SG7500A SWR Scans - 2.jpg
I picked up a Diamond SG7500A dual band antenna to use on my new vehicle. It's a 1/2 wave design so it shouldn't need a ground plane.
It's going to be installed on the roof rack. Since there isn't going to be much if any ground plane I wanted to see how much of a difference it would make. I did two sets of tests, no ground plane, and with a set of ground radials bent at a 45 degree angle. The addition of the ground radials made a very noticeable difference in the SWR scans. The no ground plane scans look OK but seems to be biased a bit towards the higher frequencies. That can be adjusted with a small change in length of the bottom element. There are set screws there for this purpose, however the manufacture claims it's "factory" tuned.
I was hoping the bandwidth might be high enough to cover the Ham bands along with MURS / GMRS. Ah, maybe with some tweaking if the vehicle installation approximates the ground radial test setup enough.
Misc. Radio Gear
- 28 images
- 1 comment
- 15 image comments
There are no comments to display.
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.