VHF Tower Electric Winch
Updated
29-Oct-2011
00:00
[back to W1TR Antennas and QTH]
I would like to thank W4ABC for posting this idea on his web. I had been looking at this hoist and others like it but was unsure whether to proceed or not until I saw that he had it working already and there was little risk to trying it.
Manual Winch on the Tristao HG52SS Tower
This is the original manual winch that comes with the Tristao HG52SS crank-up tower. I decided that I was too lazy to manually crank up / down this tower very often having been spoiled by the larger LM-470D tower which comes with a motor as its standard configuration. During bad weather, I often park my towers at half height to reduce the risk of damage. Antennas are easily replaced but not towers! Often I have avoided raising the tower all the way up for the Monday night VHF and UHF nets because of this inconvenience, and have even operated a VHF contest or two with it at half mast. This hoist is indeed the solution to this laziness!
Electric Winch Installed 28-Oct-2011
This looks like a mailbox, but under the hood is a hoist to replace the manual winch that originally came with the tower. The plastic mailbox (available for $10 at Home Depot) is used as a weather shield since the hoist is not intended for outdoor use and must be protected.
Hoist on Mounts Without Weather Shield
With the mailbox / weather shield removed, it looks more like a winch. It is in fact a Harbor Freight 650 pound hoist mounted upside down. A hoist should be used for this application instead of a winch because of the difference in meaning of the ratings. A winch is rated to pull a certain amount of weight horizontally, like pulling a boat out of water or a car out of the ditch. A hoist is rated to lift, lower, and statically hold a heavy object such as an engine from a car, etc. The entire HG52SS tower weighs 550 pounds, and if it is assumed that the mast and antennas weigh 100 pounds, the entire weight of the tower and antenna system can be lifted by this hoist. However, only the top 2/3 of the tower will be lifted giving about a 150 pound safety margin on top of that already built into the hoist ratings.
Another View From Below
The two mounting brackets are constructed from square and L-shaped steel stock with holes on 1 inch centers (available at Home Depot). Stainless Steel bolts fasten the parts together, and 2 inch centered U-Bolts fasten the vertical members of the bracket to the tower horizontal cross members. The original bolts in the bottom (I mean top since it is upside down) of the hoist frame had to be replaced so they would be long enough to also go through the 1 ˝ inch square steel stock. A notch in the L-Shaped stock had to be cut to make sufficient clearance for bolting the diagonal member to the horizontal member. Note the two drilled and tapped holes in the side of the hoist frame used to bolt the weather shield onto this frame. There are two more hidden on the back side. The four-in-a-line recessed hex head nuts in the bottom of the hoist frame are used to fasten the hoist to the frame.
To attach the tower pull-up steel cable to this hoist, the existing cable must first be removed. This is done by first unwinding the existing cable and then detaching the hoist mechanism from the frame by removing the four recessed hex head bolts in the bottom of the frame. There is a bearing to the right of the frame that more evenly distributes the force from the weight of the load. The hoist mechanism must be moved to the left once the recessed hex head bolts are removed and it will come out of the frame. There is a plastic retainer or nut that may come loose from the right end of the hoist spindle, be careful not to lose this, and be sure to replace it when reattaching the hoist mechanism to the frame. The steel cable is attached to the spindle by a small wedge that is inserted in a steel cable loop (it will be obvious when you see it).
Weather Shield Made From Plastic Mailbox
Note the horizontal slot cut in the top of the mailbox weather shield so that the steel cable can play freely with it attached to the hoist frame. To facilitate removal / replacement of the weather shield, the back side of it is cut (see the black electrical tape covering this cut just to the left of the steel cable) so that it can be fit onto the hoist with the cable installed. Note also that the bottom of the mailbox also must be cut out so that it can be mounted on the hoist frame.
Secondary Weather Shield Made From Mailbox Bottom
The bottom cutout piece of the mailbox is used as a secondary weather shield when the hoist is not in action. A slot is cut and a hole drilled into this left over piece of material to further prevent rain and debris from getting into the hoist. This should be removed when using the hoist to raise or lower the tower.
The “Smoke Test”
Whenever making the first test of a piece of equipment or machinery, there is often a bit of anxiety or hesitation as to whether it will work properly or blow up in your face! I held my breath, plugged it in, and pressed the UP button and low and behold the tower lurched upward. Similarly pressing the DOWN button lowered it. This hoist is pretty speedy and I would probably prefer a slower travel rate, but it has sufficient power to lift the tower surely and steadily, and I’m confident that I will get many good years of service out of this installation. I will also be less likely to skip raising the tower for those Monday night nets and occasional contests with this new convience. I really love to work hard one time only so I can be lazy for the indefinite future!