Your User ID

[dnw64]

Ahh ok G6 I think I have one of them in the garage rafters need to haul it out and try it i guess would be a good antenna for the RMS station I suppose currently using an Isopole! How long is the OCFD ? I just built a HWEF 134' with a 49:1 balun works great 80-10 no tuner as well as on my MARS freq!! We use the same MA5B at the EOC here but living on the coast it gets very hard on beams so far we have rebuilt the EOC beam twice now in 5 years. My 2 meter 13B2 seems to be the only one holding up in the constant wind!

I feel like I've either slipped into a very deep rabbit hole or Google Translate is not working.

:laughing:

 

[B7510HSD]

I feel like I've either slipped into a very deep rabbit hole or Google Translate is not working.

:laughing:

No Translation Button???? :laughing:

 

[k0ua]

Ahh ok G6 I think I have one of them in the garage rafters need to haul it out and try it i guess would be a good antenna for the RMS station I suppose currently using an Isopole! How long is the OCFD ? I just built a HWEF 134' with a 49:1 balun works great 80-10 no tuner as well as on my MARS freq!! We use the same MA5B at the EOC here but living on the coast it gets very hard on beams so far we have rebuilt the EOC beam twice now in 5 years. My 2 meter 13B2 seems to be the only one holding up in the constant wind!

The OCFD is about 132 foot. With a balun designs 4:1 at the feedpoint. Height is 35 feet.

 

[k0ua]

I feel like I've either slipped into a very deep rabbit hole or Google Translate is not working.

:laughing:

Well lets see if we can help out a bit:

A G6 is an old 144 to 146 Mhz (Megahertz) antenna made by the Hustler corp. 144 to 144 Mhz is the so called "2 meter amateur band". An isopole is another ancient antenna that used to be made by a company called AEA. Now out of business as far as I know. It used a sleeve decoupling technique instead of a more traditional ground plane.

The OCFD (Off Center Fed Dipole) is just another method of feeding a dipole wire antenna. Most dipoles are fed in the center of the antenna with equal lengths of wire on either side of the feedpoint (usually but not always coaxial cable). An OCFD is not fed in the center, and is usually fed at about the 1/3 point sometimes a bit less. The reason for doing this with the addition of a 4:1 Balun which is kind of a transformer to allow usage of the antenna on multiple bands of frequencies.

The HWEF is a (Half Wave End Fed) this is taking a dipole to extremes and actually feeding it from the end instead of anywhere along it length. This requires a 49 to 1 type of transformer to transform the extremely high impedance that result when you feed a traditional dipole from the end.

MARS frequencies: MARS refers to the Military Affiliate Radio System. This is governmental program that recruits Amateur radio operators into this quasi military radio service. The frequency's that are assigned to this service fall just outside the normal Amateur radio assignment. This requires modification of the radio equipment to hit these frequencies, and often requires modifications to Amateur antennas to work (and be resonant) on these extended frequencies. We can discuss impedance and resonance in a different memo if you desire.

The MA5B is a type of Yagi antenna designed for the 20, 17, 15, 12 and 10 meter amateur bands. This is a small footprint antenna made of aluminum and is small and lightweight with modest forward gain and fair front to back ratio and front to side ratios. The aperture of the main lobe is fairly broad with the 17 meter and 12 meter portions being just a rotary dipole the aperture is around 180 degrees of course with no front to back ratio, but still good front (and back) to side ratio. We can discuss these terms like front to back and front to side and 3dB beam-widths in a separate memo if you like. I know it all seems so confusing at first, but just like eating elephants (one bite at a time) you can understand all of this if you wish by taking it in small bites and moving on into deeper understanding.

A 2 meter 13B2 is another type of 2 meter amateur band antenna, in this case a 13 element beam with excellent front to back and front to side ratio's and very good forward gain with a small aperture main lobe. In the case of the aforementioned G6 Hustler and Isopole antennas they are omni-directional antennas while the 13B2 is beam type antenna which must be aimed, and this usually implies a rotor mechanism to aim beam type antennas.

I hope this helped illuminate at least in a small way some of the confusion over these acronyms and jargon we Amateur radio operators use when we communicate to each other. I do realize each explanation just brings up more questions, but such is the way of technical knowledge.

An other example of tightening a nut on a bolt, bring ups discussions of torque wrenches and penetrating lubricants as well as possible side discussions of castle nuts and safety wire. Nothing is easy and you must start somewhere and answer subsequent follow up questions as best as you can without adding even more confusion. Ask me questions and I will give you answers as nearly as I know them.

 

[tractorshopper]

Yep. Military is where I learned to put a slash in a 0.

Yup, and I still write the date as 19 Dec 2018.

 

[ovrszd]

Yup, and I still write the date as 19 Dec 2018.

Or 20181219.

 

[Wagtail]

I feel like I've either slipped into a very deep rabbit hole or Google Translate is not working.

:laughing:

Fair dinkum cobber!

 

[ovrszd]

"Dinkum", another new one. Definition please?

 

[Wagtail]

"Dinkum", another new one. Definition please?

dinkum

INFORMAL•AUSTRALIAN/NZ
adjective
1.
(of an article or person) genuine, honest, true.
"a real dinkum bloke"
adverb
1.
really, truly, honestly.

 

[ovrszd]

dinkum

INFORMAL•AUSTRALIAN/NZ
adjective
1.
(of an article or person) genuine, honest, true.
"a real dinkum bloke"
adverb
1.
really, truly, honestly.

Thank you, I'll catalog that one!!!