co-phaze coax and antenna tuning

[gamegetter]

that would work if he did not mind changing signal pattern,
but i would just use the shortest length coax necessary to get me from radio to antenna. jmo

one effect of phasing antennas is supposed to be to even out pattern irregularities thereby eliminating signal fade-if the trade of between this and the single antenna is acceptable to operator, then by all means.

 

[W5LZ]

"one effect of phasing antennas is supposed to be to even out pattern irregularities thereby eliminating signal fade..."
Actually, that's not a good, or valid reason at all. The only benefit from phasing antennas is to either increase gain or make the antenna system directional. That could be construed as 'even out pattern irregularities', but not really.
- 'Doc

 

[gamegetter]

u lost me in your play on words!



but i think u said the same thing i did

are the words "that can be construed" and "one effect of" not about the same?

 

[W5LZ]

... only if you 'twist' words hard enough. 'Misinterpreted' would be another way of saying it.
- 'Doc

 

[longhaireddwb]

Here is what i found. After tuning as i did and cutting coax the impeadance was 42. I went ahead and retuned at the feedpoint with my analyzer adjusting both antennas the same at the same time and got it to a 1.2 at ch19 and 1.4 and 1.5 at both ends of the band. Impeadance is now 48.

I thought that if the whips were not long enough i would add a jumper of 50 ohm between radio and phazing coax but didnt need to.

From my understanding going phazed coax changes the pattern so its more non directional. Cant think of the right word right now. So i agree with doc on the reason.
As far as running single coax, he never knows when he might be in a diff truck and its a company truck and they dont let him mess with it.

We will see how it works next week and ill let you all know.

 

[Captain Kilowatt]

Phasing antennas is not as simple as it may seem. The length of the phasing lines depends on what you want to achieve for a pattern shape as well as how far apart the antennas are. The impedance to be matched also determines the length required but that is a separate issue from pattern shaping. To further complicate matters one phasing line can be longer than the other and that will change the pattern shape. If the longer line is switched with the shorter one the pattern will change again. Lots and lots of stuff happens when phasing lines are involved however most people only understand one thing and that is that you need one to run two antennas and beyond that they know nothing.

 

[longhaireddwb]

I understand Cap Kil. That does make sence. In this case i think shortening both sides by four inches might have made the antennas longer but what do i know. I think it will all work out fine. Ill let you know how well it works.

 

[longhaireddwb]

I understand Cap Kil. That does make sence. In this case i think shortening both sides by four inches might have made the antennas longer but what do i know. I think it will all work out fine. Ill let you know how well it works.

 

[longhaireddwb]

As far as spending money on a vehice, im planning on buy a car anyways. The old pickup needs to be retired anyways. Might go with something like the chevy volt and not fully electric. Like i said this is all just ideas and i got more of them then i got money.

 

[longhaireddwb]

Oops. Got my threads mixed up.
Can someone move it?
Thanks.