Ham install -- on a Prius

jblc

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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 :p 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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Toytec

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I have nothing for you on this one, except place a larger fully charged 12V battery next to the starter battery and move your direct connect wire over to it. (just to test)
When keying the mic it may be too much for the little guy.
 
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Trigganometry

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Having dabbled in radio in my past what most miss when cobbling together their rigs is not properly ’matching’ the antenna to the base units. This can actually be detrimental way more than most think!

Most manufacturers will recommend certain masts for their radios. That’s the reason behind it!
 
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jblc

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Thanks all.
On further reading, the smaller battery should still be able to support a 50W rig without issue.


... when cobbling together their rigs is not properly ’matching’ the antenna to the base units. This can actually be detrimental way more than most think!

Most manufacturers will recommend certain masts for their radios. That’s the reason behind it!
Interesting, thanks. I've read of several successful installs though, with this specific antenna. Also, since SWR is low, doesn't that mean it's good to go? (Also, I didn't see any recommended antennas in the manual)

Any other thoughts (from anyone) appreciated!
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