I know this thread is very old and Skirtchaser was talking about the Golden Rod 50, but I don't think it's produced anymore. There were lots of varying opinions made about the GR45, so this modeling demonstration is about this Original Signal Engineering mobile antenna.
So, below is my most current model of the GR45, and thanks to the help from DR_DX, a member on this forum...I was able to finally get the specs really close.
For convenience, I did make the Top Hat using 4 horizontal elements and adjusted the lengths to resonance...instead of making the Top Hat using two parallel elongated loops.
I made overlays for the 3 models posted below for comparison.
I made these models at 36' above Exnec's idea for Average Real Earth.
I did not include the mast in these models.
I also left the models showing maximum gain and angle at the default high angle lobe, and you can note that each model shows a different angle by 1* degree,
The maximum low angle lobe for each model is at 10* degrees, and all models are at the same angle down low. You can see the 1/4 wave GP still shows a little better gain at 10* degrees, which is probably what we might expect.
1. is titled .25 slanted radials RES 36'. It is a 1/4 wave whip on top of 4 x 108" slanted down radials for the ground plane.
2. is titled GR45 4SR Lee 36' and is over a 4 element GP as well. It is a model of the GR45 with dimensions provided me by Lee, DR_DX on this forum.
3. is titled GR45 4SR 36' and is over a 4 element GP too. This is an old model I made in 2015, and I wasn't far off with the dimensions back then.
If you have any questions, just ask.
