Update December 15 2023
So, its been a year now and I'll spare the mystery, the antenna has performed very well. I can say that your not going to break every pile up, but, your odds are improved greatly.
Now a few follow ups. Regarding the failure to repeatedly go back where the copper tapes belong, that's gone. Neither Steppir or I know why. Several theories, was there water inside, I doubt this one, were the copper tapes stiff, Steppir says no, was there foreign matter inside, i.e. that dreaded silicon tape I was inadvertently told to use, that is the most likely. The debris probably migrated beyond the tapes reach. Regardless, the repeatability has improved drastically. I can go months without re calibration. When I need a re calibration, its likely because I changed bands accidently right in the middle of a frequency change already in progress. Even then, its not terribly far off.
Regarding failures, thus far I've had none on the antenna itself and I hope I don't for many many many years. The Optimizer is a different story though. Even though there were engineering changes to make the Optimizer less prone to injury from nearby lightening strikes, my unit has been hit repeatedly. I have the Array solutions arresters on all 24 conductors, but its not enough. You are asking why don't I just unplug the 24 pin connector? Good question, because its VERY VERY DELICATE and you can EASILY induce shorts between the pins inside. So, I do disconnect it when I have lots of time and can be INCREDIBLY careful. I gave up on the Subusb connector, way way to many tiny leads in an even smaller volume. I had several short circuits from it just being moved a tiny bit. I changed over to soldered connections with heat shrink over the pins. Its still delicate but so far I've not had any more shorts. The lightning is a pain, The driver chips get blown. Typically it reads "faulted" and you can pretty well guess what happened. Changing the chips out is a snap, sixty seconds tops. I keep a dozen around here. The Optimizer took one nasty hit and had to go back to Steppir because replacing the chips didn't fix the problem. Disconnecting the cable when your done, why don't I do that? Well because as Steppir will tell you, the motors on the boom are fed low current even when the Optimizer is turned off. Steppir does that so the copper tapes don't migrate out, and thus keep the antenna from losing calibration. Thus its not as obvious as you think to just 'disconnect" the 24 pin connector every time your done operating.
On air performance is really good. On many bands my SWR remains 1 to 1, yep you read it right, even after changing ends of the band. I sold my Flex Radio TGXL, one of the finest antenna tuners I've ever owned, just don't need it with this antenna.
You will notice that you create mini pile ups even though your not DX. I suspect that what happens is, I'm the only signal getting through to various parts of the world and folks jump on me. It can be quite impressive, 10 15 calling for NC. Not exactly rare DX, and my county is hardly rare. Pretty neat really.
Would I buy this antenna again. Given its performance yes. Do I continue to be concerned about failure? Yes I do. Five motors, ten tapes, dozens of wires, relays and on we go. Plenty of stuff that could fail. I hope my concern is misplaced!
Remember, prepare for many hours of assembly and testing....90 for me. Do NOT rush it into service. Steppir now sells it with pre made cable assemblies which will greatly reduce your chance of error and assembly time. Having pre made cables is a SUPER idea. The price of this antenna is well over 10k now so there's that. Tower, Rohn 55g is NEVER going to hold it. I'm not even sure 65g will. Steppir has changed the way they report wind surface and for the positive. READ IT before you buy one. Be sure the tower you plan on using has LOTS of reserve, remember the moment on this antenna is over 7500 ft-lbs of torque WAY beyond most any other antenna. I use a Prosisstel Rotor and its a champ at holding the antenna still even in high wind.
The antenna elements are fiberglass tubes and they bend in the wind so be sure you have those hose clamps good and tight at the boom or your going to have a bad day.
Well I hope that helps I will not update again unless something significant happens. Good luck and enjoy it.
UPDATE March 2 2023
I could edit my post below but I'm leaving it alone in case someone else goes through the journey I have.
So, to update I am satisfied this was a very good investment and here is why I have changed my mind.
Regarding repeatability, I'm going to have to speculate a bit, I suspect one possible explanation for why I had problems that required frequent re calibrations was that a piece of foreign material was in one of those fiber glass tubes. I strongly suspect a piece of silicon tape got loose. There should never have been any of the silicon tape but as noted below, I got the wrong instructions. Now this is rank speculation. I do not know what changed but now for quite some time repeatability has been dead on. The SWR on all bands forward AND in reverse mode has been repeatable and very very low. My worst I think is 1.5 to 1.
Regarding performance, again using the TH11 as the bench mark on tower two, the DB42 is drastically better. Having 3 elements on 30 and 40 meters represents a gigantic advantage. I've broken numerous pile ups comfortably.
Would I buy this again, indeed I would. Now you will see in all of my reviews that I'm not interested in impressing myself with what a great buy I've made. I call em like I see em.
I will continue to update this review over time to document the longevity of this superior performance or if there is any change.
I just want to add that with the DB42, and compared to my TH11DX, I got THREE S units and worked Bouvet. Here is where the electronic reversal REALLY pays off.
The DB42 is difficult to review. The very first thing you need to know before you buy one is, how long does it take to assemble. In my case it took a total of 90 man hours to assemble and thoroughly test on the ground, over three weeks. This is not a complex antenna to assemble, I had two helpers who did most of the work and they weren't even hams.
The manual is a serious problem. I downloaded the latest from the Stepper site and it was wrong. I ended up having to rebuilt significant parts of the antenna. I checked this morning on the Stepper site and the manual is still wrong even though they are well aware of it.
The manual is 99 pages long, I read it cover to cover before I started which helped quite a bit. The parts that were supplied were accurately labeled. You MUST go in order, do not skip ahead.
The boom didn't fit together, we spent 2 hours trouble shooting it, finally gave up as we realized one end of one piece was slightly egg shaped.
You are responsible for cutting those fiberglass tubes to proper length, getting them cut is no small thing. Cutting metal is one thing, fiberglass is quite another. Making the ends precisely square to the tube is not easy. If they aren't then those little sleeves don't cover up any mistakes. Ugh I fear this alone may be a show stopper one day as that copper tape may hook on a tiny gap.
The manual does NOT tell you how long to cut the cables, a gigantic mistake in manual preparation. They, with a bit of a push, at Stepper finally gave me the measurements. They were correct.
The electronics cabinet door wouldn't close because the cables provided are a bit rigid and their bending angle was just a little to long. I worried about closing it with zip ties but that was the only solution. No cable failure has occurred. The cabinet as delivered, had the bracket to boom assembly on backwards.
Communications with Stepper are very very problematic. First they don't even open until 12:30 eastern time, 9:30 PST. They are not available outside of business hours which is almost certainly when most people will be assembling the antenna. So, when you get to a point that you need critical information, you have to wait. The phone is never ever answered. You leave a message and sooner or later someone will call you back. They may or may not be the right person. Communications via email may or may not help either. I found this very troubling.
Even when you think you are done with assembly, the testing process will almost certainly reveal trouble. When doing the wiring, be exceptionally careful or you'll have all sorts of trouble. We were very fortunate. Our wiring was correct immediately. Unfortunately, problems with the mechanics immediately arose. We found that the loops, if not flawlessly assembled, caused the copper tape to jam. Reassembly seemed to have addressed the issue, but we never did figure out what was causing the problem to begin with, very unsettling.
Regarding repeatability, its clear that the gears that feed the copper tape are skipping, just a bit. The result is that tuning 40 meters is something I'm going to have to do on a regular basis. Antenna calibration needs to be done every several days, which is a worrisome sign.
The controller blindly sends out voltage for a predetermined period of time. If the copper tape moves correctly that system works fine. But, if anything goes wrong you either have mistuning or a catastrophic disaster on your hands. If the copper tape were to jam, and other reviews have noted that this happens, the motors are not stopped they just keep pushing out the copper tape until time is up. That their is NO feedback from the antenna to the controller is a huge engineering mistake. Reid switches, something, anything would be better than just sending a command out to move and hoping that everything is OK. This type of open system is the weakest point of the entire antenna.
I was getting "fault needs attention message" but when I went into the menu system, the fault table is empty. I've since learned that when faults happen, they are put in the table but if they go away, they are immediately deleted. Deleting these faults is utterly inexcusable.
This behavior of deleting faults is another example of trouble to come. Ultimately, in my case I have 330 ft of controller cable between the controller and antenna, the voltage drop was part of my problem. I asked about this before I bought the antenna TWICE I was told it won't be a problem. Well it was. I had to spend 70 bucks more to buy the higher voltage supply that Stepper recommended. The antenna should have come with this to begin with. Fortunately this was one of the issues addressed while it was on the ground.
There is a serious Firmware error. Lets say you are on 15 meters and you decide that for SWR reasons you want to recalibrate the antenna. When you hit the calibration button, the display blinks to calibrate, then back to 15 meters in less than a second, then the controller thinks the copper tapes have been drawn back into home base, but they weren't, so the controller attempts to now extend the copper tapes out, even though they are out. There is no emergency cut off option. I have had to pull the power supply out of the back of the controller to stop this behavior To safely calibrate, you must first retract the elements, then do the calibration. During calibration, those motors make some awful sounds. I'm told "don't worry its fine" and "won't hurt anything" but it sounds terrible. I hope they are right about that.
Regarding repeatability, the above says it all.
Durability, I'm suspicious that the need for constant re calibration is telling me something is wrong somewhere.
The antenna was tested on the ground for a week, over 100 cycles looking for repeatability. But, on the ground, the SWR is the only metric available to you and the SWR is so crude its hard to detect with an analyzer tiny issues.
We used a metal detector to determine where the copper tapes were landing when extended on 40 meters. It was a crude measurement because you cannot with precision determine where the tape landed. I mean you can tell pretty closely, but, an inch or two isn't going to be able to be reliably measured.
In the air at 110 feet, its clear on 40 meters that the resonant point moves 20 khz on a regular basis. You have to recalibrate the antenna, which doesn't fix it, then go into the menu system and adjust the element lengths.
Several days later you do it all again.
What about on the air performance. Well, here I would give the antenna 5 stars. When comparing one antenna to another typically these are very subjective calls. In this case its not. I have a TH11 on another tower and can flip back and forth between them. Clearly the DB 42 is a drastic improvement. Two to 3 S units easily. Think of that in DB, its staggering. The ability to flip electronically 180 degrees is incredibly useful. I get through far more easily than I ever had to stations in Asia on a routine basis.
Longevity? I fear for the future, this constant retuning is a major worry. Plus, their are 5 motors, ten copper strips, many relays, probably 500 ft of wire, so taken together longevity is a major concern.
Do I regret my purchase, well partially. The assembly took way to long, the manual being WRONG was beyond annoying, communications being poor is frustrating and worrying about those delicate copper strips up there at 110 feet, maybe hanging up on who knows what, is unsettling to say the least. I mean I can't justify taking it down, I couldn't find anything when it was on the ground.
Conceptually, this antenna is a great idea. But, the implementation isn't quite at perfection. My plan is to use it until something horrific happens and accept that the funds are just gone. I have 16 thousand dollars in it, including getting a crane to put it on the tower so that will be a sad day. Sure its under warrantee, but how useful is that exactly? No one is coming here to fix it, gotta get a crane to take it down, fix it myself, get another crane to put it up. So, as I said when it dies that is the end of that.
You'll have to decide for yourself if the serious performance advantage is worth all the above. The performance is seriously better than anything else. But will it last, will it be repeatable, I think the answer is coming. |
