Inverted U on 160, 80 and 30 and half square on 40M
Just for laughs, lets compare three antennas that I could have – against what I have now – the “Mod Bob”.
An Inverted L would be MUCH better than the Mod Bob. Its something I need to consider – because I could use the u.RAT to tune it.
On 80M, the Mod Bob seems to have the best take off angle by far, but the gain (loss) looks pretty bad.
On 40M, the inverted U is a half square and it is best out of the three
I had my friend Andreas, N6NU, model the Mod Bob vs. the Inverted L, and on 160M and 80M, the Inverted L is a clear winner.
His models are a little different than mine, but I needed to have this “peer review”.
The Mod Bob seemed to perform better than the models suggest, which show the Mod Bob as a cloud warmer. However, not all DX angles are low, especially during sunrise and sometimes at sunset.
I wish I could do an A-B test, but I can’t.
I think it’s time to convert the Mod Bob to an Inverted L, because 160M is the one band I really need, and both his model and mine match and tell the same story. I will use the u.RAT to control the tuning now that it will be an unbalanced vertical feed.
I do remember that when I had a Cushcraft MA160v that I feed it with just one variable capacitor and that’s all it took to tune it on 160M. I did this to avoid tuning the stinger at the top.
Ok, lesson to remember – ask a friend to peer review your antenna modeling!