On July 29th from 4-6pm, Matt Strelow, KC1XX has kindly offered to provide a 2-hour tour of the KC1XX superstation to members of the Nashua Area Radio Club. Matt hosts a multi-op/multi-transmitter station with as many towers (to cover all the amateur bands), as there are colors in the rainbow. As you can see from the pics below, we are in for quite a treat.
Currently, the people I have registered to attend are:
If I missed anyone, please send me an email at [email protected] and let me know. Apologies if I did.
The meeting place will be:
814 Hurricane Hill Rd. Mason, NH 03048
Fred AB1OC, who has been there before, has mentioned that parking may be limited at Matt’s. As a result, I have heard non-nefarious machinations that people will be carpooling from HollisBrookline High School (where Field Day was hosted). If you are interested in pursuing that route, then please email me at [email protected]so that I can put everyone on the same email to coordinate. Presumably, the carpool(s) will want to leave by about 330pm or so.
Matt hosts a serious HF world-contesting station — he is easily among one of the top stations in the world. You can also visit his website to learn a bit more. If you are interested in seeing marvels in engineering and contesting, then consider signing up for the tour by emailing Brian AB1ZO at [email protected]. There is still time! But please do it soon. I’d like to get back to Matt with a final count by Wednesday/Thursday.
We’ve been thinking about building a portable Go Kit for VHF/UHF Emergency Communications (EMCOM) and Field Day Applications for a while now. The following is a list of our requirements for a Go Kit –
2m and 70cm operation with FM simplex and repeaters
APRS capability and tactical display for portable coordination
The heart of any Go Kit is the Transceiver. We’ve been using Kenwood equipment for our APRS iGate for some time now and we have had good results with it. Kenwood’s latest 50W transceiver with APRS is the TM-D710GA. This unit provides full support for APRS tactical applications and now includes a built-in GPS receiver making it ideal for our Go Kit application.
AvMap GeoSat 6 APRS Tactical Display
We have been using the Kenwood TM-D710 along with an AvMap GeoSat APRS display in our APRS iGate setup and the combination works very well. The AvMap display lets one see the location of portable and mobile APRS stations on a map display. This arrangement is perfect for coordinating activities in an EMCOM situation. The AvMap GeoSat 6 APRS display is no longer in production but I was able to locate a nearly new unit on eBay.
EMCOM Go Kit Packaging
iPortable Enclosure
We had a chance to look at the iPortable enclosure at Dayton and decided that their Pro 2 4U deep unit would be a good choice for our Go Kit application. The iPortable enclosures are based on a portable rack mount case and include a DC power system, speaker and headphone hookups, a light, and provisions for a cooling fan.
EMCOM Go Kit Construction
Radio Shelf
With all the components in hand, we began the construction of our Go Kit. Reliability is important in any portable system like this so we put some time into securely mounting all of the equipment and neatly arranging the cabling. First came the shelf which holds the Kenwood transceiver and a SignaLink USB sound card. A combination of drilling the shelf to secure gear with large cable ties and #8 stainless hardware was used here.
Coax Connector Cables
Our iPortable case was equipped with both SO-239 and N-connectors on the front panel to allow for antennas and feed lines equipped for either connector type. To make the change over between the connector types easy, we installed separate PL-259 jumper cables for each connector. One simply connects the appropriate jumper to the radio.
Display and Power Shelf
The power and AvMap display shelf were next. The AvMap display mount was dissembled and modified to accept a custom mounting bracket.
PWRgate Battery Interface and Charger
The iPortable enclosure was drilled to mount a West Mountain Radio PWRgate to handle backup battery charging and management. The PWRgate supports instantaneous switching between an AC power supply and a backup battery and can accommodate a wide range of battery types and sizes.
Backup Battery
The PWRgate was configured to properly charge our 18AH AGM backup battery. Note the use of a fuse in series with the battery for safety reasons. We used a Powerwerx SPS-30DM adjustable power supply set to 14.5Vdc to operate our Go Kit and to provide the proper charging voltage for our AGM battery.
EMCOM Go Kit Operation
Diamond X-30 Antenna and Mast
The last piece of the setup was the antenna. We wanted something that was portable, easy to set up and would provide good performance. We choose a Diamond X-30A 2m/70cm ground plane antenna and mounted it on a 12′ fiberglass push up mast. The feed line is made from 25′ of LMR-400UF coax. Several bungee cords are used to attach the mast to a fence post or other vertical structure.
Finished Go Kit In Use
The picture above shows the completed Go Kit in operation. We typically set one side of the Kenwood TM-D710GA to operate as an APRS transceiver and Digipeater and the other side to operate on a local repeater or simplex FM. The SignaLink sound card is used with a laptop computer running Fldigi and NBEMS for messaging applications. The iPortable case has a 13.8V lighter socket which connects to a power brick to power our laptop PC.
Go Kit Packaged for Transport
The Go Kit is quite portable when closed. All of the equipment and cable connections are enclosed and protected by the case’s removable end caps. We’ve tested our Go Kit during our club’s weekly repeater net and it worked great. The first real use of our new Go Kit will be at Field Day this year. It will be located in our public information tent and will be used as a “talk-in” system.
We decided to put up a third tower as part of our 2017 Field Day operation. The new tower will support a tri-band yagi and wire antenna for use by our Digital and GOTA stations this year. Our Field Day plans call for this tower to be located on the middle-level soccer field at the Hollis-Brookline High School. To overcome terrain limitations, we decided that our new tower should be a 60 ft setup.
The project began with some mechanical design and planning for a new, heavy-duty Falling Derrick System. Mike K1WVO, Dave N1RF and I secured the necessary materials and hardware to make the new Falling Derrick System.
Equipment And Tools On Site
The team in the two pictures above met at our QTH this past weekend to transport all of the equipment for the new tower to the high school for a test setup.
Setting Up The Tilt Base
The first step in the test was to locate the tower base in the center of our test area and ensure that it was level. Steel stakes were driven and retainers added to secure the base to the ground.
Building The Derrick
Next, we assembled the falling derrick and the first section of the tower to the base.
Assembling The Tower
With the Derrick in place, we assembled the remaining sections of our 60 ft tower on the ground.
Driving Guy Anchors
WIth the tower, Derrick and base together; we carefully located and drove the steel stakes for guying the tower, the derrick and for anchoring the pulleys associated with the falling derrick system. With this done, we made up and attached two levels of guys between the tower and the anchor stakes.
Completed Heavy Duty Derrick System Ready To Lift
The tower is lifted by two wire cables which run between the derrick and the tower. We made these cables up to length during our test session. Multiple cables are used to ensure that the tower is fully supported during the lift.
Completed Derrick System – A View of the Tower
Here’s another view of the tower and Derrick prior to the lift. We supported the tower on a ladder to make the initial lifting easier. The ladder will also be needed on Field Day to allow our tri-band yagi to be installed on the tower prior to standing it up.
Capstan Winch Used To Lift Tower
There is a considerable amount of rope that needs to be pulled through several pulleys to lift the Tower/Derrick system. The pulleys provide mechanical advantage and slow the lift rate to a safe level. We used a heavy-duty gasoline powered capstan winch to pull the considerable length of rope required to lift our tower into the full upright position
Lifting The Tower
With our crew fully briefed on the process and safety procedures, it was time to lift our tower. The picture above shows the lift in progress. Our setup ensures that no one needs to be in the tower’s fall zone during the lift.
The Tower Is Up!
Here’s a picture of the tower after it was up and fully guyed. Our new heavy-duty Derrick system worked very well and lifting the tower was completed smoothly and safely with very modest effort.
The Nashua Area Radio Club Tower Test Team
After a few pictures, we took the tower down and disassembled it. We had quite a few members turn out to help us with our new tower test. Thank you to everyone who pitched in to make our third tower project a success! We are looking forward to using it during Field Day 2017!
Notice: falling derrick tower systems can be dangerous if they are not engineered, built and used properly by a well-trained team. The tower system described here is unique and is not a standard falling derrick system. Significant steps and material choices were taken to ensure the safe use of the system described here to put up our tower Time was spent to train the team who used the Derrick system to use it correctly and safely. We do not recommend the system here to others as the engineering, materials, and training required for its safe construction and use may not be readily available.
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