Horizontal and Vertical beam running together through a T connector?

[8113 Northern MN]

Ok so yesterday I got my new 4 element yagi beam up on my tower and mounted horizontally underneath my vertical Imax 2000. I got it tuned up great with my SWR at 1.02. Last night when Australia was coming in I was having a hard time pointing the beam at them correctly. I had a T connector on the bench and decided to see what it would sound like with both antennas receiving together. To say the least i was amazed. The signal was 2-3 S units stronger then with either antenna connected alone. Without a doubt I was recieving much better. NOW, Are there any risks to Transmitting with this setup? Checking the SWRs with both antennas connected I am only reading a 1.4 at the back of the radio. Is this even an accurate reading?

Anyone ever try anything like this or have any opinion?

 

[midnight special]

just my thought,,, back in 1978 and 1979 i had a set of moonrakers 4 that i had bought used put up on a 40 foot tower,,, talked out west real easy but noticed signals coming in never changed from horz. to vert.,,, when i had installed them i had adjusted the swr seperately but when i run coax in the house i used the avanti coax switch that came with the antenna...the swr stayed the same into the switch box..... well to shorten the story some after a few years i decided i wanted to homebrew a coax switch so i opened the bottom of the avanti switch to look how it was done,,, and found out the wires that was soldered on the switch were pushed together and was shorted so that it was acting more like a t than a switch,,,after seperateing them i noticed a big difference in the horz. signal from the vert. signal....but i had used the antenna with no problem the whole time before finding the switch short...talked skip out west and north,, did what i am pretty sure one contact on ground wave over 270 miles...of course i was on top of a mountain in kentucky at the time... just a thought,,,,,,,,,,,,73 midnight special....oh by the way the avanti moonraker 4 was the best antenna i have every operated with if i could hear them they heard me,,,,,,,sad i had to move and could not use them and finally sold them....... oh and as for your signal going up with both antennas do you mean the noise level or someones signal coming in,,noise level going up doesnt mean recieveing better just means getting more interference...

 

[8113 Northern MN]

The receive was better as far as peoples Signal.....I did some reading and decided to try it out and some of the guys I talk to constantly reported that with both connected through a T I am also sounding better then usual. I pulled someone down to 36 and tried each antenna by itself with the beam pointed at him (in Florida) and then with them both connected through the T connector and was told both together was a louder sound on their end. Others who heard us QSY followed and also reported it as being better. Everything I have been reading claims that the signal leaves the antennas in a "circular pattern" and is very feasible. Apparently I lose some of the gain that is possible with the Beam...but so far through my tests I am very happy.

 

[The DB]

Everything I have been reading claims that the signal leaves the antennas in a "circular pattern" and is very feasible. Apparently I lose some of the gain that is possible with the Beam...but so far through my tests I am very happy.

If all you have is a T connector between the antennas then you do not have circular polarization. To get that you would need a 90 degree phase delay line. You would also need the antenna in a + or a x configuration, so if you have an Imax above a 4 element horizontal dipole (what I think your setup above describes) you cannot have circular polarization. Also, if you have circular polarization, then anyone who is using a single vertical or horizontal element will receive effectively 50% of the signal that they would get from an antenna you have with the same polarization.

To determine what is happening with your setup I would need to actually take a loot at your setup. If connecting them together with a simple T adapter makes that much of a difference for the better, then you likely have a problem with one or both antennas to begin with and connecting them together inadvertently resolves this issue somehow. Several possibilities come to mind.

My first suggestion would be to add a good choke to the feedpoint of each antenna if you haven't already. A coaxial choke built to proper dimensions is fine. Test each antenna separately this way, then test them together, still going through the coaxial chokes. See what happens then.


The DB

 

[8113 Northern MN]

Im running a Imax 2000 vertical with a Syrio SY27-4 mounted below it horizontally. Both antennas have their own coax coming down and meeting with a T connector behind the radio.

 

[Captain Kilowatt]

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.

 

[Robb]

Get a decent antenna switch so that you can switch between the Sirio and the Imax.

Amazon product ASIN B00J5RB9C2

 

[RatsoW8]

CK and The DB are correct. If anything both antennas are probably not performing as well as they could runing seperately. Any improvement reports you are getting are the result of propagation changes and probably nothing else. The best thing to do is follow Robbs advise and get the switch. You'll be surprised how signals and polarization change during a QSO with a distant station.

 

[Marconi]

Ok so yesterday I got my new 4 element yagi beam up on my tower and mounted horizontally underneath my vertical Imax 2000. I got it tuned up great with my SWR at 1.02. Last night when Australia was coming in I was having a hard time pointing the beam at them correctly. I had a T connector on the bench and decided to see what it would sound like with both antennas receiving together. To say the least i was amazed. The signal was 2-3 S units stronger then with either antenna connected alone. Without a doubt I was recieving much better. NOW, Are there any risks to Transmitting with this setup? Checking the SWRs with both antennas connected I am only reading a 1.4 at the back of the radio. Is this even an accurate reading?

Anyone ever try anything like this or have any opinion?

8113, here is a video I did using a switch box and a T-connector with two verticals. It does not indicate exactly what you were doing, but maybe you will see something interesting. I did this at the request of our member Shockwave, an administrator on this forum.

 

[2RT307]

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.

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

 

[Robb]

8113, if you run both antennas together in phase at the same time, you will only hurt your TX because there will be phase cancellations/nulls coming right off your antenna. This is why there is talk of a phasing line, so the waves will be in phase - rather that being mixed as you now have it. Without a phasing line, you are doing more bad than good.

I had to help out a local op that thought as you did, that somehow two antennas would work better than one. Trying to explain to him the dynamics of why it wouldn't work and what was happening was useless. We learn by experimentation. Can you understand why it won't bring about the desired effect of circular polarization?

Let's say you installed a phasing line. It still wouldn't be better off, as the vertical and horizontal antennas aren't physically the same and therefore will not react the same. In the final analysis, you would be far better off with an antenna switch and use it to hear which polarity is receiving a given signal best.

Now, if you were doing this with a Moonraker IV and had a phasing line between the vertical and horizontal drive elements as CK did; then that would be a different story . . .

 

[Captain Kilowatt]

8113, if you run both antennas together in phase at the same time, you will only hurt your TX because there will be phase cancellations/nulls coming right off your antenna.

phase cancellations/nulls coming right off your antenna Could you explain that one too me Robb? I always thought the transmitter would be harmed by excessive SWR caused by an improper impedance presented by combining two or more antennas that had a resulting impedance far removed from 50 ohms. I had no idea that phase cancellations or nulls coming right off the antenna caused it. Stupid me thought he would be fine with the 1.4:1 SWR he had with the two combined, at least as far as damage goes.

This is why there is talk of a phasing line, so the waves will be in phase - rather that being mixed as you now have it. Without a phasing line, you are doing more bad than good.

Yes the antennas need to be fed in the proper phase but it has nothing to do with SWR or impedances. It has everything to do with making sure the signals from each antenna reinforce each other in the areas that they are supposed too and cancel in the other places that they are supposed too.

 

[Robb]

Didn't mention SWR once; but I see your point.

The op in my area that did this had a loss of more that a few S-units loss in TXing at my end; so I did assume that there was cancelling happening. Yes, I assumed; bad choice of word - I know.

 

[Captain Kilowatt]

Didn't mention SWR once; but I see your point.

And THAT was MY point.

 

[Marconi]

Just to let you guys know a little more about this video above.

I was comparing signals with Tim, 55 miles due North of me. My two verticals were mounted North and South...so they were in line with Tim and not on the broadside of the signal.

I did these videos and at this time I was calling for another buddy that is due West of me...hoping to compare the broad side signals, but he was in and out before I could do any switching.

I used the antenna feed lines at the TX end to connect to the T-connector, so the lines were in no way tuned and this was not a good co-phase comparison. I was just trying to test the idea that Shockwave suggested.

My Marconi antenna is made with 3 x 102" whips mounted in an A-99 ground plane hub, and 1 x 102" whip in a mobile L-bracket on the mast. The Marconi below has 7 radials, but it will give you the idea what it looks like...a Starduster.