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Author Topic: Analyzer Says Too Far Out  (Read 2787 times)
G8HQP
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Posts: 908




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« Reply #15 on: April 25, 2017, 11:54:22 AM »

Quote from: KD9FRQ
no choke, balun
At present you are not measuring the antenna, you are measuring the antenna plus the outside of the feeder (possibly, plus the MFJ operator too).
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VE3YF
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Posts: 581




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« Reply #16 on: April 25, 2017, 02:59:20 PM »

I borrowed an MFJ-259B analyzer.

On the two New In Bag Double Bazookas I have up, here are my numbers.

6m    50 - 3.2         52 - 2.1         53.952 - 2.9
        r20 x24 o32    r113 x0 o100   r18 x15 o25  

10m    28 - 1.3       28.8 - 1.3       29.697 - 1.5
         r48 x16 o50   r62 x12 o60     r68 x19 o62  

My Ringo Ranger shows SWR of 3.5 but I will need some work to get it down to adjust. I am trying to get a man lift so I can leave it up and adjust while in place.

So, my 10m SWR is good to transmit as a Tech.  But the 6m is way to far out. What are my viable options?  I have a Tuner I can apply to the 6m.

Is this where I need to purchase lengths of coax to give me 1/4wave multiple feed line length?

Ed:

You didn't mention which manufacture's DB you are using, but actually if you look at the IAC Website, they say that Analyzers may give false readings when testing Double Bazooka's. They also say to use your rig as the Analyzer.

http://iacantennas.com/docs/10M-DB-Install.pdf

« Last Edit: April 25, 2017, 03:08:15 PM by VE3YF » Logged

73 De Mike
VE3YF

http://www.ve3yf.com
N4AST
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Posts: 78




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« Reply #17 on: April 25, 2017, 04:07:48 PM »



Ed:

You didn't mention which manufacture's DB you are using, but actually if you look at the IAC Website, they say that Analyzers may give false readings when testing Double Bazooka's. They also say to use your rig as the Analyzer.

http://iacantennas.com/docs/10M-DB-Install.pdf


I noticed they don't give a reason why you should not use an analyzer when testing a DB.  The only reason I have found that my analyzer gave false readings were the presence of strong RF fields or the antenna was so unbalanced that common mode current caused the readings to be all over the place.
I thought the selling point of a Double Bazooka was its broad banded characteristics on 80M and 40M.  Why use one on 10M when a simple coax fed dipole will cover the entire band, not have the losses of a DB, weighs less, and is cheaper?  Not sure why anyone would be interested in a 10M Double Bazooka.

Gary N4AST
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KD9FRQ
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Posts: 355




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« Reply #18 on: April 25, 2017, 04:27:09 PM »

I noticed they don't give a reason why you should not use an analyzer when testing a DB.  The only reason I have found that my analyzer gave false readings were the presence of strong RF fields or the antenna was so unbalanced that common mode current caused the readings to be all over the place.
I thought the selling point of a Double Bazooka was its broad banded characteristics on 80M and 40M.  Why use one on 10M when a simple coax fed dipole will cover the entire band, not have the losses of a DB, weighs less, and is cheaper?  Not sure why anyone would be interested in a 10M Double Bazooka.

Gary N4AST
My reason was simple.  They were FREE.  I do not want to share the brand because I think that might be unfair to company.

I am moving to a fan dipole that has a 10m leg. The unit is not a bunch of DBs, but rather simple wire Dipoles.  Same manufacture as the DBs. I even got to visit the factory and pick up my unit to save shipping since I was driving by.

I will recheck my rig manual to see how to set the meter to SWR and see what I am getting out the DBs.  I have made no contacts in the Tech freqs so, I was wondering if I am even getting out. The tuner I have show 1.1 on 10m when set to the 10m load. So I thought I was OK.  The analyzer seems to say the 10m is OK.
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WB6BYU
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Posts: 18323




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« Reply #19 on: April 25, 2017, 06:20:47 PM »

Quote from: KD9FRQ

... The tuner I have show 1.1 on 10m when set to the 10m load. So I thought I was OK.  The analyzer seems to say the 10m is OK.



You shouldn't need a tuner on 10m given the SWR on that antenna.

However, 10m propagation has been poor recently, so it isn't very surprising that you don't hear much activity.
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W9IQ
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Posts: 3064




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« Reply #20 on: April 25, 2017, 08:59:05 PM »

Ed,

What type and length of coax are you using on these antennas?

- Glenn W9IQ
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- Glenn W9IQ

I never make a mistake. I thought I did once but I was wrong.
KD9FRQ
Member

Posts: 355




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« Reply #21 on: April 26, 2017, 04:02:33 AM »

Ed,

What type and length of coax are you using on these antennas?

- Glenn W9IQ
Both are being fed by 50ft of RG-8x I purchased from Universal.
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