While there are still a few more improvements to make to the overall system (lowband antennas, more grounding, etc.), I’m generally back on the air. First QSO was with BT1OY (Olympic special event station in Beijing) on 20 meters SSB.

Repair costs were roughly $1170 for the SteppIR control box (replaced), Prosistel control box (repaired), Icom IC746 (repaired), and DC power supply (replaced).  That does not include Dave’s time on the tower.  Still waiting to hear from our insurance guy on what would be covered. Thankfully, no damage to anything in the house other than ham gear. I suppose that it could have been much worse.

This whole process highlighted for me the things I like least about the Prosistel Rotator (an otherwise very good piece of amateur radio equipment).

1. The software provided by ProSisTel to test/calibrate/adjust the rotator is awful. It might be fine for a hardware developer, production guy or repair tech – but to provide software like this to end users is not good. My beefs with the Prosistel rotator software are:
   • The user interface is bad. Really bad.  Data field range checking issues, terrible color scheme, buttons with labels like
     “cmd L” (below) – this program needs help.
     
   • Error messages are confusing, along the lines of “Communications timeout on <header>”. 
   • It only provides access to 4 com ports.  Getting the Prosistel rotator controller to communicate with my PC is  a chore. 
   • The latest version I could find on-line is over 3 years old – which would be acceptable if it lived up to expectations.
2. The documentation has a lot of room for improvement.  It was revised to include an error that I complained about (pot resistance values were incorrect leading me to some extra headaches when I first installed my PST61D).
   
   
3. We had to remove the rotor from the tower and pull the bottom cover off to get to the MOVs – which had to be removed. You could argue that the MOVs saved the pot – but I already had a ICE rotator line surge suppressor in place which might have taken the blow instead.  Anyway, when the MOVs blow, it would be nice to remove them without taking the rotator off of the tower.
   
4. Slippage on the mast-rotator coupling.  We did not “pin” the mast to the rotator, but we may have to change that.  I did notice a fair amount of slippage due to strong winds. Apparently, I’m not the only one who has seen some mast slippage in a Prosistel rotator.

Now, that said, this still seems to be a very good rotator that has stood up to the challenge. I just need to refine the installation. I can live with the sloppy config software and documentation (two things that I should rarely need to use).  I was eventually able to sort out my serial/coms issues and get the rotator back on track (with the help of my Black Box DB9 Pocket Tester).

Now, with all of that said, would I buy another Prosistel PST61D? 

At this point, I still think that it is the best choice for my application. I want something strong up there – and this rotator has the best specs on the market in its price range…

In my mind, the Prosistel PST61D still compares favorably to other rotators (HyGain, M2, AlfaSpid, Yaesu) in this class.

Weather was nearly perfect (no wind, ~82 degrees) and we were able to get everything safely on the ground without a major incident.

What we learned…

• Prosistel PST-61D rotator motor works (12Vdc will turn the motor) but the heading indicator (pot) was giving bad readings (~91 ohms). I was able to open the bottom rotator cover and found 4 fried MOVs (see pic).  Per instructions from Jay @ ArraySolutions, I have cut these off of the potentiometer and the readings are now normal. Lightning protection for the rotator will continue to be the ICE rotator line transient suppressor mounted at the tower base.
• The 4 element SteppIR could not be tested as the replacement control box has not yet arrived from the factory. However, we did notice deterioration of the rubber coupling “boots”.  Apparently, SteppIR had a supplier issue with these that has now been resolved. For some period, there were antennas shipped with these rubber (plumbing) couplers that were prone to UV damage.  I need to replace these – and I need to test the antenna itself.
• The AlphaDelta DX-B 1/4 wave sloper was removed.  Again, I had low expectations for this antenna and was never really happy with it (even though it only cost me $15).  I now have the parts for my 80 meter and 160 meter inverted Ls.
• The Cushcraft XM-240 two element 40 meter yagi  still needs to be thoroughly inspected and tested. It’s now sitting on two sawhorses over the SteppIR. SWR does not look good – but there could be many reasons for that, including the MJF 259 antenna analyzer issues from nearby broadcast antennas that I saw last fall and proximity to ground.

There is certainly a lot of work ahead, but thanks to some great help from some local hams, I now have a better idea of what needs to be done.

One hot & muggy summer afternoon, I was driving home when a major storm hit central Iowa.  My daughter’s school, a mere mile away from my house, recorded 80+ MPH winds before the weather station was blown off of the roof!

The good news is that my tower and antennas did not take any damage as a result of these strong winds.  Straight line winds blew cars off of Interstate 35 and snapped massive trees like twigs.

Lightning strikes twice

The bad news was the lightning. My next door neighbor said that my tower was struck twice during the storm.  It’s hard to know if these were both direct hits. The first strike was apparently a massive hit that shook the walls/floors of nearby homes.  He said that two houses on our street lost their wireless Internet transceivers. One neighbor reported that his battery operated Christmas ornaments started playing music in the attic.

Assessing lightning damage

I am still assessing the damage due to these hits.  My HF transceiver (Icom IC-746) was thankfully not plugged into the coax runs from the tower.  However, I did have an outlet strip that was plugged into the wall in the shack (ouch) – it was feeding my:

• Prosistel PST61D rotator controller
• SteppIR 4 Element yagi controller
• Samlex 1223 power supply (connected to the Icom)

All three of these were toast, as was the IC-746 and an old TV on the same circuit.  Arraysolutions‘ rotator repair guy was quick to review the controller… the main circuit board needed to be completely replaced. SteppIR was also very quick to assess the damage to the controller…. a total loss. The IC-746 was shipped to Willco Electronics. No word yet on the damage there.

I have not yet assessed damage on the tower. Equipment prone to lightning damage would be the Cushcraft XM-240 (balun?), SteppIR 4 element motors (doubtful), rotor internals (MOVs?) and the protection gear itself installed at the base of the tower.

I did find a PL-259 coax connector (for the XM-240) that had black char marks on the shield and the center pin.  My theory is that the lightning struck either the ANWireless tower itself or the XM-240 40 meter yagi and induced a surge onto an AC line that runs to the tower in the coax trench.

Reviewing and Improving the Lightning Protection System

Along with the still unknown amount of repairs, replacements and insurance headaches, I’ll be spending time trying to make the system a bit more bullet-proof. Immediate changes include:

• AC surge protection in the shack (already ordered through Amazon)
• Additional ground rods (currently have 5, 8 ft ground rods – will probably add another 5)
• Better grounding and a new layout of the surge suppression gear enclosure at the tower base. I wonder if the tight enclosure could have been an issue (arc?)
• Review what happened in the I.C.E. lightning suppression boxes (components blown?, bypassed?, ???)
• Consider a SPG panel at the house – entry point.
• Always disconnect everything when not in use. Period.

In trying to decide which approach to take, I’ve done some lowband antenna modeling of inverted Ls and shunt fed towers. I have also asked for advice on the best 160m/80m antenna approach on the towertalk/topband forums. 

My plea for help on the towertalk and topband forums was met with with many great responses. Some guys went to great lengths to review the situation and provide input.

Quite a number of hams suggested that I shunt feed the tower. While that does seem to be an attractive approach for a number of reasons, there are some drawbacks in my scenario:

• The Cushcraft XM-240 40 meter yagi at the top of my stack is susceptible to overheating when the tower is shunt fed. 
• Exposing the SteppIR 4 element controller to voltages when the tower is shunt fed is also a concern. However, many have reported that there could be an advantage to using a SteppIR on a shunt fed tower in that some tuning may be accomplished with this approach.

At the moment, I think the approach I’ll take is two inverted Ls: one for 160m and one for 80m. This pair of inverted Ls will be driven with a variable capacitor of some sort.  There are downsides to this approach… extra wires in the yard, probably will be tricky to tune, and some interaction causing a distorted pattern on 80m.

Still many things to be worked out on this… housing and control of the capacitor, band switching, installation of standoff arms, etc.  I’ll post more as this develops- but feel free to comment if you have ideas on lowband antennas with a self supporting tower.

Today, Brandon sent me a picture of the completed cake – featuring a mega-calorie version of my ANwireless HD-70, SteppIR 4 ele and Cushcraft XM-240. 

The concept of a "groom’s cake" is relatively foreign for us in the Upper Midwest.  My wife’s first reaction was to laugh… then I explained that this cake was not "the" wedding cake and she seemed to be ok with the idea. 

In fact, Lynne has been kicking herself for not thinking of incorporating my tower on my birthday cake last fall. She has ordered those picture cakes in the past… but she didn’t think of it when I turned 40 last year shortly after installing my first tower. Brandon’s cake would have been perfect.  Oh well… maybe next time.

However, you might be able to learn from my mistakes by reading this blog and the ham radio tower project pages.  My wife also mentioned the project in our annual Christmas letter – so relatives who are curious can see what I’ve done to destroy our backyard and skyline. 

The problem

Just to recap what I was seeing… I had the rotor installed and antennas pointed to 000 (North). After some work (another trip for poor Dave up the tower to reset the stack) everything lined up.

However, if I tried a turn from 000 (N) to 90 degrees (E), the antennas would turn ~170 degrees.

I was certain that I had wired everything properly – so I began to suspect that the rotor itself was not wired properly at the factory. I had found a email thread on the internet from another ham who had a similar problem and traced it to an internal wiring issue.  So, I followed the documentation’s troubleshooting section which described expected resistance values for various combinations of lines (pins). Here is what I saw vs expected:

Pins 1 & 2: 6 ohms (as expected)
Pin 1 and ground: Open (as expected)
Pin 2 and ground: Open (as expected)
Pins 2 & 3: open (expect ~2k)
Pins 3 & 4: 2k (expect ~8k)
Pins 4 & 5: 9.8k (expect 10k)

Ah hah! (I thought).. looked as if some lines are switched somewhere. Before I began switching wires around though, I thought I’d send an email to Prosistel & ArraySolutions to ask what they’d thought.  I was surprised when Gianni (I7PHH), tech guru at Prosistel, wrote to say that those values were all ok.

The Solution – reset the cal factor

Gianni suggested that I recalibrate the control box back to the factory set values – including the “Calibration Factor” which should be printed on the back of my control box. As my box didn’t have that printed on the back, I thought I was doomed to a lengthy calibration procedure. However, he replied:

You don’t need to do the whole recalibrate procedure, just input one of the following numbers and check which one give you the right antenna position.

13914
13981
14049
14118
14187

My Cal Factor was set to a software default value of 8000. Bingo! Entering one of those magic numbers solved the issue – aside from being 180 degrees out of whack. (Which I corrected by switching to North Stop).  I imagine that this value translates to some internal scaling of an A to D counter used to measure the position (looking at the 0 to 5 VDC values across the pot swiper). Anyway, that worked and I’m happy.

Prosistel Alignment – Lessons Learned

Here are my lessons learned from installing and aligning my Prosistel PST-61D (Bigboy):

• The documentation is far from perfect. If in doubt, call or email for support.
• When you get the unit, write down the magic value (Cal Factor) associated with your rotor. If your unit is old enough, this is critical. It should be hand written on the back of the control box.
• Test, test and retest the rotor and control box (Prosistel or any brand) on the ground prior to installation. I tested to make sure it could go CW and CCW and figured it worked ok. Also test to make sure it’s going the right amount (a 90 degree turn on the control box translates to 90 degrees at the rotor).
• Things will go wrong. When they do, it’s good to buy a product from folks who know what they’re talking about and are willing to support it. Although the documentation and support software could be improved, the email/phone support for the Prosistel was very good.

When Dave setup the antennas – he pointed them due north (000 degrees).  Unfortunately, I had left the control box at about 110 degrees.  I had figured that this controller was fully adjustable and if my settings were off I could recalibrate the heading on the control box. This is true to a certain extent.

The Prosistel rotor controller only can compensate for a heading (offset) of + or – 70 degrees. So, there was really no way to working around this other than another trip up the tower for poor Dave.  Actually, I’m writing this from the Denver airport – while Dave is at my house on the tower doing this! (Dave’s a great guy)

Anyway, lesson learned.

On a positive note though, the support from ArraySolutions was great. I managed to somehow corrupt my installation of the Prosistel (RS232) controller software. Jay spent some time helping me through it and that was appreciated.

On Saturday, Duane and I continued to work on cabling and grounding. I pounded 3 ground rods using a borrowed ground rod driver. Eventually, there will probably be 10 ground rods in the network connected by solid copper wire and bonded to the tower and house ground.

Dave (KIØQ) came over in the afternoon and finished securing the coax to the tower. He also installed the AlphaDelta DX-B Sloper (for 160m, 80m, 40m and 30m) on the tower at about the 50 ft level. If you click to enlarge the tower picture, you can just barely see the lowband sloper.

I finished building the enclosure for the base of the tower to hold the ICE lightning protection equipment. This box is weatherproof, has built-in cable ports, and a nice door (with a window!). Best of all, it was free. I mounted a sheet of thick aluminum in the enclosure to fasten the surge suppression gear for the coax & rotor cables.

Throughout the weekend I was able to catch a few hours (<4) of the CQWW SSB contest (that’s the CQ magazine World Wide Single-Side Band (or voice) competition). The goal of the CQWW ham radio contest is to work as many ham radio operators as possible within a 48 hour period concentrating on those outside of your geographical zone and country. My personal goal was simply to test drive the new antennas a bit.

I was able to work at least a few stations on each of the major ham radio bands available in the contest.

Certainly, not a world record – but I was able to meet my goals…

• a few contacts on each band,
• several DX contacts (South Africa, Galapagos Islands, Caribbean, Europe, Gambia, …),
• find out what my antennas would do
• have some fun along the way.