-
You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
where to buy qubical quad spiders
- Thread starter wahlrite
- Start date
Are you looking for something to buy, or designs so you can make one/them? Not having the ability, or the equipment to make them, I'm in the position of finding a commercial source that works.
One solution is to do a lot of checking to see what's been around for a while, is still in use and being produced, and typically from a well known antenna manufacturer.
One of the first things people have to get into their head is that a 'quad' is not a 'small' antenna. It's fairly large depending on the band, and that means heavy duty'er depending on weather, etc. All that 'bigger' stuff starts in the ground and goes all the way to the top if it! The 'quad' it's self is probably the cheapest part of the whole mess.
- 'Doc
One solution is to do a lot of checking to see what's been around for a while, is still in use and being produced, and typically from a well known antenna manufacturer.
One of the first things people have to get into their head is that a 'quad' is not a 'small' antenna. It's fairly large depending on the band, and that means heavy duty'er depending on weather, etc. All that 'bigger' stuff starts in the ground and goes all the way to the top if it! The 'quad' it's self is probably the cheapest part of the whole mess.
- 'Doc
Hey Doc, thanks.
I'm actually looking to build one, 4 actually, I want to build a 4 element quad, but I cant seem to find anything to look at except the old moonraker hub design. The next question would be, if their is not anyone making these maybe I should consider building them and selling them, what do you think,
Rick
I'm actually looking to build one, 4 actually, I want to build a 4 element quad, but I cant seem to find anything to look at except the old moonraker hub design. The next question would be, if their is not anyone making these maybe I should consider building them and selling them, what do you think,
Rick
Rick,
Feel like making and selling them? Hey, knock yourself out with it!
It's basically a mechanical thing, not particularly electrical at all. Using a 'steel/aluminum' design would probably be the cheapest way out. Lot's of exotic stuff you -could- make them out of, but then that get's into the 'practical a$pects', you know? Then you get to "jig-up" to build them! If you have experience in doing that sort of thing then it shouldn't be absolutely impossible. Just work.
Four or five years after you get into full production, I'll take a few! (I can just see you waiting with 'baited' breath, right? Sorry, couldn't resist.)
Good luck with it!
- 'Doc
Feel like making and selling them? Hey, knock yourself out with it!
It's basically a mechanical thing, not particularly electrical at all. Using a 'steel/aluminum' design would probably be the cheapest way out. Lot's of exotic stuff you -could- make them out of, but then that get's into the 'practical a$pects', you know? Then you get to "jig-up" to build them! If you have experience in doing that sort of thing then it shouldn't be absolutely impossible. Just work.
Four or five years after you get into full production, I'll take a few! (I can just see you waiting with 'baited' breath, right? Sorry, couldn't resist.)
Good luck with it!
- 'Doc
Rick,
You can look on QTH classifieds and in the antenna section there is a manufacture out of GA I think that sells the hubs for the quads, 3" with reducers down to 2" boom size.
I purchased four of them and built a four element quad for 11 meters, it was a monster, worked great 15 feet off the ground on the test tower.
NO way in heck was I ever going to try and put that heavy beast up a tower, so I settled for a two element and it works great.
As Doc said it is a mechanical thing, the other consideration is not "IF" the quad comes apart once it is up in the air, it is "WHEN" it comes apart, and it will come apart in bad weather.
With that said they are a heck of an antenna, work great and all that stuff, so have fun with it, just keep in mind everythng is heavy duty from the ground up as Doc allready mentioned to you.
You can look on QTH classifieds and in the antenna section there is a manufacture out of GA I think that sells the hubs for the quads, 3" with reducers down to 2" boom size.
I purchased four of them and built a four element quad for 11 meters, it was a monster, worked great 15 feet off the ground on the test tower.
NO way in heck was I ever going to try and put that heavy beast up a tower, so I settled for a two element and it works great.
As Doc said it is a mechanical thing, the other consideration is not "IF" the quad comes apart once it is up in the air, it is "WHEN" it comes apart, and it will come apart in bad weather.
With that said they are a heck of an antenna, work great and all that stuff, so have fun with it, just keep in mind everythng is heavy duty from the ground up as Doc allready mentioned to you.
Looks great,
impedance on a four elemetn should be around 50 ohms, two element is around 100 ohms
If you decide on a two element then a piece of 75 owm coax 1/4wl with velocity factor figured in will make a good match to 100 ohm feed point
Have fun[
QUOTE=wahlrite;233217]well here ya go, what do ya think, had some fiberglass tube that I made work, now I guess I need to come up with a unun to get from 100 ohm to 50 ohm.
[/QUOTE]
impedance on a four elemetn should be around 50 ohms, two element is around 100 ohms
If you decide on a two element then a piece of 75 owm coax 1/4wl with velocity factor figured in will make a good match to 100 ohm feed point
Have fun[
QUOTE=wahlrite;233217]well here ya go, what do ya think, had some fiberglass tube that I made work, now I guess I need to come up with a unun to get from 100 ohm to 50 ohm.
I had to make my matching sections 3/4 wavelengths long for 10 and 12 meters. With my long boom, the 1/4 wl would have been too short to rotate the quad. I used RG-11 and it works out just right. For 15/17/20, the 1/4 wl sections are fine.
Hey wavrider,
with what type of equipment did u measure ohms on your quad?
all of the stuff on the web i have been reading says that the more elements i ad the higher the ohms will be, I have a mfj analiser which i plan on using, I hate trying to learn from the web, one never knows if the info is correct or not.
what size and how many eliments did you have? what do you think of the piece I made?
what do you think the retail price should be?
thanks, Rick
with what type of equipment did u measure ohms on your quad?
all of the stuff on the web i have been reading says that the more elements i ad the higher the ohms will be, I have a mfj analiser which i plan on using, I hate trying to learn from the web, one never knows if the info is correct or not.
what size and how many eliments did you have? what do you think of the piece I made?
what do you think the retail price should be?
thanks, Rick
As more elements are added, the driving impedance goes DOWN. It is not unusual for a multi-element beam to have a driving impedance of only 15-20 ohms. Of course there is more to it then simply the number of elements like spacing etc.
- No one is chatting at the moment.
-
-
dxBot:63Sprint has left the room.
-
dxBot:kennyjames 0151 has left the room.
-
-