in a loft or attic of the house.

 73! VA3ZNW

 

Figure 14 Design of Unit A1

 

 

 

 

Figure 15 Design of Unit A2

 

  

www.antentop.org

Page- 86

 

80 81 82 83 84 85 86

 

Lightning Links to Open Book

 

Just for Fun:

Map IP Address
Powered byIP2Location.com

Thanks for your time!

Last Updated:

June 24, 2018 18:14

** PLEASE DESCRIBE THIS IMAGE **

** PLEASE DESCRIBE THIS IMAGE **

2003entop