Author Topic: Evaluating HT antennas by SWR?  (Read 701 times)

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GreekMan

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Evaluating HT antennas by SWR?
« on: August 04, 2017, 02:08:37 PM »
I wonder if this is a valid method.
Measuring their SWR over the bands' range

I have done it for quite a few already, but should I use these measurements a selection criteria?

spacecase0

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Re: Evaluating HT antennas by SWR?
« Reply #1 on: August 05, 2017, 12:51:27 AM »
I have done it when lacking other tools, and it got close enough

also used an HT with no output cutback with bad SWR, and watched heat made VS time transmitting, and tuned the antenna that way
it worked pretty well, also received better than anything else,
at least 3 of 25 or so antennas I sold about 25 years ago are still in use because they work so well (lost touch with most of the people I sold them to)
my guess is that I tuned for SWR, but adding the SWR meter never got the same results as it changed the geometry

GreekMan

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Re: Evaluating HT antennas by SWR?
« Reply #2 on: August 05, 2017, 07:49:34 AM »
and i also tune for SWR, even though i know that cable losses also mess with the antenna "tuning".
I got a 1.3 value for a dipole, which CANNOT happen.

Regarding my HT antennas' results I am too pressed for time to put them in a spreadsheet.
But they got scary some times. Like the original kenwood TH-F6 getting 17 or more in the VHF band,...

spacecase0

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Re: Evaluating HT antennas by SWR?
« Reply #3 on: August 06, 2017, 12:21:13 AM »
closest I have got to tuning to lowest heat value is using the FT817 front antenna connector with it's built in SWR meter (not good on 440 band)
if you are adding cables, you are only going to see horribly offending antennas,
past that you will likely have no clue what is going on.
"someone with one SWR meter will think they know what is going on, but someone that connects 2 or more will know they have no idea what is going on"

Tevin

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Re: Evaluating HT antennas by SWR?
« Reply #4 on: August 10, 2017, 07:14:41 AM »
If you mean rubber HT antennas, by default they all suck.

When measuring/evaluating them, all you are really doing is determining their suckiness, or to use a tasteless metaphor, you're looking for "the tallest midget in the room".

Some do work better than others, but because the conditions they are used in vary so much, what looks good in a lab or on your workbench may be very different in the real world.

I have a Diamond RH77CA that actually does perform well...for a rubber antenna! The catch is that it's about 15"/38 cm long and a somewhat floppy & unwieldy on an HT, especially when clipped to your belt. I mostly use it on my FT-817 and it will hit repeaters and simplex contacts that the lesser rubber antennas can't.




GreekMan

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Re: Evaluating HT antennas by SWR?
« Reply #5 on: August 10, 2017, 12:45:11 PM »
yep, i know...I have its competitor, a Midland one (thin whip)....

and indeed when i sit down and write an article on the testing is gonna be called "How bad is your Ht antenna?"

Tempstar

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Re: Evaluating HT antennas by SWR?
« Reply #6 on: August 13, 2017, 08:52:32 PM »
I'll weigh in on this one. Using an MFJ-226 my best rubber duck (Retech) is 1.2 on VHF and 1.8 on 446 UHF. It also works well on 450 mhz (Broadcast TV mobile use) at 1.6. I have one that was off the charts and most are in a box never to be used. I have a handful of Midland UHF with BNC connectors that are on the money. For the most part, the Baofeng and other chinese antennas are terrible. The one exception is the Wouxun KV-9dp (I think that's the model) that came with two antennas. The shorter one is 1.2 vswr and the long one is 1.3 on vhf, both return 1.6 UHF.
An interesting note when sweeping these antennas is that they are usually resonant on the intended band, telling me they are built by calculation rather than vswr testing.
"Preparedness is a lot more than just buying stuff"

GreekMan

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Re: Evaluating HT antennas by SWR?
« Reply #7 on: August 14, 2017, 12:08:40 PM »
surprisingly the Baofeng -5R stock antenna measured BETTER than the 2 counterfeit (discovered after purchase) ones that I have for it
Will have to do the same test for the -3R stock one