WDØM - Pagosa Springs, CO

Pagosa Springs, Colorado

Adding 30 and 40 Meters to the 4 Element SteppIR
Continued

First the good news. After removing the old driven element EHU, I checked the condition of the antenna in general, having had it in the air for nearly 3 years. The climate in southwest Colorado can be extreme. With the 7500 foot elevation and nearly 330 days a year of intense sunshine, the UV rays can deteriorate plastics and rubber very quickly. I was happy to see that the EHU and the rubber boots for the fiberglass tubes were in excellent shape. The fiberglass tubes showed slight discoloration, but there were no effects of UV to be seen.

This is the old driven element EHU that was removed to make way for the new EHU from the "MonstIR" antenna to provide 40 and 30 meter coverage in addition to the present bands. The boots had been exposed to the Colorado sunshine and intense UV rays for three years. Despite the exposure, they all looked to be in very good condition with no signs of deterioration.

After removing the old EHU, I installed the new one. The new EHU is shaped slightly differently than the old one to accommodate the extra length of the copper-berylium (Cu-Be) tape. As a result, several of the mounting bolts that were used on the old unit are not used on the new one.

After installing the new EHU, the element return tube has to be installed 25 inches from the driven element EHU. Care must be taken to place the support so that it is level with the rest of the EHU mounting brackets. I figured out a way to do that by using a chalk tape from home construction projects to "snap a line" between the center of the driven element EHU, and the bolt that holds the support truss for the boom.

By locating one end of the chalk line at the center of the driven element EHU, and the other at the center of the boom support truss bolt, I found the absolute top of the boom and "snapped a line". I placed the ERT bracket under the boom, clamped it in place, then measured the distance between the sides of the EHU and divided by two. By splitting the distance, the ERT bracket was centered on the boom and I could drill the holes through the sides of the boom to hold it in place.

The next step in the process was where I encountered a problem with the parts provided by SteppIR. The ERT mounting bracket bolts they provided were half an inch too long, resulting in my having to buy two more stainless bolts that would fit. My guess is that the bolts were intended for a 3 element SteppIR, which MAY have a thicker boom, since it is mounted at the center of that antenna. The 4 element boom tapers at that point to a smaller diameter.

Continued on the next page.
Back to the previous page.


This is the old driven element EHU that was removed to make way for the new EHU from the "MonstIR" antenna to provide 40 and 30 meter coverage in addition to the present bands.	The boots had been exposed to the Colorado sunshine and intense UV rays for three years. Despite the exposure, they all looked to be in very good condition with no signs of deterioration.

After removing the old EHU, I installed the new one. The new EHU is shaped slightly differently than the old one to accommodate the extra length of the copper-berylium (Cu-Be) tape. As a result, several of the mounting bolts that were used on the old unit are not used on the new one.
	After installing the new EHU, the element return tube has to be installed 25 inches from the driven element EHU. Care must be taken to place the support so that it is level with the rest of the EHU mounting brackets. I figured out a way to do that by using a chalk tape from home construction projects to "snap a line" between the center of the driven element EHU, and the bolt that holds the support truss for the boom.
By locating one end of the chalk line at the center of the driven element EHU, and the other at the center of the boom support truss bolt, I found the absolute top of the boom and "snapped a line". I placed the ERT bracket under the boom, clamped it in place, then measured the distance between the sides of the EHU and divided by two. By splitting the distance, the ERT bracket was centered on the boom and I could drill the holes through the sides of the boom to hold it in place.
	The next step in the process was where I encountered a problem with the parts provided by SteppIR. The ERT mounting bracket bolts they provided were half an inch too long, resulting in my having to buy two more stainless bolts that would fit. My guess is that the bolts were intended for a 3 element SteppIR, which MAY have a thicker boom, since it is mounted at the center of that antenna. The 4 element boom tapers at that point to a smaller diameter.
Continued on the next page. Back to the previous page.