The DBJ-UHF base repeater antenna is an omni-directional gain antenna for UHF without Radials. It was designed and patented by Dr. Ed Fong (WB6IQN). The antenna was originally developed under a grant from AC Daugherty Inc. for a MESH network.
Dr. Ed Fong, or one of his graduate students, personally makes every antenna. It is custom built and tuned to the buyers desired transmit frequency. The antenna comes with a lifetime “no questions asked” warranty. Simply return it for repair or replacement.
DBJ-UHF Base Repeater Antenna Specifications
Here are some of the main specifications of the DBJ-UHF Base Repeater Antenna:
440 MHz – 470 MHz Frequency Range
10 MHz Bandwidth
50 Ohm Impedance
75 Watts Maximum Power
SWR less than 1.3:1 over a 5 MHz Bandwidth. Less than 1.5:1 over 10 MHz bandwidth.
The DBJ-UHF Base Repeater Antenna requires some minor assembly. You will only need to purchase a 10 foot stick of 3/4″ 200 psi pvc pipe. Silicon is optional.
Note: Schedule 40 PVC cannot be used. You can purchase the 200 psi pipe from Lowes.
Cut a section of the pipe off at about 4 1/2 feet and clean the edges. The instructions say 4 feet, but I found that is just not long enough. The top of the antenna gets pushed into the top pvc cap.
Slide the antenna into either end of the pvc pipe and push the cap onto the pipe.
Make sure the antenna is not sticking out the other end of the pipe, and place the top cap on.
If you are going to use a sealing silicon, apply a thin layer to where both the top and bottom caps meet the pipe.
That’s it. The DBJ-UHF Base Repeater Antenna is now assembled and ready to mount.
Mounting the DBJ-UHF Base Repeater Antenna
The bottom 10 inches of antenna is coax. This is where you want to place your mounting clamps around the pipe. Hose clamps, “U” clamps, mast mounting clamps, or any other type of clamp may be used. As with any vertical antenna, it is important to make sure the antenna is mounted exactly straight up and down.
My recent purchase of eBay antenna is working out very well. I was wondering if there is a way to buy a collinear antenna. Currently reading an article from http://www.rason.org/Projects/projects.html where they have a homebrew coax collinear design posted.
It looked interesting to me with a 9 DB estimate. Uses a PVC covering as well. No details on the effect of the PVC velocity in the article.
Dr. Ed Fong, or one of his graduate students, personally makes every antenna. It is custom built and tuned to the buyers desired transmit frequency. The antenna comes with a lifetime “no questions asked” warranty. Simply return it for repair or replacement.
The DBJ-UHF Base Repeater Antenna requires some minor assembly. You will only need to purchase a 10 foot stick of 3/4″ 200 psi pvc pipe. Silicon is optional.
Note: Schedule 40 PVC cannot be used. You can purchase the 200 psi pipe from Lowes.
Reserved.
Does Ed make any HF antenna’s?
I do not know the answer to that. You can contact him to ask. He is very friendly based on my limited contact with him.
Dr. Fong,
My recent purchase of eBay antenna is working out very well. I was wondering if there is a way to buy a collinear antenna. Currently reading an article from http://www.rason.org/Projects/projects.html where they have a homebrew coax collinear design posted.
It looked interesting to me with a 9 DB estimate. Uses a PVC covering as well. No details on the effect of the PVC velocity in the article.
Thanks
Bill WA9NGF