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View Full Version : What's a normal SWR for a handheld radio antenna?



calvarez
06-06-2016, 12:01 PM
This seems crazy bad.

http://i.imgur.com/QUHJ589.jpg

2equisYJ
06-06-2016, 02:36 PM
Assuming 2 meter/Vhf you should be <2.0 if you are not standing next to another source or large reflector.
Looks broke to me


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calvarez
06-06-2016, 02:52 PM
I tested a few other HT antennas and they measured out correctly, so this antenna seems bad. I also saw an Amazon review noting this problem from another buyer. I e-mailed Diamond, let's see what they say.

Oddly enough, it works well in the field and blows away the radio's stock antenna.

ltklein
06-07-2016, 06:56 AM
It's not looking good. Since it's a dual-band, did you check it's performance on the other band? I assume it doesn't change much when you hold it vertically and move into the clear (away from the car, house, etc)?

It would be interesting to see how a counter-poise would affect it. For our viewers, that would involve taking a length of copper wire the same length of the antenna, crimping a lug on the bottom that just fits over the SMA connector on the radio/meter. Put it on the connector and then tighten the antenna down over it. Let it hang down with the antenna up and you've just created the 2nd half of a proper di-pole.

It's not pretty but it does provide the proper ground plane and improves any of the HT mounted antennas. Ugly to use everyday but fun to try....it works...

calvarez
06-07-2016, 11:03 AM
I didn't check UHF, I really stick to VHF usage. It changes very little with orientation, though it changes a lot when brought close to large metal objects, as you might expect. Not a big change getting farther from the house, but if I get right up against the walls it moves.

I've been meaning to make a tiger tail anyway, that could be an interesting test.

No answer from Diamond yet.

ltklein
06-08-2016, 07:00 AM
Cool...do post up what Diamond says...will be interesting...

Was inquiring about the dual-band as it would indicate that perhaps the coil is shorted. When it shorts (sometimes the enamel insulation isn't done well) it throws the antenna way out of tune.

Though, bad is bad for whatever reason.

Thanks!

ltklein
06-08-2016, 07:00 AM
Cool...do post up what Diamond says...will be interesting...

Was inquiring about the dual-band as it would indicate that perhaps the coil is shorted. When it shorts (sometimes the enamel insulation isn't done well) it throws the antenna way out of tune.

Though, bad is bad for whatever reason.

Thanks!

calvarez
06-08-2016, 09:46 AM
I'll give it a test later today. No word from Diamond still.

ltklein
06-08-2016, 10:33 AM
You're out in the neighborhood of HRO.... Maybe they have one in store that they'd let you compare with...

There seems to be a love/hate relationship with them but they've always been ok to me...they own a fair bit of my wallet these days :)

Just a thought...

One guy smarter than me told me we can't trust SWR measurements on 2m and 440...but didn't explain himself. Only place I heard that, but didn't look into it any further.

lpennock
06-08-2016, 06:31 PM
An HT is designed to capacitive couple to your hand for ground. HT antenna are designed around this coupling. When you put on a analyzer you are changing ground so a lot of HT antenna don't test good.

Leonard Pennock (AD7AS)
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calvarez
06-09-2016, 12:49 PM
But shouldn't all antennas test the same way on the same analyzer?

lpennock
06-09-2016, 01:24 PM
Not necessarily. Depends on actual antenna design. Think about it like a mobile antenna for a minute. A 1/4 wave won't hardly work without a good ground but a 1/2 wave will work fine but have slightly elevated swr without a good ground.

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