Tag Archives: K9ZW

Projects at the K9ZW South QTH – New AlfaSpid Rotor

It is maintenance time at my home QTH. Fixing storm damage, wear and tear, doing preventative maintenance and replacing broken things.

I’ve had some serious help from Vern K9EME in the work. Actually too often it must be admitted I was watching as Vern K9EME took care of the work.

A high energy strike nearby (I think it was when a nearby streetlight was “smoked” by lightning) had finished off an increasingly unreliable rotor, taken out the half-sloper, and I had some damage occur at the same time to the larger Log Periodic antenna, with one element suddenly impossibly drooping.

Fixing the half-sloper was easy. The solder from the main wire to the connector was gone – simply burnt away, and soldering things back together and inspecting took care of that problem.

Swapping out the rotor, an old Ham-IV for a new AlfaSpid RAK was a real challenge.

This tower is a Tri-Ex LM354 and is a motorized crank-down with manual tip-over.

Here is the new rotor going into place:

AlfaSpid RAK replaces Ham-IV

AlfaSpid RAK replaces Ham-IV

 

The AlfaSpid RAK rotors I have all came from Alfaradio.ca in Edmonton Canada. The units are built in Poland, are a very different design than the typical small ham radio rotors, are unfortunately a bit pricey but offer great precision, high reliability, better capabilities and more precision.

Here is a bit closer what it looks like:

 

The AlfaSpid RAK up close

The AlfaSpid RAK up close

 

It was challenging work to get everything sorted and K9EME’s experience made all the difference.

As there was very heavy duty eight-wire rotor cable in place, we wired the four-wire AlfaSpid with double wires on the sensor connections.

After verifying everything with a multi-meter we photo-documented how we wired it:

Photo-Documentation is a Good Thing!  RAK wiring up close

Photo-Documentation is a Good Thing! RAK wiring up close

Cannot tell you how useful pictures are when years later something needs fixing or replacement.

Getting the Greenheron controller operating with the AlfaSpid didn’t go well, and I called Jeff at Greenheron who quickly help me figure out the protective TranZorb diodes had been fused along the way. A quick temporary fix and all was well and replacement diodes were ordered online.

The Tennadyne T-8 is actually missing a bit of the square boom at the lower longest element. I have a call into Tennadyne for the spares, but it is hunting season in Michigan and Wisconsin, and I got the answering machine,

I have a concept for a repair that should stand up for now. More in another post.

I’ll spare sharing the inspection and PM, but when you have a tower down and over it is a good time to do a full service.

73

Steve
K9ZW

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When North is not North – Deferred Maintenance has a Price

Spring at my home QTH brought some real weather extremes, including a few very high wind events.  If I know about forecasts for mega-winds in advance I will retract my tower and point the pair of Log Periodic (LPDA) Antennas into the expected direction the wind is forecast to arrive from.

But a couple times I wasn’t around or arrival of major winds wasn’t forecast, and things had to take the brunt as they are.

LPDA antennas typically have two square booms spaced apart electrically, each with half of the elements on them.  This is a fair bit of a wind-catcher compared to a typical beam where one round boom does duty.

On my heady-duty version of the Tri-Ex LM-354 tower are a Tennadyne T-8 10-20m LPDA and a T-28 6m-1.3gHz LPDA.  Book Wind Areas are 8 sqft and 3sqft, for a total if some off-center allowance is given for the chokes of approximately 12 square foot of Wind Area.   The tower in standard form is rated for 26 square feet of Wind Area using the standard design and the current heavy-duty is rated for 52 sqft, so nothing about the antenna loadings themselves being pushed hard there.

Tri-Ex/Tashjian: http://www.tashtowers.com/crank-up-towers.php

Tennadyne:  http://www.tennadyne.com/specs&prices.htm

I’d retrofitted the T-8 with SlippNott high strength attachments back in 2013 – https://k9zw.wordpress.com/2013/06/09/installing-slippnott-upgrades-at-k9zw/  which included an added fitment at the rotor to secure the mast.

The winds had slightly pushed the T-28 from its alignment with the T-8 and rotation is now indicating about 95 degrees further clockwise than actual.

There is a chance something electrical is messed up, as the same high winds did pull all feed lines and rotor cable from the standoffs.  Apparently the breakable restraints either died with UV, Cold and Age, or the winds were strong enough to peel the lines free.

Otherwise either the rotor has broken free or something has slipped.

Of course it is raining, the ground soggy, cold and the scaffold I usually use for service one the tower is down and tipped over just happens to be 130 miles (including six important water miles) away ay the Island QTH.

I have a freshly rebuilt Ham-IV rotor which would be an easy swap if it is a rotor issue, or this might be the time to put in the AlfaSpid RAK Rotor I’d bought at Dayton-2014 but hadn’t yet installed.  Being a bit lazy about replacing things that are working okay, I’d changed my mind and I’d intended the AlfaSpid to go to the Island QTH.  So if I use it I will need to buy another.

Usually every Autumn the Tower gets lowered and tipped over, and a full PM (Preventive Maintenance) completed.  Because of the acquisition of the Island QTH and a heavy work load this PM got skipped in 2014 and 2015.  My bad, to say the least.

So now I get to pull the PM with an extra Troubleshooting Task.  Want to bet I made something worse by skipping the PM?

73

Steve
K9ZW

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K9ZW Northern Island QTH .. General Layout

It is obvious the new Washington Island QTH is a FlexRadio System Station first and a Vintage Collins Station second.

I’ve done a quick sketches how the layout will work.

K9ZW North QTH General Layout – outside

and

K9ZW North QTH General Layout – inside

The Antennas are:

  • HF Multi-Band Receive only – KD9SV RBOG (Reversible Beverage On Ground) units, aimed NW, SW, NE, and SE, using a convient existing buried pair of high grade 72 ohm cable to feed.
  • HF 80-10m Vertical – Zero-Five Flagpole with 30 radials
  • HF 160-20m – W9INN Half-Sloper
  • HF 40-6m – SP7IDX Hexbeam

Feedline will be Andrews Heliax I now have on hand.

73

Steve
K9ZW

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K9ZW Northern Island QTH .. First Steps

Have a lot going on putting the new Washington Island QTH together, with a TriEX Skyneedle waiting for a new base from Tasjian and other pieces starting to show up.

With the tower base I’d also ordered a work platform which will let me do most antenna work without a lift, and new coax standoff arms.

From the radio room to the tower base I have sourced enough Andrews 1/2″ Superflex HELIAX FSJ4-50B to ru two feeds and a separate feed to a vertical antenna.  This cable is very low loss, with amazing numbers like under 1 dB total attenuation per 150 ft feed line with working capacity in the 7 kW range!  Velocity factor is 81% for a fairly standard set of characteristics for calculating correct lengths to reduce unwanted electrical and RF characteristics.

The SP7IDX multiband Hexbeam is due in country in a few weeks, right on time.  The W9INN half-sloper is on hand and ready.

Intending to install a Zero-Five commercial grade flagpole multiband vertical antenna, which is especially cool as I really am keen to have a flagpole as well!! I’m going to start with 48 radials cut in sets of six per band.

Planning two KD9SV RBOG reversible on the ground beverage antennas. The pair of 180 foot long RBOG antennas installed in two directions will cover the four “Prime” directions (one NE/SW and the other NW/SE.). Gary KD9SV sells through DX Engineering and I think I have sourced a large roll of military surplus cable that should be a good match for the RBOG antennas. I hope to actually bury these receive antennas to keep them out of harm’s way. If the ends can come together, I already have buried feed lines from an old satellite internet installation.

I’ve bought a 25kW Lp-gas Kohler generator with automatic switchgear for a full site backup. With the power regularly interrupted or running off voltage on the island the plan will be to run all radio gear possible to run off DC from a battery farm and use the generator or mains power to recharge the batteries.

In the morning a local builder is visiting to review the plans for a garage, but I have changed my ideas to keep the operating station in the main house for the foreseeable future.

Another contractor is stopping by to look at road improvements and preparation for pouring various slabs.

Back to the tower the Heliax will terminate at a base of tower cabinet which is where antenna switches and lightening protection gear will also go. From the tower base box up to the antennas will go Davis RF’s BuryFlex cable, which is one I have had very good luck. A nominal 80ft of that coax plays the BuryFlex jumpers to get to the radios from the shack end Heliax termination will add up to on paper under 3 dB total losses.

Back at home the Alfa-SPID rotor should get mounted this week, and all touch up as well as a new Sheetmetal rotor cage cover will be ready before transport to the island.

A PC-on-a-USB-stick now has a nice 28 inch LED monitor, the combination which will initially drive the Flex-6300 Tranceiver.

Given my limited time on the Island and the late start I had, reality is I will be happy to have the tower and main antennas up before winter.

73

Steve
K9ZW

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Start of limited Island Operations

In the last few trips to Washington Island I’ve had the chance to starting making QSOs from the new QTH on a limited basis.

I’ve also operated a bit from George W9EVT’s shack, with both my gear and his.

Put the trustworthy SteppIR CrankIR into the antenna slot while a new base for my tower is fabricated.  Running from Indian Point has been a Swan 350 and now my Flex-6300.  From Greegate Farm, Goerge W9EVT’s QTH I’ve used my Collins KWM-2A and George’s Icom IC-7800.

Contacts have been SSB and PSK

The strong winds had the CrankIR tipped over twice, and I caught a third push over, so something has to be sorted out there.  I’d used the speaker stand base, and need to sort out a better situation.  At Indian Point there is an old dish from satellite internet (these folk wanted $100/month to do basically dialup with buffer burst!) which has a suitable pole concreted in.  Next visit I will clear the old dish and set the CrankIR on the bare pole.  Unfortunately the buried coax is actually Twinax 72 Ohm stuff, and while the install was first rate and attractive, a protective sleeve was used rather than a conduit, so no pulling new in the same sleeve.

i will  bring up the TDR and Megaohmer to see if perhaps I can still use the cables, though I doubt they are QRO rated.  Even if they can be used for control wiring that is better than throwing them away.

Doing a lot of thinking about how I want to set up this QTH.  Should the operating station be in the main house or a separate workshop?  What does the LAN Remote of Maestro mean to the design for those operations?  Am I better to put the station gear in the house now, rather than wait for an unbuilt workshop?  Or should I buy a trailer to use as the workshop until it is built?

I am leaning towards putting whole station in the house, and consider the eventual outside workshop a more rough and ready workshop rather than a ham shack sort of place.  The cost savings of keeping everything in the house are significant, that is if I want water and heat, not to mention a toilet near the work station, as these services would need to be brought to a new workshop.  That is a lot of rock to hammer out to put in services Is I go the second building with heat and plumbing route.

Rather I am thinking to keep the house shack area and the former woodworking workshop clean enough to do electronics, the ham shack and some musical instrument repair, relegating the heavy/dirty workshop tasks to the outside building.

Lots to think about!

73

Steve K9ZW

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K9ZW Northern Station – The Tower and the Antennas

K9ZW Northern Station – The Tower and the Antennas

The Tri-EX/Tashjian TM-370HD Skyneedle is here at a friend’s trailer yard, where we will do some light refurbishment (scrape and paint some light tin parts that are showing surface rust) and fit the Alfa-SPID RAK Rotor, while we wait for the new base and a few added accessories to arrive.

Here are a few pictures of the tower being removed from storage and transported to my friend’s trucking yard:

Crane lift of the TM-370HD

Crane lift of the TM-370HD

TM370HD_Out_of_Storage_02

TM370HD_Out_of_Storage_03

A bit about the TM-370HD – this is a motorized 70 foot tubular tower that has some pretty impressive numbers.

I have a full set of engineering calculations and the wind loading they cite is roughly five times what my array will be, and perhaps 35 times the weight load is available.

Not certain if the numbers they provided are after application of the designer’s safety factor (would presume so, as they were done for code compliance rather than product engineering) so the ultimate wind loading and weight bearing is truly impressive.

Initially going up is a SP7IDX Hexbeam HD Mark II antenna currently in production, and a W9INN Half-Sloper which I had on the ready.

The Hexbeam will cover 6m to 20m and the Half-Sloper will carry onwards 20m to 160m.

I thought I had another Tennadyne T-8 antenna locally sourced, but the present owner decided he didn’t want to sell it even though he’d just advertised it. I’d been interested in having both the LPDA and Hexbeam up to do some A/B comparisons.

Karl and Norman at Tashjian Towers Corporation have been super as usual.

They have in production a new base for me, and I am adding the work platform (tower already has the ladder) which will allow me to do 98% of service work without a lift.

That the work platform will make an awesome birdwatching and other outdoor pursuit platform hasn’t escaped me either! It is quite likely that it will also open up a way for my getting very high speed internet to this QTH, as aDSL isn’t going to quite cut it for remoting a full Flex-6000 based station.

There are a lot of logistics to go – I have verbals from the professional help to get the base in and the tower up, and I have access to a DitchWitch to bury the conduits needed. ( want to run the power separately from the coax feeds and other control wiring.)

I even have some nice touches to add features, like a set of industrial/maritime intercom units so one will be at the tower and the other in the shack.

73

Steve
K9ZW

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