TONNA 20438 antenna UHF F9FT cross 2X19 ele. antenna discussion

Ελληνικά πιο κάτω

TONNA PART No 20438
UHF 2X19 ele. antenna

Now i have some problems to solve that is dedicated especially to this TONNA 20438 antenna  UHF F9FT  cross 2X 19 ele antenna.
A.
1. Why  TONNA didn't support X on this 2X19 UHF antenna ?2. Why it has coaxial N-type female driven elem. connector while in the manual has two terminals,

3. Why does not have a BALOON  like any other tonna ?
 
4. Is it the tip of the coaxial N-type female driven elem. connector to the inner conductor in the closed dipole ?

5. Why coaxial N-type female driven elem. connectors  looks to the center. When going through a bugle cable isn't affect antenna ?

B
1. This antenna, is not like the VHF cross TONNA's antenna part No 29818 (remind that at new TONNAs added number TWO (2) in front of the old part Nrs)
they DO NOT NEED matcing-stub 50 ohms coax
 Phisically constracted the delay by distance 1/4 λ the other polarization antenna aray on the same boom laying.
to make RHCP & LHCP  at the UHF you do not need to add matcing stub 50Ω .
Only T mach with two equal coax feeding lines 75 ohm λ/4 - VF

2 . Always the RHCP (or LHCP) polarization is recognisable by looking the "antenna" from the front side. Usually instruction are given looking antenna from the back but don't mess it. 

3 Now the problem is to change from RHCP to LHCP. This can be done changing the feeding on the second aray from left to the right  when you are looking antenna from the back . Thus just changing  shield with inner conductor in the same length coax.  the problem is to not prolong the one from other feeding coaxial 75 ohms

4. having divider i must find a way to make this polarization change? resolving
at the same time and the problem Νο 3 . fig 2

5. Why the tonna antenna bracket is not constructed for X setting ???

More fudtamental information on sat. antennas can be found on the website from SV1BSX, the article he wrote is a great source of information if you want to learn more about polarization. Unfortunately he is SK but we keep his site alive.

ΠΡΟΒΛΗΜΑΤΑ  ΜΕ ΤΙΣ ΔΟΡΥΦΟΡΙΚΕΣ ΚΕΡΑΙΕΣ ΤΟΝΝΑ ΤΩΝ 70 ΕΚΑΤΟΣΤΩΝ UHF  2X19

Γιατι ο ΤΟΝΝΑ δεν εκανε στηριξη Χ σε αυτη την δορυφορική κεραία ;
Γιατι εχει ομοαξωνική υποδοχη ενω στο εγχειριδιο εχει δυο ακροδέκτες,
Γιατι δεν εχει υποδοχη BALOON όπως σε ολες τις άλλες? 
Γιατι δεν εχει καλή στηριξη η δαγκανα ?
Ειναι το tip signal της υποδοχης κονέκτορα  το κεντρικο στο κλειστό διπολο ?
Γιατι βαζει να κοιτουν οι κονεκτορες προς το κεντρο.  Οταν θα περασει ενα καλο καλωδιο δεν θα επιδρά στον συντονισμό ?

Ολα αυτα καλούμαι να τα λύσω και να παραγω καλά πρακτικά αποτελέσματα από αυτες τις κεραίες.

Με υπομονη μελέτη αλλά και με αναγωγες στην θεωρια, θα προσπαθησουμε να απορρίψουμε τα  "ψέματα του Διαδικτίου" και να δουλέψουμε τις κεραίες σωστά.
   
μερικες εικονες παρακάτω

GRC-109

this radio introduced as a spy set.
It was “The Jeep of the radio world” as dubbed by a former Special Forces radio operator in Vietnam

They were used extensively from the early 1950’s (as the RS-1) through the 1970’s and beyond by the CIA, Special Forces, other US military and allied units worldwide.

transmitter output of between 10 – 15 watts, a built in key that works well, versatile power supply options and a sensitive receiver, they did the job.  The transmitter covered the frequency range of 3 to 22 MC in 4 bands; the receiver covered 3 to 24 MC in 4 bands.

 History of the GRC-109 [See the similar historical information under the RS-1 section.]
The GRC-109 started production about 1961. Compared to the RS-1, GRC-109 units have more date-coded components, and more documentation is available to support those dates. GRC-109A units have a 1969 contract date on the ID plate.
In late 1961, the CIA organized a number of 12-man Special Forces teams to work with Montagnard tribesmen, and used the RS-1 for communications. Meanwhile, the Army's chief signal officer arranged for the RS-1 to be adopted for military use and renamed the GRC-109. Even though the Army had many RS-1 sets in use already, giving it an Army identifier would have simplified logistics. By late 1962, the Special Forces team network had 24 stations. The GRC-109 set in each "A detachment" SF camp was kept in a sandbagged bunker, with several antennas installed. The antennas were a target of Viet Cong raids, but for emergencies, they found that a longwire buried 18" underground in bamboo pipes could be used. [Ref. 6]
The GRC-109 became a standard issue radio to all combat units in forward areas after 1965. It was included in the inventory of all fire bases, and was at least used as a backup radio. Even though Special Forces had access to the latest high-tech radios, by the mid-1970's many units had adopted the GRC-109 as their primary long-range radio. It was rugged, reliable, and maintainable in the field, and offered several power supply options. The newer radios tended to require specialized batteries which were often not available in the field.
Estimated dates are summarized as follows:

·         RS-1: 1950-1964 (RT-3 #6487, a late-production unit, has apparently-original tubes dated early 1964).

·         GRC-109: 1961-1969 (PP-2685 #88 has parts dated 1961).

·         GRC-109A: 1969-1973 (units have a 1969 contract date).

GRC-109 notes from John Liner:

[Regarding reliability:] I never had a 109 fail to function. I was always able to communicate and send my traffic through with it. I operated in many different locations, including an A camp in Viet Nam, the forests in southern Germany, and out of apartment buildings in downtown West Berlin.

[Regarding the apartment building use:] I used the big power supply that is part of the GRC-109 kit [PP-2684]. The antenna was a broomstick with about 50-75 feet of wire wound on it, with another 10 feet trailing off the end. The coil of wire sort of made the antenna look electrically longer. I placed the broomstick in a window and let the wire dangle out of it. Other guys have used stairwell banisters for antennas. For a ground I just ran a wire to the radiator in the room (most old German pre-war apartments had steam heat).

GRC-109 notes from Don Valentine:

We had small dry batteries for the AN/GRC-109 receiver so we wouldn't have to crank that %$#@%$# generator to send and receive messages. I never saw a PA-109 while I was in SF. Apparently, it was only for transmitting and the operator had to have a dry cell battery for the receiver or have the team gorilla crank that &%$@#$ generator.

The 109 was very forgiving if you didn't erect a by-the-book antenna. When in Laos, I communicated from Luang Prabang to Vietiane using a coat hanger. It would even load a military vehicle, wire clothes line, or barbwire fence and use that for an antenna.

The AN/PRC-74 replaced the GRC-109 on the SFODs in the mid-60s, except for the A Camps in Vietnam. We helped test the proto-types while we were assigned to Project Delta [Det. B-52, 5th SFGA] in Vietnam. The proto-types were called HC-162s

TONNA 20438 antenna UHF F9FT cross 2X19 ele. antenna discussion

TONNA PART No 20438

UHF 2X19 ele. antenna

Now i have some problems to solve that is dedicated especially to this TONNA 20438 antenna  UHF F9FT  cross 2X 19 ele antenna.
1. This antenna, is not like the VHF cross TONNA's antenna part No 29818 (remind that at new TONNAs added number TWO (2) in front of the old part Nrs)
they DO NOT NEED matcing-stub 50 ohms coax
 Phisically constracted the delay by distance 1/4 λ the other polarization antenna aray on the same boom laying.
to make RHCP & LHCP  at the UHF you do not need to add matcing stub 50Ω .
Only T mach with two equal coax feeding lines 75 ohm λ/4 - VF  (fig 1)

2 . Always the RHCP (or LHCP) polarization is recognisable by looking the "antenna" from the front side. Usually instruction are given looking antenna from the back but don't mess it. 

3 Now the problem is to change from RHCP to LHCP. This can be done changing the feeding on the second aray from left to the right  when you are looking antenna from the back . Thus just changing  shield with inner conductor in the same length coax.  the problem is to not prolong the one from other feeding coaxial 75 ohms

4. When you have the power divider must find a way to make this polarization change? resolving
at the same time and the problem Νο 3 . fig 2

5. Why the antenna bracket is not constructed for X setting ???

More fudtamental information on sat. antennas can be found on the website from SV1BSX, the article he wrote is a great source of information if you want to learn more about polarization. Unfortunately he is SK but we keep his site alive.





fig 1

fig2

fig3

Setting up new Satellite Set

this is the solution for the No 4 question

fig 2

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Long wire muching

Portable Satellite Antenna Base

 an old setting