Nagoya Ut-72 Magnetic Mount antenna.

[WSEA915]

On 5/9/2020 at 8:10 PM, kidphc said:

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.

 

 

Realizing this is a really old post, I would suspect this is a ut-72G antenna, which is cut for Murs and GMRS.  The swr sweet spots are right in the range for those two services.  The 72G is cut a couple inches shorter than the 72 which is the amateur version of this antenna, so one woul expect SWR in the lower frequency neighboring ham bands to not be good.  If you look at the specs for both antennas the difference in the tuned frequencies is obvious, and matches your test results pretty clearly.  

If you ordered the 72g, the gmrs version, then the results are expected.  If you ordered the 72, the ham version then I would look up the specs on both, measure the radiating element and see which one you actually got.  My money is it's the GMRS version.