2 Meter Yagi Antenna w/ Gamma Match (Part 1/2)

Рет қаралды 126,978

Күн бұрын

Пікірлер: 30

@vk2btc 11 жыл бұрын

Hi Dave, just finished constructing your yargi using your measurements. The SWR was on the button before adjusting the gamma match, so I didn't have to touch anything, amazing.

@DaveTadlock 11 жыл бұрын

Yes, you can use a dual band antenna with a mono-band transceiver. The 2 meter wavelength sent to the antenna is longer than the 70 cm section of the antenna and it will not notice that place in the middle where 70 cm frequencies are cut off. Thanks for watching and 73.

@VinjT 11 жыл бұрын

Thank you so much Dave for the answer. Also, I'm inspired to homebrew antennas instead of buying commercial one that's why I love viewing your educational (realistic with all the faults and actions taken to overcome) videos.

@DaveTadlock 13 жыл бұрын

@matthewz07 Thank you! I am very pleased to receive such a great compliment. You are the first one for me to hear back from that has built this antenna. :)

@DaveTadlock 11 жыл бұрын

Yes. You can use a dipole driven element instead of the driven element as shown. Use an insulator to separate the two dipole halves from each other and the boom. If the insulator sticks up and the elements are not aligned then use spacers or insulators to raise the elements off the boom. The parasitic elements can be either grounded to the boom or insulated. For a simple version see also my video, "Coat Hanger 2 Meter Yagi Antenna." Thanks for watching and 73! :)

@DaveTadlock 13 жыл бұрын

@dbindner SWR readings will vary with the length of cable and with height. For a more accurate SWR reading you may use 1/2 wavelengths of cable but this is not a must for the antenna to work. Using 1/2 wavelengths allow you to adjust the antenna rather than the coax cable. I built the antenna in December and checked the SWRs indoors in the basement, about 5 feet underground, and still saw the lowest minimum SWR being at the desired operating frequency.

@radioaustralia5070 8 жыл бұрын

fantastic excellent videos . I build one of you're 40 meter inverted v antenna and it works fantastic , keep the video's coming Dave.

@robertfreeman7798 9 жыл бұрын

Hey Dave, I really enjoy your videos ! If you ever publish a book covering building antennas for all meters, I'll definitely buy it. I guess I'm old fashioned and like things in print but I have learned a lot from your videos. Thanks, Robert

@DaveTadlock 13 жыл бұрын

@matthewz07 That's great! :) I am glad to hear that you are experimenting and have made some modifications. The basic point of the video really is to demonstrate how to make the gamma match. You can use the gamma match with other yagi designs. And yes, "array" or "phased array" is correct. 73 :)

@DaveTadlock 14 жыл бұрын

The coax cable length mentioned in the video for testing the gamma match should instead be multiples of a 1/2 wave length. For 144.250 the formula for a 1/2 free space wave length is (984 / 144.250 = 6.8215' ) / 2 = 3.41075' (or about 3' 4-15/16"). If you use multiples of 3' 5" you should be close for use on 2 meter sideband.

@MrDexxa123au 9 жыл бұрын

hello dave this is vk7fggt my name is greg hobart tasmania 2m yagi works great with my th-d72 and the 70 cm yagi keep up the good work thanks 73 from vk7fggt

@chantpeace 9 жыл бұрын

Thanks for sharing your knowledge for everyone to learn and experiment. Lots of fun. Your videos are helpful and spark new ideas.

@DaveTadlock 12 жыл бұрын

Antennas for different frequencies can be mounted on the same mast. I think spacing on a mast is 1/8 wave of the highest frequency apart. The antennas won't mind multiple towers so long as the landlord or HOA doesn't mind, lol. The amateur radio antennas should not cause any major interference to the TV antenna (UHF), wireless camera (900 MHz) or wireless internet broadband router so long as you are not transmitting near those frequencies. Don't worry, you have lots of room to transmit. 73! :)

@DaveTadlock 11 жыл бұрын

Not if it has the foil shield on it. Ask a ham friend for a scrap piece of RG-8 or go buy a foot of it from a local radio shop. If you have anymore questions then please visit my website for more information about this antenna.

@BEdmonson85 7 жыл бұрын

Hey Dave, like you, I think my favorite part of the hobby is building antennas as well! I actually only own one commercial made antenna and that's because it was given to me! I have a question about the remark you made about using T6061 aluminum. What is it about 6061 that makes it better for antennas? BTW, a friend of mine just gave me an old beat up TV antenna he was gonna toss, I believe it's the same one you have in the video!

@vo1um1 10 жыл бұрын

Dave i have a 54 inch boom... if i wanted to add more elements... would continue on with the same spacing for the elements.. and same length for the gama match....

@trapperdys9157 9 жыл бұрын

Hi Dave, iwas wondering if you could help me with measurements to make this beam for 151 mhz. do I have to change the lengths of the elements of can i just move the gamma match to tune it?

@brianshelton9853 8 жыл бұрын

hi Dave I was wondering how much difference it would make if I went with a 14element hygain it is supposed to be more than 15 dB gain I got the tram 1400 it is 6db gain. I can talk farther than I can hear with 65watts I talk to mobiles a lot on simplex I can talk about 35 miles now to a good mobile my goal is to talk 50 miles to a mobile. DO you think the beam will let me do it?