HF Vertical Antenna - Adding Gain
Вставка
- Опубліковано 29 вер 2024
- The HF Vertical Antenna is very popular, particularly where small gardens are concerned. Peter G3OJV, looks at an interesting way to add directional gain on a budget.
HPC-12 Portable antenna
www.hamradiost...
ZL3XDJ Winter Radio in New Zealand
• ZL3XDJ. winter radio c...
ZL3XDJ Channel
• ZL3XDJ/ qrp.
ZL3XDJ Channel - Recent
• ZL3XDJ . The old times .
Your Ham Radio Store
www.hamradiost...
Hello, should the reflector or director antenna be the same height as the active antenna. I am using an A99 should I use another A99?
We strive to not short the coax , how dose one short the coax stub? Shield to center?
How to keep the radials from both antennas from getting in the way of each other?
Very interesting video -- thank you!
I have a similar situation with my 6-BTV in that it's near my property line so I can't extend radials in all directions. This seems to be adding directionality, and was wondering if you've experienced the same. I'm going to see if a director will help compensate for this -- should be a fun experiment!
Hi Peter. Perhaps you could place some rotary air dryer ground sockets in the lawn at strategic places and move the reflector around more quickly. They would be unobtrusive and the unused ones would be capped.
Another suggestion - If using a tripod mount, again use a socket with a tube in it. The tripod main shaft would sit over the tube to give sideways stability in the wind. I picked up a couple of PA speaker tripods for a fiver each at a car boot
Interesting option.
Well done Peter. So glad you mentioned the shorting plug on the reflector so that the newbies won't be discouraged when their normally set up vertical reflector won't reflect. The use of the FS meter and tuning the reflector for a null is EXCELLENT! Keep up the great work OM. 73
Thanks for sharing.
I remember another way of (supposedly) getting some gain on a vertical. Back in the 1970s, they used to sell a CB (11 meters) antenna that had three verticals spaced (physically) 120° apart. By feeding all three radiators with the RF signal, only at various phase angles, you would get *CONstructive* interference in a certain direction, and *DEstructive* interference in other directions.
I think it was an early attempt at what they now call _"beamforming"_ in the cellular world.
*73 de AF6AS*
Found a use for that extra 17 foot whip that’s been packed away. Just need to figure out what i need to short the antenna to ground. Can’t wait to try it out. Thanks
Sounds great!
you have a lovely garden.
Thanks
How do you rate the 4-btv for DX on 40m Peter? I know things vary from one QTH to another, number of radials and other variables, but I am looking for something to achieve more DX contacts on 40m. For 20m up I'm happy with my fan and off centre fed dipoles, but at the height I can achieve in my garden I don't have much luck on 40m for DX (this is SSB voice). I have thought about a monoband quarter wave for 40m but that's over 10m tall, might be a bit much with neighbours. Do the traps and reduced lengths reduce performance drastically? Would be grateful for your advice. 73
I use a half size G5RV at 25ft and work ZL on Cw. I find the 4BTV is never better than the G5RV. That may be peculiar to my QTH.. DX on 40m is usually easier in Winter and using grey line times.
A diamond Quad phased array as shown in the ARRL is much better and electrically rotatable.
Not as simple or as cost effective.
To bad you didn't try FT8 or WSPR to see the difference in contacts
I use reverse beacon on CW. It’s instant! and constant.
I’ll keep my x6100
Another interesting Idea Peter, Thank you...why do we short out the entire antenna I wonder...
Remember a quarter wave vertical is half a dipole. No current can flow if the parasitic element is floating.
Remember that it’s great to get forward gain but remember it will block to some degree the signals that you don’t want to hear from the backside of the reflector. Might be worth it just to do that😊
I think most would trade gain over F/B
@@watersstanton
I have a 60 foot painters pole
Wow, you would need a steady hand!
How confusing.....A few videos ago you mentioned getting gain from the use of elevated radials and now youve reverted back to the less efficient buried radials and again you are talking about trying to find a little extra gain. Well first of all lift your ground radials up a meter or so and tack them to the fence.
Firstly not everybody has room for raised radials, and secondly you get no directivity or F/B with raised radials.
@@watersstanton of course you get directivity with raised radials what do think a vertically polarised Yagi is.....A dipole stacked against dipoles. If you are still not convinced go research the Jo Gun Antenna.
Might be worth trying to arrange the radials on the director in one direction for even more gain.
Very good. Glad you mentioned using a director also. I have built several horizontal Yagis and like using the director. I think you get more gain (not much more) with the director and it takes a shorter boom. I also want to note that if you use a self resonant parasitic element instead of one tuned lower (or higher in the case of a director) you can space them such that you get bidirectional gain. On a Yagi it’s about 5 dB over one dipole. The tuned director gives maybe just less than 6 dB and the tuned reflector maybe 5.5 dB. So you don’t lose much by going bidirectional. I did that with a couple wire Yagis I built. Worked great! I prefer a dipole as it has more gain than phased verticals but I have the room and trees to make that easy. Without the room I think that the phased verticals has a lot going for it.
73, de N4DJ