Why subscribe to my Channel? Please view and comment with your suggestions
HTML-код
- Опубликовано: 15 сен 2024
- Why you should subscribe to the channel? If you want to learn all things antennas without the math and science, here is a good place to start.
Amazon Affiliate links for these products:
Ham Radio Antenna Analysers:
NanoVNA H4: amzn.to/36uaEZl
NanoVNA Mk1: amzn.to/2VwYxUV
RUclips PC cameras I use:
Nexigo 660P - amzn.to/3ld2FUN
Papalook AF925 - amzn.to/36e4OLC
Vitade 682H - amzn.to/2JmSVKe
Tecknet (labelled AUSDOM) - amzn.to/3o4Ug7D
Canon 200D for live streaming: amzn.to/33BeOwz
Hi Justin, Thanks for your great videos. what I would love to see, is Yagi's that are fed with open feed lines. I remember in the old 1930's ARRL handbooks that open feed line was the standart for all feed lines. My dear granddad, designed his own 'rotary beam' for 20m in the 1940's, and fed this with a twin lead. This performed fantastically based on what I can read in his logbook. Later in the 1980's I convinced him to get back into the hobby. He invested in his first commercially of-the-shelf transceiver (FT101) and he re-designed the yagi he used after the war, but now fed with a 'modern' 50 Ohm line (as the TRCV was also 50 ohm). He was so disappointed that this seemed less performing, and would less easily load on bands other than what it was designed for (20m). To his feeling coax was a less friendly way to feed antennas as they absorb a lot of reflected energy, create more loss due to a 'tighter' RC circuit. So, I was wondering if open feedline beams are the answer to more flexible use of 'monobanders'. Kind regards! ON4NA
There is no design change needed, these Yagis are balanced antennas. When fed with coax (which is an unbalanced feeder) a BALanced to UNbalanced transformer is needed. Coax is convenient for modern hams as proximity to other antennas, masts etc. is it is with balanced line.
Hi Justin, Just subscribed. Can't wait to watch your videos and learn new stuff. Cheers. 73, Maximo
Look forward to answering your questions in future!
Thank you very much for contribution for ham radio. 100% agree with you. DIY or homebrewing is the ham spirit. All my antennas homebrewed. One of my most interesting part of the ham radio antenna deaign and building. I'm not tech guy. I'm medical doctor in my country and I learn hamradio each and every day. Once I found your web site with all antenna deaign, why this guy give these designs free for others. Then I realize that you have you donn't think only money. Shearing is caring. With this new youtube channel help me learn lots of new thing. Keep it up good work. Thank you very much again Justin. G0KSC de 4S6MNJ 73!
Thank you, look forward to perhaps helping you achieve your antenna design goals!
Your work are remarkable. Congratulations and thank you for sharing your knowledge here (and in your website) 73, Roberto PT2SR
Thanks and welcome
Hi Justin, it would Be great to see a video on Antenna maintenance, what cleaning products to use and things we should be checking once installed.
Thank you and what a great idea. Best scenario is one where the antenna is prepared correctly when installed in order to limit maintenance of course but definitely will include your suggestion.
Thanks for the suggestion. Best bet is the prepare your antenna correctly prior to install in order to negate the need to regular maintenance but again, this is a subject we can cover, thanks Oscar!
Can't wait to see all your new content!!
Thank you :-)
Good words justin thanks for your participation in the hobby
Hi Justin, great videos.
A video on horizontal VHF omni antennas would be good. Looking for suitable antennas for FT8 skimming on 6/4/2m only really leads to halo, omni angle and big wheels. There must be practical alternatives, maybe crossed LFA loop or something. Something that is easy to install next to a TV antenna with a couple of dbd gain would be even better.
Thanks
Mark, G6DDX.
I have not done a great deal on verticals as there is not a huge amount to be gained over what has been done already but will take a look!
Hi Justin, just suscribed to your channel but i'm a very happy owner of one of your 5 element op-des yagis.
About to try and build a 4 ele' quad and was wondering if it makes a difference if i cut 4 wires for each element instead of one. All electrically connected of course.
Many thanks for your efforts .
You have to be careful with a quad, plastic coated wire will have a velocity factor and many ham based modellers don't handle corners well.
Hi Justin, I have been using EZNEC+ v 6.0 (Not the Pro), AutoEZ.xlsm and MMANA-GL (Not the Pro). The latter is NEC2, which brings me to a request for an explanation on how to model ground radials/grids, on the ground surface or lightly buried (1-2 inches) for 1/4 wave HF. I am also using a NanoVNA, and find it very helpful if properly calibrated, and helpful if not properly calibrated. Thanks for doing this. 73 Steve W1LV
NEC4.2 has the feature for modelling with buried radials. The problem you have the the ground conductivity and the ground conditions in terms of flatness/undulations etc. and therefore, getting an exact representation of the results you will see on this basis is very difficult. Ideal, the software model is used as a means of comparison between antennas on a level playing field and then translate the best to real world in your environment. Whichever method you use (buried or above ground), as many radials as possible still applies.
Hi Justin, very interesting videos about 4nec2! I hope you could explain a bit about how to model dual band yagis. I have been able to make good dipoles (12-17) single feedline and also a 6-4m yagi in the same boom, but have been unable to achieve something interesting with 10-15m which proves I don´t know what I´m doing :-) Actually I want to model a 4el 15m + 4 or 5 el yagi 10m in the same boom, with parasitic element and single feedline or separated feedlines, doesn´t matter too much. Any help to understand the method to follow would be very good! Keep up the good work! 73! Jon EA2W
This is a good suggestion. it is a longer process which requires a lot more patience when you have multiple bands on a Yagi but it is something I can cover.
73
Justin, I plan on buying a mini quad (MQ34SR) from TGM Communications here in Canada. It has a 10.3 foot long boom and the longest element is 11.5 feet. It's going to cost me around 1200CDN by the time I get the required 1:1 balun plus coax etc. Am I wasting my money? The maker claims 6.8DBD forward gain on 20, 15 and 7DBD on 10, with 12/20 front to back and a 20DBD side rejection at 30 feet? More to the point, can I expect those numbers or close too?
Thanks: Michael DE VO1AX
Hi Justin, awesome series thanks for putting the channel together. Would you be able to include a video on metal vs fibreglass booms and elements insulated from or bonded to the booms please? thanks Mick VK2CMP
This is something for when I move to HFSS which as the ability to model booms,. insulators and coax etc, all in the same model. However, when you have such a program as I have, you then swing toward aluminium booms instead of fibreglass because you can measure the impacts of each accurately and counteract them, and most important of all, the aluminium boom is much lighter than the fibreglass version. We will cover this subject in the HFSS videos.
Hi Mick, not a great deal to do on that, no modelling required. I used for the last 2 seasons before this one, an 8el 50/70 duo with a fibreglass boom and all elements through boom. I did this and turned the boom 90 degrees in order it would not mess with the 2m Yagi which was in close proximately. Rather than bonded elements I used a single M4 bolt to secure each element and a spread washer on top. Maybe something we can look at.
Great Channel! TNX Justin. 73 Joe, DL8HCZ/CT1HZE
Thanks Joe, much apricated