Discussion in 'Amateur Radio Equipment Reviews' started by AA9ZZ, Jun 14, 2008.
I second that.
I have an R5 up now....works fine.
I was looking for a vertical to use for local ground-wave and ended up winning an eBay GAP Titan DX. The reviews show this consistently some 7 dB lower than a reference vertical over radials, which may be due to its use of a coax cable as series feed and matching network; coax is lossy. However, I had not realized it is designed as a vertical dipole and to be used without radials. When it comes in I will be experimenting to see how it compares to other antennas and how its performance might be improved.
Not wanting to put up a tower in the wife's garden, I use a Cushcraft R8 vertical. I always have good results with it, 40 through 6 meters. Perhaps it is the length of my RG11 Coaxial cable but am able to load up on 160 meters using a roller inductor tuner. It is 7 feet above the ground on a tilt down arrangement in the event of an impending storm but I do not use any radials except for the few short pieces that stick out from the bottom.
Try to think of a dipole antenna. It has a Positive half, & a Negative half.
All antennas are based on this principal. Radio Waves are Alternating Current.
Therfore, they need both the Positive & Negative sides of the dipole to propagate
properly. Your trying to match your 50-ohm output from your xcver, to a 50-ohm Ant.
Granted, thats not always the easiest chore to do! You do the math on your Freq. band, cut each side of your Dipole Ant., and adjust for minimum SWR. The same goes for any other kind of Ant. Be it a Vertical, a Horizonal Ant., or a Vertical Dipole. your in charge of getting that Ant. to be at the correct length to "POP" your RF sigs into the ether!
At that magic moment, the AC signal from your xcver reaches your Ant., & leaves the "wire" as a Radio Signal. You want it to leave at it's maximum, so it can be well recieved around the world! If your Vertical Ant. has no matching Negative Ground side, your signal out will suffer, perhaps just making a lot of wasted heat & Standing Waves!
It may work fine, but not at it's max! This gets even more critical with low wattage output, or QRP. That 5 Watts needs all the help it can get!
If your Vertical ant. has no radials at all, where is the radio wave going to go?
Sure, it may work, but not at it's best. In our Arizona winter resort, we are allowed Vertical antennas only, but no radials allowed! We utilize the metal carport awnings, as the substitute for ground radials! It works, but it's not the best answer for some bands!
The answer is to try to match the ground, (Negative), side of your Vertical to the Positive side. Do the math, cut & use several Radials for each band. Make that Ground work & do it's share of "POPPING" your radio signal out to the DX !
Even a few wires cut for the negative half, attached to the ground base would improve your antenna a lot! Most verticals are multi-band, so you would need several wires for each band you use. They can be hidden & out of sight. Having the means to tune your system would sure help. Using 3, 4, or 5 ground wires of whatever wave length your ant. is will help make the Negative side of your "dipole" Vertical Antenna work like it should! KD0QV--Jim in Iowa
Do a Google for N0LX if you fancy making a low cost vertical with small radials.
Aboard ship almost all of our mf/hf antennas are "no radial" verticals and we typically work the world. Of course, nwe have an excelent ground to work off of... What ever ocean we happen to be running through.. any quarte3r wave vertical must have that "other half".. just depends on ghow much you are willihng to cdompromise
Check this article:
Radials. They make verticals really work.
Cushcraft R5 Works Great!
Operating from South Korea, I have a Cushcraft R5 that I recently restored and mounted on top of our roof at about 33 feet at the base of the antenna. In two weeks I've worked Iceland, Russia, Netherlands, Sweden, Romania, Finland, and England. I think it is a fantastic antenna! As mentioned previously, it only uses 4 radials at the base of the antenna. I've never used an antenna with radials in the ground, so I can't give you a comparison with that type of antenna system, but this antenna seems great for the short time that I've owned it. There are a few resources on the Net concerning restoration that will help as well if you decide to purchase one that needs some repairs. Enjoy and I hope to see you on-the-air.
I have New Carolina Windom (66' wire antenna at 20' high) and GAP Eagle DX (set of verticals dipoles at 23' high). On 20m Windom performance is better on 1-2S units.
On transmit, on 40m, Windom report was 5-9, GAP was 5-5...
I use a Force 12 "Sigma 5" vertical dipole for 20/17/15/12/10m and it works great.
It's only about 10 feet tall and is ground mounted (away from buildings).