Horizontal and Vertical beam running together through a T connector?

[hotrod]

something i think most missed. using dx to check signals is a bad way of doing things
at best imho. conditions can/will change . for the tests you did should use locals
around 30- 50 miles away .to close in then you wont see much difference if any

 

[Needle Bender]

8113, what are you running for coax type & lengths? Are they exactly the same? On a Yagi the driven element is current fed, (maximum current at the center) on the Imax 5/8 the max current node is 1/4 wave down from the top, so they would be 1/2 wave out of phase at they're respective current nodes but are already 1/4 wave out of phase due to polarization, so I'd say since your SWR isn't atrocious, enjoy your increased performance!
If ever you want to feed them 'in phase' you'll need two 1/4 waves (x Velocity Factor) of 75ohm RG11 and identical 50 ohm coax, the one to the Imax 1/2 wave (x VF) shorter.
Place the 75 ohm 1/4 waves at the 2 inputs to the T, with barrell connectors to the 50 ohm from the antennas. You should have a 1:1 SWR, if your antennas are tuned resonant.
If you placed the 75 ohm 1/4 waves directly from the two antenna connectors to the T at the top, then you could use only one 50 ohm from the transmitter all the way up the tower/mast to feed both, but add a 1/2 wave (x VF) of 50 ohm between the yagi driven element and the 75 ohm to zero the phase with respect to the Imax.
Remember;
If it ain't broke, fix it till it is.
Or just enjoy the fact it's improved your performance and leave it be.

 

[Captain Kilowatt]

i am confused. It soun

something i think most missed. using dx to check signals is a bad way of doing things
at best imho. conditions can/will change . for the tests you did should use locals
around 30- 50 miles away .to close in then you wont see much difference if any

Well yes and no. An antenna that performs GREAT! for local may not be very good at all for DX especially really long haul DX where you want a very low angle of radiation. What you really need is a switch so you can switch antenna instantly and compare signals in a fraction of a second under all propagation conditions from all areas.

 

[Shockwave]

Since the coax lengths are random, how one polarization mixes with the other is not predictable. Combine this with the fact the two antennas are different and not on the same boom makes achieving circular polarization impossible. Since we don't know the phase delay through each cable you might experiment with adding different length jumpers inline with each antenna cable to see if it improves the average skywave propagation or SWR.

In the case of two antennas in the same polarization, the distance between them and the coax length will determine the directions and amount of maximum gain. Both broadside and endfire patterns are possible. With proper length coax cables the pattern can actually be completely reversed if the two cable lengths are swapped on the antennas. The same can be done by adding a small length to one existing cable.

 

[vkrules]

I can attest to the last part... especially when it comes to Australia. For whatever reason, I could always hear them, and they could hear me better on a vertical than my 4 element yagi. Propagation weirdness.

73,
Brett

Well I'm in Australia and the signals stateside are always better horizontal with the 4 el yagi even if the stateside station is vertical.

 

[Marconi]

Remember;
If it ain't broke, fix it till it is.
Or just enjoy the fact it's improved your performance and leave it be.

Needle Bender, your needle is bent.

 

[BOB MAC]

I'D LIKE TO ADD A SWITCH BOX TO THIS BUT I THINK YOU'RE RIGHT, MY AVANTI BOX WORKS FINE

I agree with the DB. What you have is pretty much a crap shoot with no technical basis whatsoever. Many many years ago I ran a Moonraker 4 with V and H polarization. I initially had them separate but in later years I combined both polarities using properly trimmed lengths of coax cable. It made a difference on some signals and not on others. Sometimes for the better and others for the worse. Propagation will favour one polarity over the other at any random time and it will NEVER favour one over the other all the time. I have seen many times a simple Imax 2000 outperform a four or five element horizontal yagi if propagation was favouring vertical at the time.