n4dbm
Newbie
- Joined
- Jun 9, 2018
- Messages
- 37
Greetings,
I know how to do the math and I am fully aware of how a 3 dB change doesn't make a very noticeable difference in the field, but I need some real-world experience. I have played with UHF power amplifiers, going from 50 watts to 100 watts for example on this station is certainly not worth the effort when it comes to my observations out on the road while working the repeater.
I have a DB420 at 150 feet, top mounted, up in the clear, with very flat terrain. I am used to the coverage area, know where it gets noisy and where it stops.
The aging DB420 from the late 80's has finally developed duplex noise, probably a joint going bad. I am all about reducing wind-load on the tower. I have a new DB408 ready to go, which, in lab conditions has 2.6 dB gain less than the DB420.
My common sense and rational mind say that losing 2.6 dB will be a very slight, detectable difference on the road out in the field, but my memory from 20 plus years ago when I did this same change on another repeater tells me different. It "seems" to me the DB420 worked much better than the 408, despite the figures that say in all reality, it shouldn't. Maybe psychologically, all the effort 20 years ago to change the antenna to one "twice its size" made me at least think it was performing better, but was it all in my mind?
I need real-world experience input from anyone who has changed a DB408 to a DB420 (or the other way around) and tell me your observations. Thanks much.
I know how to do the math and I am fully aware of how a 3 dB change doesn't make a very noticeable difference in the field, but I need some real-world experience. I have played with UHF power amplifiers, going from 50 watts to 100 watts for example on this station is certainly not worth the effort when it comes to my observations out on the road while working the repeater.
I have a DB420 at 150 feet, top mounted, up in the clear, with very flat terrain. I am used to the coverage area, know where it gets noisy and where it stops.
The aging DB420 from the late 80's has finally developed duplex noise, probably a joint going bad. I am all about reducing wind-load on the tower. I have a new DB408 ready to go, which, in lab conditions has 2.6 dB gain less than the DB420.
My common sense and rational mind say that losing 2.6 dB will be a very slight, detectable difference on the road out in the field, but my memory from 20 plus years ago when I did this same change on another repeater tells me different. It "seems" to me the DB420 worked much better than the 408, despite the figures that say in all reality, it shouldn't. Maybe psychologically, all the effort 20 years ago to change the antenna to one "twice its size" made me at least think it was performing better, but was it all in my mind?
I need real-world experience input from anyone who has changed a DB408 to a DB420 (or the other way around) and tell me your observations. Thanks much.