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26fb99 Profile
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Accomplished DX-er
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Registered: 08-2008
Location: Stoke on Trent North Staffs
Posts: 341
Karma: 4 (+4/-0)
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2 element Cervical Quad (BBQ hombrewer)


aint got a clue about db gains,dont know the f/b ratio or any of that other stuff. dont really care but if you need to know ask john 193 [sign in to see URL] the man.
what i do know is yesterday after taking 10 mins from pulling up on the hill,putting it up and making my first qso of the day into 317 white russia 5/7 it was hammering in 1st call nearly every time to any thing i could hear which included several south american stations so its a winner.
 
my conditions were as .. yaesu875d ,100 watts ,600 ft asl in central england ,quad was 5 meters of the deck to its boom and swr for some wierd reason im not moaning about was 1.3 from [sign in to see URL] to [sign in to see URL] meg when the element spacing was extended out to 2.2 metres rather than 1.6 so i can use it on 10 [sign in to see URL] anyone can explain this.
see antennas [sign in to see URL] BBQ


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yaesu FT857d,rmkl500,wilson5,2element pubical quad(the BBq).split charger aux battery.170a truck battery,mfj 941 versatune2
100% mobile station
I got 99 Problems but a whip aint 1
Brent 26 Fox Bravo 99
73s
1/Nov/2009, 11:34 pm Link to this post Send Email to 26fb99   Send PM to 26fb99
 
John193 Profile
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Freebander
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Registered: 11-2008
Location: South Glos
Posts: 260
Karma: 3 (+3/-0)
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Re: 2 element Cervical Quad (BBQ hombrewer)


Hey dude 1.3 is super low low! quads often run a bit higher if direct fed ([sign in to see URL]). The reason the bandwidth is so good as you extend the spacing is that it reduces the mutual coupling between elements ie the further away the less influence they have on each other, which insidentally is how you tune it for highest front to back ratio. Sounds like you found that out lol. Sounds like you hd a good DX expedition on the hill m8, did u hear the russian taxis on just before the prop picked up? I laughed at your PM message Brent and I whole heartedly agree there's a couple of others i have my eye on too chap and I'm on a crusade, lol.
On the point of quad beams I dont know if you've ever been told but if you tune the second element as a director (ie shorter) then it gives more gain than as a reflector. Its worth about 1.5 dB over the normal setup but you get a crap F/B ratio but if its not important then its worth it, it is also alot closer spaced so saves boom length too. Just a thought Brent. Keep banging it out chap talk to you soon no doubt.
John
FB193
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3/Nov/2009, 5:48 pm Link to this post Send Email to John193   Send PM to John193 MSN
 
26fb99 Profile
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Accomplished DX-er
Global user

Registered: 08-2008
Location: Stoke on Trent North Staffs
Posts: 341
Karma: 4 (+4/-0)
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Re: 2 element Cervical Quad (BBQ hombrewer)


nice 1 for the info [sign in to see URL] give all your ideas a good run soon including the "tune the ref as a director".how would i go on if i simply removed the feeder from the now,driven and fixed it to the reflector?? obviously it would require a retune to be 555 tuned as its too long but the theory is there yea????.
also the co,phase both [sign in to see URL] both elements the same lengh and how do i feed the second element??what would advantages/dis ads be between my standard 2 ele quad and these other 2 ideas.
gonna give it a few good weeks blast as im tripping off the whole new world its opened up to my dxing but want a build up a good idea of my next move before i cut it up again.
taxis,commerciall radio stations,all kinds of mad !@#$ never before heard on the vert!!!!

.....keep up the [sign in to see URL].

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yaesu FT857d,rmkl500,wilson5,2element pubical quad(the BBq).split charger aux battery.170a truck battery,mfj 941 versatune2
100% mobile station
I got 99 Problems but a whip aint 1
Brent 26 Fox Bravo 99
73s
5/Nov/2009, 10:35 pm Link to this post Send Email to 26fb99   Send PM to 26fb99
 
26fb139 Profile
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DX-pert
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Registered: 01-2008
Location: Dudley west mids
Posts: 1274
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Re: 2 element Cervical Quad (BBQ hombrewer)


surely if you tune the relfecter as a driven element wont the quad raditate in two directions???
ie north & south/east west??


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139 in any GOOD group??
6/Nov/2009, 12:30 pm Link to this post Send Email to 26fb139   Send PM to 26fb139
 
John193 Profile
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Freebander
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Registered: 11-2008
Location: South Glos
Posts: 260
Karma: 3 (+3/-0)
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Re: 2 element Cervical Quad (BBQ hombrewer)


Of course it will just like any other beam. But we are going for gain and not F/B so two tight lobes give more gain than one big round one. The director as the second element will always provide more coupling hence more current flow and a tighter beam but the cost is front to back ratio. Most imperfect beams produce some signal from the back anyway hence you get stations working off the back, its just the proportions that change.
Its a trade off gain v's F/B.
Happy coupling!
193
6/Nov/2009, 12:58 pm Link to this post Send Email to John193   Send PM to John193 MSN
 


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