has anybody tried a "Balun Kit"

[GnG8d]

I'm only running 2kw now, but I want some "headroom"?

Anyway, the 170' roll of heliax was in fact because of loss.... and "headroom" =) because to get where I want, I have to run out the 2nd story of the house, up a hill and then up the tower. I figure 150', but I bought 170'. I've got the tower, hinge plate, cables and pulleys to stand an 80' tower which will get me somewhat level with surrounding ridges. I'm still looking for the 30' telephone pole however.

So, I have no real problems with neighbors per se (one is within 100 yards), but I do want to keep all RF at the antenna and not in the shack ........... which is why I was looking at the Palomar Engineers thinga ma bob. I know it says "up to 1/2"" and might be tight on the hardline, but I'm a machinist by trade, so I can dust a few thousandths out if need be.

 

[Moleculo]

You might want to think about something like this:

 

[GnG8d]

I was looking at THIS, but doggone it, from all accounts a 1:1 balun IS a choke for CMC and people want to split hairs saying that a choke is NOT a balun and a balun is not a choke.

I know Beetle says a choke is not a balun and a balun is not a choke, and I know that I like what Beetle has to say in general, but jeez, from all accounts and research a 1:1 balun IS a choke ............. I think I'm fixin to just put it up without any voodoo, see what it does, even though getting it up/down is going to be tougher than a weekend in jail. The wife has no problem with RFI, but I just don't want it if it can be avoided.

 

[RickC.]

Question-- how do you plan to support the weight of the hardline at the quad's feedpoint? Do you plan to build it in a diamond configuration and attach the feedline to the crossarm?



Rick

 

[GnG8d]

Question-- how do you plan to support the weight of the hardline at the quad's feedpoint? Do you plan to build it in a diamond configuration and attach the feedline to the crossarm?



Rick

Yeah, I figured I'd come up the mast and across the boom, then down the spreader to the feed point.

 

[RickC.]

Right, that's what I was going to suggest if your spreaders are stout enough to handle the 1/2" line. I think what you're finding is what's common in rolling your own: Physical needs dictating what you use. There's no doubt a toroidal balun in a "can" would work fine electrically, but dealing with wire loops can make you step back and scratch your head sometimes as far as supporting the feedpoint and eliminating sag.

What do you expect your feedpoint impedance to be? If you're planning to use a 75 ohm Q section those ferrite beads would fit over RG-11 just fine. The instructions mentioned greasing the jacket of the feedline to get the beads to fit but I had no problems slipping them onto RG-213.

I'm speaking only for myself here, but I've built quite a few quads and delta loops over the years, using baluns, coax feed with Q sections, and wire gamma matches. Guess what-- they all worked and I honestly could not tell any difference in the operation of any of them other than the Q section matching being a bit more broad-banded than the gamma.

The dualband yagi I just built has not seen much use since it went up due to me just starting my own business and not having much time for radio (hopefully that will change in a couple of weeks), but the ferrite bead choke balun appears to be working fine. I moved the shack upstairs to another room in the house which has 1962 2-wire AC and I have not grounded anything yet. Even with that I saw no problems with RFI or RF feedback when running the amp.

I think you'll be OK if you use the palomar kit.

Good luck,


Rick

 

[GnG8d]

Thanks Rick for a great reply

 

[GnG8d]

What do you expect your feedpoint impedance to be? If you're planning to use a 75 ohm Q section those ferrite beads would fit over RG-11 just fine. The instructions mentioned greasing the jacket of the feedline to get the beads to fit but I had no problems slipping them onto RG-213.

BTW, I'm expecting it to tune out to 50 ohm. I was expecting to use a 75 ohm Q section, but after tearing into the box and RTFM (CptKW) there is no mention of using one. It only mentions the feedline and terminal block pictured above.