Coax Query...

Alan Pilot wrote:

I had my Gainmaster on the same pole and was ok but i did guy the aerial due to the strong winds we get as we overlook the Irish sea.
My pole is around the same length as yours.

Cheers Alan,I think I’ll do as you did with the Guy cables/ropes.As the bracket is 25 feet up on the side of the property and then with that 10 pole and the overall length of the antenna it’s a fair height altogether (The London air ambulance hasn’t clipped it yet..lol)
It was ok with that old Silver rod as they don’t weigh too much,but even that would still sway around when the wind picked up.What I will ask is how was your SWR on the Gainmaster Alan.

Thanks Tom
Ct4029

hi tom the gainmaster is a good choice if you buy that antenna, got mine from knights and fed with rg213,had some great contacts, don't know if you know, but its a base fed dipole so no radials needed(that's why I made this choice).sleeve through the wall is just a bit of overflow pipe.S W R great out the box and tunes 10 11 12 meters.
regards 
mark ct3433

Markone wrote:

hi tom the gainmaster is a good choice if you buy that antenna, got mine from knights and fed with rg213,had some great contacts, don't know if you know, but its a base fed dipole so no radials needed(that's why I made this choice).sleeve through the wall is just a bit of overflow pipe.S W R great out the box and tunes 10 11 12 meters.
regards 
mark ct3433

Hi Mark,That was one of the reasons getting the Gainmaster because of the lack of radials.I’ll only be using it for 11 metres and if it tunes great straight out of the box on those frequencies then it’s definitely a winner,I don’t fancy doing too much up and down getting that SWR spot on..lol

Thanks again
Tom Ct4029

It's centre fed you will see that when you get it altho it is fed at the bottom.
My SWR was from around 1to1 up to around 2 but not a problem at that.

Chickenfoot@1987 wrote:

can someone enlighten me on chokes and their uses as I saw someone on YouTube make a Dirty Balun for 27mhz ?
Thanks again Gentlemen...

If you want a bit of reading here's a good source. It also has a table of what works on what frequencies. 

http://karinya.net/g3txq/chokes/

What you can't do contrary to popular belief is just coil up a set or random length in any manner as you're actually building a tuned circuit and with ones made from coiled up coax they're narrow in bandwidth and even getting it a couple of turns out can change it from being useful to being a chocolate teapot. You can see that in the chart in the page above for the air cored ones if you look at the difference between 5 turns and 7 turns - those extra 2 turns drop the frequency it works on by 7-8MHz. 

If you want to build an air cored one which involves coiling up coax then on the chart in the page I linked to it's 5 turns of RG213 on a 4.25" diameter core. The good news is that in the UK 4.25" is almost 110mm which is the outside diameter of waste pipe you can buy from builders merchants which is dirt cheap to buy so you can use that.

Thanks Northern Crusader,
I’ll have a good read on that link with my dinner this evening.
I definitely wasn’t going to wrap coax around a few times and fix with a cable tie,If you don’t know don’t touch..lol
Thanks for you help.
Tom
CT 4029

Cheers Northern Crusader,That link was an great help and I think I know fully understand about Baluns and Air chokes.
So a quick trip to B&Q will happen this weekend.What I couldn’t read anything about was once you made the 5 turns around the pipe and everything is secured tight,Where should it be fixed.I mean do you have to keep the choke away from the Antenna or could I fix it below on the bottom T&k bracket because the Pvc pipe isn’t a conductor.
The things we do for a simple life..lol

Cheers Tom
CT4029

I just drilled 2 holes top and bottom then tie wrapped mine to the pole.

Cheers Alan,I was thinking exactly the same thing.

I am waiting for a comment saying wrong but it worked for me.
Ran mine like that until i changed aerials and put the HF multiband up with new coax and totally forgot to do a new one but didn't need it with that aerial.

I think your far from wrong Alan,I’ve seen then left laying on the ground and even screwed to the wall.The cable tie to the mast pole seems short and sweet and nice and neat..lol

Cheers.

both of my antennas run rg8x and it workes for the pmr antenna is rg8x and it does ok the A99 is the same swr on a99 is 1.3uk and mid 1.2 and all my mag mounts use rg8x and happy with the coax