70cm Quarter Wave Antenna | Great for portable use | Ham Radio | Easy to build!
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- Опубліковано 22 жов 2024
- In this video I've kept the time down to under 5 mins and easy to follow along. In the video I show you my way of building a very inexpensive and easy to build Quarter Wave antenna for 70cms - you can also change it up to suit the band you prefer.
This is my own go-to to quickly make a portable and easy to setup quarter wave for mobile/portable comms, and I've had some great results with them.
Antenna calculator used for calculations: m0ukd.com/calc...
Music by: bensound.com
All Items in the build were bought cheaply from eBay and it really doesn't take too much time from start to finish.
Build Parts:
1. SO239 chassis mount
2. M2 or M3 nuts, bolts and washers
3. 300mm welding brazing rods (I used bronze, but you can get either bronze or copper)
4. Heat shrink tubing (optional)
Any questions please feel free to ask.
Its good to see you took the 5% correction factor into consideration when making this dipole. Most people do not. For those that wonder why.....300/f(mhz) = wavelength. 300/433.500 = 0.692m = 69.2cm / 4 (quarter wavelength) = 0.173m (17.3cm) then 17.3cm x 0.95 (95% of a quarter wave i.e 5% knocked off) = 0.164m (16.4cm)
Short, sweet and enough detail to take on the build. Loved the music, too. Time for a nap ;-)
Much appreciated, thank you. 73 :)
That looks so proffessional. Heck yeah.
Got a couple of these, not quite so neat as yours though :). They hang in a tree with a handie and really effective. Thank you for sharing.
I like your neat construction ideas. Thanks for sharing.
Looking to make one, you make look easy enough for me to be able to make it. 73
They are very easy to make, honestly. And work great :) happy building!
Saw the video before I read the post, and you gave the information I needed for PMR. Many thanks 73'
Stay cool
Stay safe
Great vid. Did you do anything special to bend those so evenly?
Also, I’m assuming you deploy this in your garden, etc. Curious how high up you mount it. Was thinking about placing it on top of a slightly wider piece of PVC and routing the cable inside to a hole out the side of it. And then taking the PVC and extending it over a narrow tall telescopic pole.
Thx!
I mount it on top of a 6m pole (sotabeams tactical mini) while out portable, using a small piece of PVC pipe and the antenna sits nicely on top of it. As I only use it portable, I've not mounted it at home as a permanent fixture kind of thing. As for the bending of the radials, it was more luck than judgement! :) 73' and thanks for watching.
@@OntheMicwithMike Thanks much. Cheers from suburban Chicago. 🍺
would using wing nuts on the ring terminals be feasible? Looking for a tool less design.
What would the measurements be for a half wave? I guess just double yours?
it's almost like SO239 are made for this.. .But, I thought they start to get lossy above 100 mHZ?
Will a well designed quarter wave antenna for transmitting also be good at receiving as well? So even if using quarter wave antenna with my UBC800XLT scanner, I should consider the same design?
It all depends what you are wanting to listen to, this quarter wave is only for 70cm. For a more wider coverage for listening, you’d be better off with a discone scanner aerial.
@@OntheMicwithMike There are basically two frequencies. 459,6520 MHz and 469,6520 MHz so in general I presume it should be easy.
@@geirha75 I would make the antenna tuned for in between those frequencies, so the vertical (driven) upright antenna should be around 15cm and the radials I’d cut to size to have 17cm exposed radial.
How many watts can it handle?
an enjoyable watch sir...73
cheers Mr Phil sir! :)
Merry Christmas 🎅 🎄 ...73 M7LLA
It seems a lot of these 'vertical and 4 bent radial' designs are 5/8 wave, but I don't really know why. Why did you select quarter wave, and not 5/8 or even half wave, for example?
Being quarter wave it’s much smaller and much more discreet. If you chose to make them as half wave or 5/8 wave, the driven element and radials would need to be longer in size.
I see; so size was a primary factor. I can probably hide a fairly sizable antenna in my yard, but I'm looking for a solid monoband design for 70cm. Almost all are dual band 70cm/2M. I think maybe a vertical dipole would be the way to go.
@@arsbadmojo certainly a T2LT would be a great option if you're after a decent system that would cover a few bands. I have a T2LT I made about 18 months ago that is resonant on 10m and with a tuner I can use it on 12 and 15m too. From memory, It's possible it will tune on 17m as well. It's a great antenna for sure! Good luck with whatever you decide to go with.
@@OntheMicwithMike That's not really what I'm after; I want an antenna specifically for 70cm (444Mhz). I did see the T2LT when I was looking for 10M HF, but I'm not sure if that would translate to 70cm.
@@arsbadmojo hi, I’m looking for exactly the same thing, did you find one suitable?
Nice build instructions 👍👏👏
Thanks Mark, much appreciated. 73'