Anyone tried the Sirio re-issued Starduster 11M / 10M Antenna? Just ordered one.

[ThaDood]

I was trying to build a better, lower-gain, antenna for 11M CB and 10M local Chit-Chat, that goes on in my area on 28.415MHz USB. Being in this valley bottom, low-gain antennas seem to be the best way on VHF / UHF to talk out of here. Currently, I'm using a free Cushcraft AR-10 10M 1/2-Wave GND-Plane, which does pretty good, at +2dbd gain, but I believe that I could do better in my geographically challenged areas to my South and East. Anyway, by the time I get the parts together, and the time to do it, I might as well pay for an old tried & true antenna that the Italian company Sirio has re-issued, the old antenna design from Antenna Specialist, The Starduster.  https://www.sirioantenne.it/en/products/hf/starduster-m-400   I ordered mine from Copper Electronics.   https://www.copperelectronics.com/cart/M400-10-11-Meter Thus far, I've had good luck with them and they still have my INFO. So, an antenna that was all-the-rage in the late 70's and early 1980's with the CB'ers of the time. Quite a few friends of mine, back then, had one and loved them. So, a pretty Unity-Gain, 1/4-Wave, antenna for the upper HF band, with a higher angle of radiation, to take better advantage of Knife-Edge-Refraction and even Sporadic E propagation. The down-side that I've observed of this original antenna is that it may easily brake in wind storms. However, they seemed to be easily repairable and most were put back up. So, I have to ask, have any of you tried the 'ol Starduster, or even the newer Sirio version? What do you think? 

[ChrisSmolinski]

I have not tried that antenna, but I have a Sirio discone, and have been very happy with it - good quality.

[TRI International]

It seems to work fine for me it is my primary antenna. I've been using this for the last few years so it should do the job for you.

[RobRich]

Sirio construction quality in general seems okay from what I have seen. As you noted it is lower gain since it effectively has no appreciable gain.

While your Cushcraft AR10 is an end-fed half-wave vertical that has more gain on the horizon assuming both are mounted at appreciable heights, I doubt you will note much difference either way. Gain numbers even when not (typically) exaggerated by manufacturers often assume proper height, near perfect installation, no nearby objects, no common mode, etc. YMMV, of course.

I have a Shakespeare 318-GBT 18' vertical grounded mounted over eight 9' on-ground radials. I do not care much about local contacts, so it is a different situation for me, but the setup has proven quite effective for DX on 11m SSB.

[ThaDood]

Finally, returning back to gave y'all my take on the Sirio Starduster make-shift 1/4-wave GND-Plane. And??? It's seems the perfect Upper HF Antenna for my near bottom valley location. 2:1 VSWR curves are from 25MHz to 30MHz! The 1st, 1/2-ass installation was placed 30-some feet away from the house. The Cushcraft AR-10 is side-mounted to the house and RX's all the house's electrical & computer noisy garbage. Noise, on the AR-10 is anyway from S3 to S5 of hash & BZZZZZZZZ. Noise, on the Starduster is anywhere from 1/2 an 'S' unit to S1. (Nice!!!) 1st Starduster install, the GND Radials were only 10ft off the ground. VSWR sweet-spot was 1.3:1 around CB Channel 20. 10M local Chit-Chat FREQ here is 28.415MHz USB. VSWR was just under 1.6:1. (BTW, I went by the Sirio manual for elements' lengthening & settings.) Certainly usable to talk, but a touch of a tuner is good to do. Anyway, folks on CB and 10M Chit-Chat gave me mixed reviews. Some CB'er noticed that I was down in signal, and the dude that I QSO with on 10M, about 20-some miles away in Culloden, WV, said my signal was down a couple of S-units. However, some CB'ers also noticed a signal improvement a couple of "S" units, over the AR-10, in other directions. One thing that was noticed was the RX improvement in WWV's 25MHz signal in the daytime. At least several "S" units over the AR-10, and even my Windom Antenna. During Christmas, the Starduster worked great on Sporadic "E" catches, with just 20W. And, 1st time shout & catch. I was strongly encouraged, by my friend in Culloden, to raise that Starduster higher. So, before that cold-snap in January, I had a 50-some degree weekend to lower, retune the Starduster, by reducing the VERT length a few inches, and added another 5ft pipe section to the mast. WOW!!!! Just that added 5ft raise made an S3 improvement to my friend in Culloden. And, VSWR on 28.415MHz, now 1.2:1. (No tuner required there, and the GND-Radials may have been too low previously. Thus, a capacitive effect.) On 10M the rig is a MAX-out 20W Xiegu G90, and the CB is a Uniden Bearcat SSB980, totally bear foot. CB Band VSWR is 1.3:1 on CH40 and 1.4:1 VSWR on CH1. (That's fine.) Antenna does hear well on 12M, (24.9MHz.), but at a 2.1:1, I need to tweak the tuner there. And, 3:1VSWR on 15M, 21MHz, where a tuner is fine there as well. The auto-tuner will do 20M, 14MHz, but I've noticed that my Windom is far better there. So, still testing this antenna, as time allows, but so far, I'm really diggin' it. https://www.copperelectronics.com/cart/Antennas-Towers/CB-Antennas/Base-CB-Antennas/M400-10-11-Meter       

[Robot Matrix]

I'm thinking of building a vertical dipole for 10/11m, possibly with capacity hats at both ends for better bandwidth. Having never built one,  I can't attest to the claims I've read... but I've read you don't need radials if the feedpoint is at the proper height, the takeoff angle is low for DX, and if using hats the physical length of the antenna will be shorter. Have you tried anything like this?

[ThaDood]

Um, sort of... My 1st good CB antenna, back in the early 1980's, was my Uncle's late 1960's Hygain Super Penetrator. https://www.k5rwk.org/2022/08/25/the-super-penetrator-a-beast-on-10-meters/  It, had four, top-mounted on the VERT Radiator, 45-degree, 10" aluminum rods, for a capacity hat. Those kept falling off, and my CB performance didn't seem to change without those. Also, if you look at the VERT radiator on the Starduster 1/4-wave GND-Plane, about 1/2-way up the VERT Radiator, are three 5" 45 degree rods. What are those for? I would assume as a CAP hat of some type. Click-on the icon image from this link to see that. https://sirio.store/index.php?main_page=product_info&products_id=26  Now, where a capacitive top does make a big difference is on a Medium Wave, Part 15, 3 meter long, antenna.  Yeah... 10ft isn't very efficient at like a calculated .025%. If you see those TIS AM stations, they have huge, like 10ft diameter, tophats on them. Question is, does this answer your question? Um, I don't think that it really does. Hmmmmmmmmmmmm...

[Robot Matrix]

I'll have to look in to all that. Meanwhile, the 25-30MHz SWR curve you mentioned seems pretty impressive. Pretty sure the last 10m antenna I built was part of a fan dipole, but it definitely didn't have the bandwidth to cover 11m as well.

I can't imagine a vertical dipole alone, without capacity hats on both ends, would be any different with the bandwidth, but I only mentioned it because you mentioned talking to locals... which most of them would probably be running verticals. I was just tossing it out there.

But sounds like you got something pretty good for your purposes.

[RobRich]

Often one get away with no radials on an end-fed halfwave like many of the popular ~18' CB/10m verticals. The RF path for the "other side" of the antenna tends to be common-mode on the coax. Kirchhoff's current law applies even to end-fed antennas. For some deployments it can work fine, while others might incur common-mode noise and/or RF feedback, thus why many recommend short RF ground radials at the feedpoint and/or a common-mode choke like an 1/8 wave down the coax from the antenna feedpoint.

My 18' end-fed vertical is mounted over 8x 9' on-ground radials and uses an 1:1 choke. Not that I have really bothered analyzing it, but I have no discernable (to me) common mode on the feedline back to the transceiver when transmitting.

End loading with capacity hats is used to lower the "resonant" frequency. If you shorten the primary antenna element(s), you would raise the resonant frequency, thus you could use capacity hats or other typical loading techniques to bring the resulting antenna back to the desired resonant frequency. Thing is antenna loading tends to lower antenna efficiency and narrow the available operating bandwidth from resonance.