biquad antenna digital TV

[Admin 2421]

No, the drawing is very good...!!!!

I'm going to make a simulation on this antenna.

[Admin 2421]

And yet, this antenna is not really good ...

[Admin 2421]

,,,the antenna according to E. Spindler....470 - 790 MHz

[tcl32 2]

will try it for next TV antenna project...many thanks Admin

 

Edited June 14, 2019 by tcl32

[tcl32 2]

Dear Admin.....may i know

1. what is the impedance between F F ??

2. can use standard 3C coaxial 75ohm directly beetween F F ??

[Admin 2421]

1) 240---300 Ohm

2) ,,,no...!!!

[aurel 22]

no ???

hmm as far as i know OPEN DIPOLE antenna have impedance from 50 to 75 ohm

and  CLOSED DIPOLE have 240 - 300

 

this one is OPEN DIPOLE

[Admin 2421]

The impedance is highly dependent on the construction details. In general, you can expect 100-400 ohms of impedance. The nominal impedance is generally considered to be 400 ohms.

[tcl32 2]

10 hours ago, Admin said:

1) 240---300 Ohm

2) ,,,no...!!!

so a macthing 4:1 balun must be used ???

[tcl32 2]

10 hours ago, Admin said:

1) 240---300 Ohm

2) ,,,no...!!!

Dear admin..

i have question of the picture shown below.

is it a matching impedance 75 Ohm ?? 

Edited June 15, 2019 by tcl32

[Admin 2421]

 I wrote to you above that the antenna has a 240-300 ohm impedance, so you need to adapt for a 75 ohm cable.

,,,something like that...

[tcl32 2]

dear admin,

but i still dont understand your drawing ....on what is  1000mm ??  is it a reflector 

also what is it 170mm  ...is it a director 

[Admin 2421]

,,,yes dear tcl32...!!!

[tcl32 2]

12 hours ago, Admin said:

 I wrote to you above that the antenna has a 240-300 ohm impedance, so you need to adapt for a 75 ohm cable.

,,,something like that...

Dear admin...i prefer ""gamma match"" if posible to match the antenna..

[Admin 2421]

And how do you want to do this?

[RC-Concepts 3]

After my parents complained that my previous DIY antenna (the common design of a pair of double fractal-elements matched  to 75ohms from 300ohms via a TV balun) could not pick up any overseas channels at their house, I made the Biquad antenna based on the first Biquad (581.68mhz in simulation) that was provided in this thread.  

I resized all the original dimensions (x 0.83) for my intended frequency of 682mhz  so that it could receive overseas HDTV channels at my parents house. 

A check with my VNA revealed that my resized antenna was tuned to the center frequency of 572mhz. It is usable for a range from 400mhz (1.5 SWR) to 750mhz (1.5 SWR). At my desired 682mhz, SWR is close to 1.3.

 Thank you admin, the design is great. Now, my parents are able to watch foreign channels. 

Here is my build and test video:

www.youtube.com/watch?v=-2KVS-wrvQM

 

 

 

[Admin 2421]

"""" a very good achievement RC-Concepts,,,,!!!!

 

 

[alhaba.production 6]

Any recomendation for feed ? I have large kenbontong grid. Thanks for advice.