I really don't know, important is the velocity factor which is different from cable to cable..this RG58 clone was like .86 instead of a good quality RG..which is .66. Probably a good quality cable will do a better job..consider the radio waves traveling at the surface of the cable not inside the core..
according to the table i found at wiki, VF of RG58 is 0.81 . Because of that you changed the size of elements in Part 2? Can you tell me how to calculate size of parts, if you have other type of coaxial cable, to get 868Mhz?
@@viocaia Thank you. I dont have network analyser but Ill try to make one and we will see how will it operates. Did something similar for wifi antena but I had calculation for that. This will help, thanks again
@@xIRFOx Just follow the design from part 2 and it's working for sure.Be careful not to short the dipoles..check with a multimeter each segment after you do solderings. Good luck!
Thanks! Good idea with more light..About SWR I ordered and SDR radio and I'll try some tests.So far is working great but I don't have a compare to..the original is no way to reference.
@@viocaia Very nice. Just one question. That feeding part of telescopic antenna (half length of one antenna part), you stripped down outer insulation of coax cable and just pulled that tube over braided shield, is that right?
Before testing I covered the wrapped elements part with solder, to avoid any coil effect.Just a regular shield.
Thank you very muck for your videos! What is the influence on the antenna if you use higher diameter coax? Will it be better?
I really don't know, important is the velocity factor which is different from cable to cable..this RG58 clone was like .86 instead of a good quality RG..which is .66. Probably a good quality cable will do a better job..consider the radio waves traveling at the surface of the cable not inside the core..
according to the table i found at wiki, VF of RG58 is 0.81 . Because of that you changed the size of elements in Part 2? Can you tell me how to calculate size of parts, if you have other type of coaxial cable, to get 868Mhz?
Exactly...my first attempt was done considering 0.66 for RG58, totally wrong..
I can say the antenna is working great , sending beacons more then 60km..way better then the standard 3db..
I use this page for inspiration jeroen.steeman.org/Antenna/collinear-coax
@@viocaia Thank you. I dont have network analyser but Ill try to make one and we will see how will it operates. Did something similar for wifi antena but I had calculation for that. This will help, thanks again
@@xIRFOx Just follow the design from part 2 and it's working for sure.Be careful not to short the dipoles..check with a multimeter each segment after you do solderings. Good luck!
Very nice video and explanation. Aslo your audio is very good. However I would like to see a bit more light in your videos.
Thanks! Good idea with more light..About SWR I ordered and SDR radio and I'll try some tests.So far is working great but I don't have a compare to..the original is no way to reference.
Just reached 45Km with it
@@viocaia Very nice. Just one question. That feeding part of telescopic antenna (half length of one antenna part), you stripped down outer insulation of coax cable and just pulled that tube over braided shield, is that right?
@@alenramic5077 You don't need to take the plastic off..just open lik 5mm of shield and solder to the tube
@@viocaia thx for quick answering. So just to strip down e.g. 5mm of shield and solder braided shield to tube.
Nice antenna!
Yes it is! And working great..