Autor Tema: YU7EF ANTENNA FOR 144MHZ  (Posjeta: 5840 )

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Offline iw2nri

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YU7EF ANTENNA FOR 144MHZ
« : 04. Veljača. 2010, 22:07:49 »
HI DR BOYS

MY INTENTION IS MADE 3 ANTENNAS 7 EL OF POPA YU7EF FOR STAKING VERTICAL

IS MY FIRST COSTRUTION OF THIS ANTENNAS I USE  AT TODAY DK7ZB

50 OHM IS VERY  GOOD SOLUTION  -NOT MATCH  -NO BALUNS-

MY QUESTION IS STACKING WITH CABLE ??? IS POSSIBOL WATH IS THE FORMULA ???

WATH TYPE  CABLE USE ???

I THINK 90 OHM AND COFIGURATIO???

THNKS TO ALL FOR MY QUESTION AND PATIENT
Ci vediamo, 144 MHz DARIO (DADO)

Offline yu7ef

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Odg: YU7EF ANTENNA FOR 144MHZ
« Odgovori #1 : 05. Veljača. 2010, 11:22:27 »
Dario

Best way to feed vertical stack of 3 yagi antennas is with 3 way 1/4 WL splitter
Attached you have drawing how to make it with four options with different material
so you can look for available material

Characteristic impedance of line is actually 86.6 Ohm so you may do it with equal
length - ODD MULTIPLE 1/4WL cable RG62 (93 Ohm) which will give reasonable and
acceptable match but you will not have 1:1 SWR

73, Popa, YU7EF


Offline 9A5AA

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Odg: YU7EF ANTENNA FOR 144MHZ
« Odgovori #2 : 05. Veljača. 2010, 11:48:56 »
Hi Dario,

29 Ω transformer can be obtained by connecting in parallel two λ/4  pieces of koaks cable with 60 Ω  impedance.
And, of course, there should be included velocity factor.
This is the same type of transformer used by DK7ZB.

Metal combiner that Popa has recommended is the best solution.

73, Dragan

Offline 9a6c

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Odg: YU7EF ANTENNA FOR 144MHZ
« Odgovori #3 : 05. Veljača. 2010, 19:32:33 »
Mi pare che con 50+75 ohm in paralello si arriva a 30 ohm che non e lontano da 28,9 ohm desiderati. Un po dio SWR non sarebbe grande sacrificio. Poi, con RG213 e RG11 siamo un po piu comodi per quanto rigarda la potenza ;) Almeno, si trovano facilmente.
Spero di non aver' sbagliato qualcosa...

Salve,

Gogo 9A6C

Offline iw2nri

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Odg: YU7EF ANTENNA FOR 144MHZ
« Odgovori #4 : 05. Veljača. 2010, 21:11:38 »
tnx POPA,DRAGAN & GOGO

 Dragan & Gogo many tnx for your respons 50+75 parallel is 30 ohm ----i dont think at this solution----

Popa  the master of Yagi tnx for splitter dettail i have the possibility of made this because i working metal for design arredaments
and is valid solution i apply this in the center of 3  yagi and i connect all with  3 identical cable rg 213 or rt 5020

solitly i work  with 100 -200 watt in portable contest because not many problem

new i have the just solution for my 3x 7 el yu7ef tnx boy

in next time i work at this proget

GOGO complimenti x l'ottimo italiano scritto ed immagino parlato

ciao ciao

Ci vediamo, 144 MHz DARIO (DADO)