quad four how much power?

[tejanodrum]

If my quad uses 14 gauge wire, how much power will it handle? I used a solid copper wire on my drive element so i could run more power. Will the 14 gauge handle 4000 watts?

</p>

 

[Jay in the Mojave]

Hello Tejanodrum:



Wow thats a lot of steam!



At 4000 watts come to 9 amps of current. Yeah that would handle the power.



But what about the Impedance Matching System? The RF voltage will be 447 volts.



Jay in the Mojave



www.a1antennas.com <img src=http://users.joplin.com/dutch64804/posticon44.gif ALT=":44">


</p>

 

[Jay in the Mojave]

Hello Tajanodrum:



Really!!!!!!!!!!!!!!!!!!



What type of 1 to 1 Balun did you try if I may ask? <img src=http://users.joplin.com/dutch64804/posticon60.gif ALT=":60">



Jay in the Mojave <img src=http://users.joplin.com/dutch64804/posticon44.gif ALT=":44">


</p>Edited by: <A HREF=http://p067.ezboard.com/bworldwidecbradioclub.showUserPublicProfile?gid=jayinthemojave>Jay in the Mojave</A> at: 1/14/05 6:37 am

 

[Jay in the Mojave]

Hello Tejanodrum & Marconi:



Yeah Thats how you would think that the Balun would work, NOT effecting the SWR. But they do as I have measured this also.



A neat test you can do, is place a 50 ohm none inductive resistor accros the Balun output terminals and measure the SWR.



This becomes someting that is a little more completed than just throwing up a Balun and things become all better now.



In Tejanodrum Quad Beam Antenna situation there may be more going here, than seeing the SWR going higher with a Balun Installed between the quad antenna and the Coax.



Its possible that the existing Quad feeding method is not properly set up, (NOT trying bad mouth anyone here) and the installation of the Balun showed that the antenna has a higher SWR when a Balun is installed. Again a Balun is supposed to choke off currents traveling on the out side of the coax shield. (that will cause false SWR measurements) And apply equal current to the driven element wires of the quad. ........... If the Balun is working right then it possible that the Quad is not properly tuned. As the SWR may be really at 2 to 1, which isn't all that bad.



If the existing Quad Beam Antenna without the Balun, has say a 1/4 wavelength of length of coax removed or installed and the SWR changes more than a few digits, this may indicated that the coax is apart of the antenna and different coax lengths will see different SWR measurements. Coming from the coax radiating from a imbalance at the feed point of the quad.



Then if the Balun is again installed, and the 1/4 wavelength of coax being removed or added does not change the SWR this indicates that the balun is working, and the quad antenna needs to be tuned.



I wounder if when the Balun was installed if the antenna worked any better or worse, even with the higher SWR?



When the 4 element quad is working correctly or even close, it will sigificinatly work better than the Maco V5/8 antenna



Tejanodrum e-mail I have a diagram that you can make a inexpensive Quad Balun, that could be compared to no Balun and the Balun you tried.



jay123a@qnet.com



Jay in the Mojave



www.a1antennas.com <img src=http://users.joplin.com/dutch64804/posticon44.gif ALT=":44">


</p>

 

[Jay in the Mojave]

Hello All:



Ok here is some info I have learned that I will share here.



When I first tested the Crusader 10K 5 Element Yagi Beam Antenna I saw a really low SWR something like 1 to 1.1



So I didn't give the matching to much thought. But the SWR was a lie as the beam worked like dog poop. It didn't have any directional features, it was a omni beam looking clod pile of aluminum. So I decided something was wrong, Hahahahahaha



Anytime a balance load such as a Yagi (with split driven elements), quad, log periodic, or dipole antenna is used, and feed by unbalanced Coax, a Balun must be used to choke off the RF Currents traveling down the coax outer shield, as this will significantly throw off the antennas performance. But may show a good SWR!!!!!!!!!



Oooops left out a paragraph..........



When a 1 to 1 Torid Current type Balun was installed, replacing the Coax Coiled Balun, the Beam got up and barked. I had to retune the elements and the Beta Match, but this was a significant learning point that should be shared.



But for a 4 element quad antenna I would think that a 50 to 100 Ohm Impedance matching Balun will need to be used.



Jay in the Mojave <img src=http://users.joplin.com/dutch64804/posticon44.gif ALT=":44">



www.a1antennas.com <img src=http://users.joplin.com/dutch64804/posticon44.gif ALT=":44">


</p>Edited by: <A HREF=http://p067.ezboard.com/bworldwidecbradioclub.showUserPublicProfile?gid=jayinthemojave>Jay in the Mojave</A> at: 1/16/05 12:50 pm

 

[Moleculo]

A note on the balun problem: I had read the chapter out of Reflections II on baluns before, but had forgotten one little part until I re-read it again yesterday. The important part for this discussion is that he noted that almost all commercially available baluns that use transformers are voltage baluns, not current baluns. If yours is really a voltage balun, it's the wrong tool for the job. If you can open up yours and take a look inside, that might tell us something. If you find it's just coax coiled up inside, then it's a coax choke balun and that is a current balun. In that case, you might have a bad SO-239 or other connector on the balun.


</p>