jblc
Well-Known Member
- Thread starter
- #1
There's a sizable number of ham operators on here, so I'm hoping for expertise or thoughts
I have an unexpectedly low transmission distance from a vehicle-mounted system, despite nominal 50W output. Summary: the vehicle can hear a low-power handheld, but the handheld can't hear the vehicle at that same distance.
(I'm licensed as well, to put folks's minds at ease about operating amateur radio.)
I did an install in a family prius (2010 model year): Icom 2730A w/ Nagoya UT-72, wired directly to the rear (starter) battery. The Prius starter battery is a bit smaller than that of standard vehicles.
The antenna is on the back left roof.
SWR at 50W with two different digital meters is <2.
The cable doesn't seem kinked/compressed.
1) For the tests, i'm communicating on 2m (simplex) with an inexpensive handheld (Baofeng BF-F8HP) + 42" folding antenna (SWR ~1.9). This is intentionally testing to a handheld, vs repeater etc.
2) With the handheld outside in the street, with the vehicle several miles away, the vehicle can hear handheld transmissions despite its low <8W.
However, far below this, beyond ~2 miles, the handheld can NOT hear the vehicle with its full 50W output. I can hear the Icom fan on tx (it's working hard), and Icom is verified set at High output.
3) Despite being 50W, the vehicle-->HT distance is both far lower than the dinky HT-->vehicle distance...and the vehicle also should be transmitting easily >10 miles, if not further.
Any thoughts on how this can be, and what to check next? Everything standard (that i know of) seems in order. Thanks
I have an unexpectedly low transmission distance from a vehicle-mounted system, despite nominal 50W output. Summary: the vehicle can hear a low-power handheld, but the handheld can't hear the vehicle at that same distance.
(I'm licensed as well, to put folks's minds at ease about operating amateur radio.)
I did an install in a family prius (2010 model year): Icom 2730A w/ Nagoya UT-72, wired directly to the rear (starter) battery. The Prius starter battery is a bit smaller than that of standard vehicles.
The antenna is on the back left roof.
SWR at 50W with two different digital meters is <2.
The cable doesn't seem kinked/compressed.
1) For the tests, i'm communicating on 2m (simplex) with an inexpensive handheld (Baofeng BF-F8HP) + 42" folding antenna (SWR ~1.9). This is intentionally testing to a handheld, vs repeater etc.
2) With the handheld outside in the street, with the vehicle several miles away, the vehicle can hear handheld transmissions despite its low <8W.
However, far below this, beyond ~2 miles, the handheld can NOT hear the vehicle with its full 50W output. I can hear the Icom fan on tx (it's working hard), and Icom is verified set at High output.
3) Despite being 50W, the vehicle-->HT distance is both far lower than the dinky HT-->vehicle distance...and the vehicle also should be transmitting easily >10 miles, if not further.
Any thoughts on how this can be, and what to check next? Everything standard (that i know of) seems in order. Thanks
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