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Author Topic: Antenna and Amplifier  (Read 13023 times)

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Antenna and Amplifier
« on: December 21, 2007, 05:26:45 PM »
Hi All,
I just come to finish my attempts of antenna and I would like to make share this

At first, my purpose, being  Ham Radio was to make myself an outside antenna for the RB
with the assembly of one FRANKLIN

It gives the following result:

With 10 metres of cable, an antenna situated in 15 metres above the ground but
regrettably with obstacle (trees) in the East and West.

The length of cable is limit, if we increase it, we lose the gain of the antenna.

I tried coaxial like typical cable for tv satelitte and with feeder RG58U, it is has little near similar.
On the other hand it's necessary credit note of very good connectors. I had catastrophic results with a downmarket connector (especially connecting with the RB)

I added an amplifier for satelitte TV model EDA-2GR ( ELECTROLINE) bought from market and who gives a gain of 11dB.
For 10 Euro and that devoted the following result:

more information about this kind of amplifier:

it is very satisfactory.
According to attempts on a SBS-1 (made by a friend with this type of amplifier) that owed
not to work very well, but with the RB it's OK.
I think that it is a good point for the RB which accepts better in entry a large amplified signal.

An attempt with another amplifier for satellitte from CONRAD who had to look 20db of gain was a little less satisfactory but all the same very acceptable with regard to the price. (15 Euros).

In final, I bought the amplifier from KHUNE (30 dB), specific for 1090 MHz.
The result is the following one:

It is the best, because not only the coverage is enlarged, but I can also have
Flights on LFMT on the ground (with the 11dB I lost them below 90 feet).

And also have flights in approach on Marseille and Gerone (from 2000 feets),  these aeroports are more than 100 miles from home.

The price is also much more brought up as the model 11 dB!!!

We can for not expensive money, made an outside antenna with one FRANKLIN and an amplifier for satellite.
Have of the typical cable satelitte and good connectors.
With a KHUNE Amplifier it is even better, but much expensive.

Indeed on, as also written in this forum, the more the antenna is high, the more it is better kicked away that works.

A last image of my highest score with 94 planes in direct reception.



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Re: Antenna and Amplifier
« Reply #1 on: December 22, 2007, 05:22:15 PM »
Bonjour  Patrick,

Very interesting and much appreciated posting .
I have made a Franklin antenna based on the pictures you posted earlier.
Although still experimental due to te use of a 3mm dia copper wire , normally used as electrical earth wire  , that antenna is giving very good results compared to the standard RB antenna ( which is very good ). It has costed  me 1 hour of labor an less than 5 Euros to build  , coaxial cable not included . I will try to continue my experiments by adding one of those low cost amplifiers from microline.

Dan / on4aen

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Re: Antenna and Amplifier
« Reply #2 on: December 22, 2007, 05:51:49 PM »
Very good pictures there and some nice explanations. Should really help other users on deciding about which amplifiers to get and how much they increase reception. Great post :)

Have a view at our dealers page if you are interested in amplifies. They should be able to recommend one.
Contact Customer/Technical support via:
[email protected]


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Re: Antenna and Amplifier
« Reply #3 on: December 23, 2007, 03:52:58 PM »
Hi Dan, (and all!!)

Very happy that you have made a Franklin, and that there is good results.

i was a bit surprise withe the Electroline amplifier, but it's an amplifier
for cable, and the frequency is 1000 MHz, near for the 1090 MHz.

The results with standard TV amplifier for satellite are not so bad, i think it's
because the RB accept large band signal and have a good filter in imput.

we can find the electroline in Ebay.

So, the better is the KHUNE, but it's not the same price !!!

It would be interesting to know if  others people used the other models of
amplifiers and what are the results.

The next attempt will be with a yagi to try to get the lower flights towards Marseille
airport (i loose them below 2500/2000 feets).

best 73,


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Re: Antenna and Amplifier
« Reply #4 on: December 23, 2007, 08:07:26 PM »
Hi to all
A very good 9db antenna for anyone has a time for experiments showing here:
A friend has built this antenna for 1.2GHz with outstanding results. In the next days I will try to build one for my self for RB.
For any friend here not familiar with frequencies -not you Dan and Patrick :)-
the calculation mast changed from F=444 to F=1060 for the middle of RB frequency.

Something like that:
½ wavelength of coax = 300/F/2*V
Where F = Frequency in Megahertz
V = Velocity factory of Coax
300/1060/2*.66 = .09339 meters or 93 millimeters. 9cm and 3mm

¼ wavelength radiator = 300/F/4
Where F = Frequency in Megahertz
300/1060/4 = 0.070 meters or 70 millimetres

For the last calculation

¼ wavelength of tubing = 300/F/4*V
Where F = Frequency in Megahertz
V = Velocity factory of Tubing. (Use .95 for 5/16' tubing)
300/1060/4*.95 = .0672 meters or 67 millimeters



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Re: Antenna and Amplifier
« Reply #5 on: December 25, 2007, 12:50:37 PM »
Hi People,

Firts thanks to F6GSG/Patrick to share his exiting experiences.

I also dis a lot of experiences wit antenas, starting wit this one, near 3 DBS (I Think):
Very easy, very cheap, works fine !

The second one was this one recalculating the sizes to 1090.
Made one of 6 DBS (8 dipoles) and one of 9 DBs (18 dipoles)
And put all in a 40 mm PVC tube.
The short one has 1.30 Mts and the long has 2.25 mts hight.

Best wishes for all and Happy Crismas and new year. Juan