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Nagoya Ut-72 Magnetic Mount antenna.


kidphc
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Here is a little review. Since I got the Nano VNA f I decided to test an antenna that I have had for a while. I had bought 2 for a road trip. Btech sells them for $29. They are a lot cheaper then buying a magnet NMO and nmo antenna. I have been happy with the 2m (144mhz) performance, It has ok performance with GMRS and I feel it has been meh with 70cm (444mhz) performance. So I wanted to see what the numbers were like as far as SWR. I have been mostly using it for repeater usage on 2M and GMRS. No luck on 2m simplex, FRS/GMRS works well for simplex when in range. Furthest GMRS repeater has been to Alexandria give or take 11 miles from the truck. The same antenna, is being tested on a cookie backing pan in my dining room connected to an FT991a. I have managed to connect to 2m Frederick MD repeaters which are 27+ miles away on 5 watts. Still can't make a simplex call 5 miles with the same setup running 30 watts.

 

The stats from BTech 's website:

https://baofengtech.com/NAGOYA-UT-72

 

  • Frequency Range: 136-174MHz, 400-520MHz; Optimal Frequency Range: 140-170MHz, 420-470MHz
  • Wave: 1/4λ (144MHz) - 5/8λ (430MHz)
  • Gain: 3.5dBi
  • Max power: 80 Watts
  • VSWR : Less 1.5:1
  • Impedance: 50 OHM
  • Connector: SMA-F & PL-259
  • Length: 20 inches

 

So the VNA is showing the following.

 

144.562 National 2m    SWR 2.53 :1

144.000 MHz                SWR 2.89:1

147.999 MHz                SWR 2.21:1

159.300-163.500 lowest SWR of 1.18:1

 

 

420.000                         SWR 1.92:1

450.000                         SWR 1.33:1

444.900-445.800 lowest of SWR of 1.3:1

 

FRS/GMRS Frequencies

462.5625                       SWR 1.35:1

467.7250                       SWR 1.40

 

SWR was 1.35-1.38:1 for most of the FRS/GMRS band.

 

Lowest actually was at 1.27:1 at 464.575 - 465.763 MHZ well outside of Amateur radio and FRS/GMRS service allocations.

 

 

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Nice review! I would stay away from VHF while using it. 3:1 is almost guaranteed damage to your radio and that is pretty close.

yeah. Not keying up with the ft991a any more on vhf. The baofeng, well its a baofeng and a ht.... so I will be pounding the ptt.

 

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Here is a little review. Since I got the Nano VNA f I decided to test an antenna that I have had for a while. I had bought 2 for a road trip. Btech sells them for $29. They are a lot cheaper then buying a magnet NMO and nmo antenna. I have been happy with the 2m (144mhz) performance, It has ok performance with GMRS and I feel it has been meh with 70cm (444mhz) performance. So I wanted to see what the numbers were like as far as SWR. I have been mostly using it for repeater usage on 2M and GMRS. No luck on 2m simplex, FRS/GMRS works well for simplex when in range. Furthest GMRS repeater has been to Alexandria give or take 11 miles from the truck. The same antenna, is being tested on a cookie backing pan in my dining room connected to an FT991a. I have managed to connect to 2m Frederick MD repeaters which are 27+ miles away on 5 watts. Still can't make a simplex call 5 miles with the same setup running 30 watts.

 

The stats from BTech 's website:

https://baofengtech.com/NAGOYA-UT-72

 

  • Frequency Range: 136-174MHz, 400-520MHz; Optimal Frequency Range: 140-170MHz, 420-470MHz
  • Wave: 1/4λ (144MHz) - 5/8λ (430MHz)
  • Gain: 3.5dBi
  • Max power: 80 Watts
  • VSWR : Less 1.5:1
  • Impedance: 50 OHM
  • Connector: SMA-F & PL-259
  • Length: 20 inches

 

So the VNA is showing the following.

 

144.562 National 2m    SWR 2.53 :1

144.000 MHz                SWR 2.89:1

147.999 MHz                SWR 2.21:1

159.300-163.500 lowest SWR of 1.18:1

 

 

420.000                         SWR 1.92:1

450.000                         SWR 1.33:1

444.900-445.800 lowest of SWR of 1.3:1

 

FRS/GMRS Frequencies

462.5625                       SWR 1.35:1

467.7250                       SWR 1.40

 

SWR was 1.35-1.38:1 for most of the FRS/GMRS band.

 

Lowest actually was at 1.27:1 at 464.575 - 465.763 MHZ well outside of Amateur radio and FRS/GMRS service allocations.

You want to really have some fun try testing some HT antennas! They're not easy since the radio, and part of your body, ends up as part of the antenna. When you see the results you'll wonder why they work at all. A few I've tested belong in a landfill somewhere.

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I know to get accurate numbers its difficult. So I won't be doing any soon. As long as the antenna is equal to or greater then a dummy load I am good.

 

I should say I don't mind as much since most hts can handle the higher swr.

 

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Yes correct. Miss info mis type no difference it was the wrong info.

 

The info I typed turns out was for proposed c4fm national simplex calling. Which apparently there 3 different frequincies.

 

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I know to get accurate numbers its difficult. So I won't be doing any soon. As long as the antenna is equal to or greater then a dummy load I am good.

 

I should say I don't mind as much since most hts can handle the higher swr.

It's still would be an interesting experiment. Stories surface about counterfeit antennas from at least one well known manufacture are out there. I think it is Nagoya. Antenna testing showed the difference between the real one and the fake. 

 

https://www.eham.net/reviews/view-product?id=7741

 

On another point I have purchased a few "cheap" magnet mount antennas mostly to get the mount from Ham Radio flea market vendors. After testing them the performance was nowhere close to the spec's on the package.

 

Some antenna testing results.

 

http://www.km4fmk.com/AntTesting.html

 

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Ok. First off. I do not know how to property test Ht antennas. A calibration was done with the SMA extension for each frequency band when changed. All antennas are authentic from what I can tell. The Nagoya's are from Btech and the Abree is from Abree.

 

Nagoya 701c

 

144.000      1:1.38

146.460      1:1.15

147.999      1:1.32

 

420.000     1:2.06

450.000     1:2.21

 

462.5625    1:2.15

467.7250    1:2.13

 

Nagoya 771

 

144.000      1:1.23

147.999      1:1.50

 

420.000     1:1.55

450.000     1:1.14

 

462.5625    1:1.37

467.7250    1:1.45

 

Abree 42"

 

144.000      1:1.55

147.999      1:2.02

 

420.000     1:1.55

450.000     1:1.84

 

462.5625    1:2.24

467.7250    1:2.38

 

There was a big difference between holding the coil of the antenna(base) and the lead. Unfortunately, it isn't like an MFJ analyzer where I could screw it into. So I chose to hold them by the coil except for the Abree. Holding the Abree by the coil it would go from 1:1.55 and then jump to 1:6.63. Even laying the antennas on the table it would jump by quite a bit. Try holding a 42" antenna by the SMA lug, my fingers hurt.. Again take this with a grain of salt.

 

Should add, for GMRS the 701c is the one I would go with. The 771 works but I perfer the 701c. The Abree rocks for 2m.

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Yes. The recieve has been better when I have added cattails. It works best when you get it close to the 1/4 wave of the frequency in use. I had the best results with 2m with a 19" cattail. The abree made no difference with the cattail. I believe it is due to the coil at the base of the antenna. Which looks to be the counterpoise.

 

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  • 9 months later...

Similar issues, authentic Nagoya UT 72 after buying a counterfeit from Walmart. The difference was pretty stark. But my handheld eight watt running a diamond Rh 77 CA, inside the car outperformed  the Nagoya mag mound by over a quarter mile in an suburban environment .

 

Yes I know the superstition that sitting inside the car with an antenna leaning against something or held in the hand will have it signal impeded by the metal in the car.

 

But you know what they say about being told it’s raining when it’s  yellow. Ran multiple tests multiple antennas multiple sources and the handheld diamond 16 inch transmitting 462 where outperformed the 19 in Nagoya UT 72 on the center of the roof on my SUV.  And no, the SUV does not have luggage racks.

 

I do plan on getting a SWR meter and trying to tune it, I bought three and send them back because quite frankly he just didn’t even work.  Spend less than $100 on an SWR meter and you just wasted $100

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Similar issues, authentic Nagoya UT 72 after buying a counterfeit from Walmart. The difference was pretty stark. But my handheld eight watt running a diamond Rh 77 CA, inside the car outperformed the Nagoya mag mound by over a quarter mile in an suburban environment .

 

Yes I know the superstition that sitting inside the car with an antenna leaning against something or held in the hand will have it signal impeded by the metal in the car.

 

But you know what they say about being told it’s raining when it’s yellow. Ran multiple tests multiple antennas multiple sources and the handheld diamond 16 inch transmitting 462 where outperformed the 19 in Nagoya UT 72 on the center of the roof on my SUV. And no, the SUV does not have luggage racks.

 

I do plan on getting a SWR meter and trying to tune it, I bought three and send them back because quite frankly he just didn’t even work. Spend less than $100 on an SWR meter and you just wasted $100

Currently, it's attached to my ac unit and ft991a. Shielded by the aluminum siding of the house. Getting reception from a repeater some 30+ miles.

 

On the truck/van it worked. Wasn't thrilled with the performance.

 

But to throw on my wifes van and get 5 miles is ok with me. On my truck I am running a larsen 2/70. Not optimized for gmrs, gets kinda high in swr at that frequency. But I don't care if it blows up the baofeng. It served its purpose. Might get an STI flexible whip for gmrs on my truck.

 

BTW the sma to so239 adapter cat tail is garbage. The ones packaged with them. Had 3 where the center just slipped out of the sma connector. Using sma/239 solid adapter, much better.

 

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  • 3 weeks later...
  • 4 months later...

I have a Midland 5/8 wave on a mag mount stuffed up in a closet mag mounted on an 8"x12" piece of sheet metal and it works fairly well, at least to a couple repeaters 30 and 60 miles out.

A round pizza pan or a file cabinet will work; some swr testing I did the other day used the top of a chest freezer, though I didn't test range on that.

Granted, indoors isn't the BEST situation, but it can work fine, depending on the building materials. Wood and drywall block a lot less than metal, concrete and radiant barrier.

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  • 9 months later...
On 7/27/2021 at 12:59 AM, jgbeall said:

Out of curiosity, if I used the UT-72 indoors with a mobile GMRS 50W radio, what size metal base would be needed to be effective?

Or, am I dreaming?

you will need something ~6-12" for the ground plane... stay clear of the antenna with that power output too, when transmitting.

YMMV

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Ace Hardware stocks sheet steel in different sizes and thicknesses. I use a 2 foot x 2 foot piece for both GMRS and 2 meter ham work with a 50W radio. Exposure to RF is an issue you need to guard against. There are calculators available on the web that allow you to find the safe distances for both you as the operator and an observer. 

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  • 4 weeks later...
On 5/23/2022 at 8:03 PM, WRQW695 said:

I found out from Katy @ Baofengtech that the newer UV-72G is the old broadband UV-72.  The new UV-72 is more ham tuned.

Good to know, as I am currently torn between purchasing one or the other for GMRS!

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