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Why interesting ? it’s been used for years on mobile competition rigs and base equipments running high kilowatts settings. Why would you buy helix for running 4 watts?

Impressive. I was planning on doing the same thing above a Mosley TA-33 Yagi, but leaving more space about 3 feet. I was asking you because when I saw your pics, I dare to say it has no more than 1 foot apart from each other and I thought they could affect each other’s performance. By the...

I’ll do as you say. I will try the LMR-400 but it’s from DX Engineering, which has a velocity factor of 84%, which gives me 15.1851’ x 4 = 60.74’ = 60’ + 9” . I would like to know how this cables from DX Engineering compare to the real deal, the Times Microwave LMR-400. Please, correct me...

I got 14.1 feet because I have a Tram RG-8X which states it has a 0.78 velocity factor. .1 is 1.2”. Some post before I said it was .82 but it is .78. I really have 14’ and 2 inches from tip to tip of each PL-259.

Bob, at 6 feet high, I get SWR of 1.1 on frequency 27,055 with R=48 and S=8. Is that close enough for resonance?

Thank for your input Bob. I wanted to test the whole system in order to discard any problems with it. Now I know it was the proximity between the yagi and the Vector. Now that I found the issue and fixed it, I’ll try again to tune the antenna where I wanted to work. Sirio states in the...

Dr_DX: Coax length from antenna to antenna switch relay box is about 30 feet. From relay box to station, another 30 feet. I noticed something. This antenna doesn’t like to be close to other antennas. When raised, the Vector’s loop get closer to a Mosley yagi on top of the tower. The longest...

By the way Marconi, I forgot to mention that before buying the Vector, I had a HyGain SPT-500 installed on the same mast going through the antenna switch, same coax, same things and I didn’t have the bandwidth issue.

Hi again Marconi. Since I had a SWR change on the roof, I did had to tune again on the roof. I was tuning for channel 20. What I am going to do is to bypass the RCS-4 remote switch and see what happens. Regarding the Gamma Match, I made sure it was centered. I incremented the Gamma Match...

Hi again. Today I could install my Sirio Vector 4000 on top of my house. It is about 12 feet above the house. House is 10 feet tall. When adjusting on the back I did it on a 10 feet tall pipe with my MFJ Analizer. Here are the readings with 14 feet of RG-8x cable with a velocity factor of 82...

Thanks guy for the info provided. But what about that if the ground wire from the roof is so long that it can act as as an unground and act as part of the antenna on the roof creating RFI issues ?

If I have a tower or mast on the roof of my house, is it necessary to ground it ? There is about 20 feet distance to my station’s ground rod.

Interesting video. Probably that will apply to endfed antennas as well.

Hi Drifter. Since you have your antennas down, how close do you have the Vector 4000 from the yagi boom ? According with the picture, it looks no more than 1 feet . Do you have any interaction between them, How is the SWR on your Vector ? Do you have any SWR readings for me to see ? How is the...

How do I do that with an MFJ analyzer?

Thanks Bob. I think I am going to use a very short coax jumper, like 2-3 feet long. But I have a question, Me, being so close to the antenna, will it affect resonance while taking readings from the analizer ? Jeje, just asking. Hey Marconi, have you modeled with Eznec something like this ?

Thanks Bob. By chance do you know the formula to calculate the coax for an exact multiple of electrical 1/4waves ?

I am using a MFJ- 269C Pro Analayzer. I don’t think it can read negative reactance. It didn’t show any + or - symbol. Just show a number.

By adding a line isolator, resonant frequency shifted down a little . For example, without isolator, SWR is 1.1 ( R=54, X= 6 ) on 27,095. With isolator, SWR is 1.2 ( R= 50, X=12) on 26,915. I want it to resonate close to channel 20 - 25. Should I shorten the last section or should I extend...

Thanks Marconi for your effort. I am going to use a MFJ or a T-4 Radio Works derrite line isolator Which one do you think would make a better isolating job ?