aurel

WOW

long time i don't visit this forum

Dude above with double biquad made mistake 

30 17 mm

If the relector is connected to GND of cable then is better if is of aluminum

yes it is very hard and wouldnt wastimg my time with such design

I think that too, you must find any old satelite antenna dish for such a large distances 

I dont know what kind of biquad is this ,,but  biquad ia biquad 

i think offset 

oK i will try add batwing to satelite dish dia 80cm

Isolation between ports,i don't get it , do you mean isolation between director and central metal rod/screw ?

I recently build one and work well, just is a sensitive to polarization.

Jomy ..i have old satelite dish and i have in plan to use it to try pick up wifi signal ... air line cca 3- to 4 km i am not sure..

so is it better use simple biquad with reflector and add it to satelite dish (60cm...or 70 i am not sure too) or ad patch similar to this 'gun' antenna 

i mean just two reflector 90mm and patch 68mm...

thanks !!

I suspect Jomy that this must be a fake...

better than double biquad....ha ha 

what kind of trick is that?

yeah that one is really good and expensive,,,,BUT

why not use ordinary satelite antenna dish and add wifi element 

Hi jomy

somewhere is stated that this type of antenna is circular porized, that is not true at all, i recently have some problems with this antenna 

my son use it on another computer complain to me that he have bad signal, he mean low signal from AP..

after looking i think that something else is wrong ,AP send H polarized wifi signal and when we desolder and solder again coaxial cable inner wire into V

position msignal becomes large and very very good , strenght more than 86%...So people be carefull how you polarize youer antennas!

I use it as dipole on reflextor 12x12cm and work ,of course there are better antennas but work.

Yes i made it and connect it yesterday to try ,,,ok it work in horizontal polarization

Thanks i will try to make it!

Ooups not 120 than 72 mm

Jommy what you think about this one:

Jomy do you can simulate only this double dipole with reflector...without directors ?

Well Ok ,maybe i try to build .i have one spare piece of 12x12 cm zinc metal plate as reflector.

Yomi it is video about double - dipole with reflector, i must say that i never see before such a antenna .

Is is maybe better than classic biquad?

IF IS ,then is worth to build..right? 

Here it is :

.

Quote

The driven element is fed at centre so its two halves must be insulated where the boom supports them.

Exactly....and i don't what is mumbo.jumbo simulation talks means

I must repeat my question :

Do you have on your wifi card any program which show you signal strength?

So it is very simple to test..in which case is better or larger signal ,with isolation from metal rod or without isolation.

I can bet without  that better reception is with isolation between active plate and metal rod.

please let me know do you can do that test! 

Thank you jomy on simulation.

Quote

 

 

vars-cat

forget about simulation ,every simulation show optimal or ideal values and don't represent real things.

Do you have on your wifi card any program which show you signal strength?

If you have such a program you will see a difference in signall strenght when active plate is connected to rod and when is not .

There is no speculation about that and i know that from my experience.

This antenna as such is asimetric half wave dipole  and as such require isolation between active element and radiator/reflector which must be grounded.

Thank you jomy on simulation.

Quote

 

The tube is needed for reliability. 
You don't need to isolate anything anywhere. 
The cable braid must be in contact with the largest disk.

Also:
Instead of the RG-58 cable (high signal loss), it is better to use rg-6.
The antenna made of copper cannot be used on the street.

 

vars-cat I am really dissapointed in your explanation, active plate 68mm dia MUST BE ISOLATED from metal rod, big last metal plate is REFLECTOR  90mm

which there is no need to be isolated from metal rod, finished copper plate can be spayed with metal primer to protect copper.