i hung kerrys true-talk 102 ft as inverted v about 3 mos ago. i have talked all over the world with no more than 100 watts. the metal mast will not affect the performance. it has to be the best made antenna in its class. pay more or pay less but you cant beat it for performance. kerrys product is number one in my opinion. fred
Why go round and round about this?
Those who answered on a technical basis are more correct.
Those who list their contact acomplishments and think it supports something are missing the technical side of the issues. As stated, contacts can often be made as well at 20 watts as at 100 watts, in many cases so what do contacts prove?
How would you know that you could or could not do better on a more correct antenna setup unless you see the technical side and make the changes and do the long term comparisons?
Why not try and understand that on different bands the impedence changes at the antenna terminals and is reflected at the radio termination by the changes in transmission line physics AND that radiation angle changes per band for an antenna at a fixed height.
As for the auto tuner, it depend on the tuner's range. If it sees an impedence within it's range, a match will be found. Dosn't make it correct or really fix anything just a transformation. It dosn't change losses in the system.
Changing the antenna length even by the few inches may be enough to "reflect" an impedence within the tuners range that the antenna would not at it's previous length.
Let me throw somthing else into this mix. I see on the use of my AT and looking at total output power into a matched condition with and without the AT inline, even into a dummy load that the AT may be responsible for as much as a 10 watt loss when in the circuit.
I can match the radio through an external tuner and it's watt meter will always show a 10 watt loss with the AT inline when all is flat matched.
Unless I am missing something, I see this as a lose in the AT.
So add this to an antenna that is not resonant and you lose even more.
The overall impedence the radio sees is a very complex summation of all the points in the system such that one can't just say with any ease, certainty or simplicity what is better or worse and why, unless you look at all the part and see where the largest issues occurr and reduce them with the best compromises.
According to the coax calculator here: http://www.qsl.net/co8tw/Coax%20Calculator.htm the 600 ohm open wire has 1/2 the loss at 20:1 as RG-213 does at 4:1.
Note that simply changing the G5RV's series matching section from 300 ohms to 600 ohms results in a change in coax SWR on 3.8 MHz from 3:1 to 34:1 so that particular modification is not recommended.
Outstanding! That would be of great interest if I ever consider using a G5RV, which is about as likely as me hitting the Powerball jackpot.
I use 4' fiberglass mast sections that I found on ebay. They were used by the military to support tents. I have my G5RV supported by these and is 40' up.
Don't get caught up in the "true talk" hype..PLEASE
Licensed in 1994 as KB0PTV, 5 wpm Extra-Lite
Cecil, I read your comments about 300 ohm twinlead, but I cannot imagine that any true ham would use such poor feedline for ANY ham antenna.
Right now, 400 ohm ladder line is in very scarce supply here in the U.S., and it could be a blessing in disguise ! I can envision many hams building their own open wire feedline to feed their doublet antennas ( I intend to ! ) and I believe we will all be the better for doing so !
That's JMHO, but I think it bears scrutiny !