For those who use handheld radios (GMRS or Ham Radio) are familiar with Nagoya and their super popular $20 Nagoya 771 antenna which spawned so many clones by other companies trying to capitalize on the popularity of the Nagoya 771.
Known for their quality but very affordable antennas, today I am reviewing the Nagoya NMO-HDC Heavy Duty Commercial (150-174 MHz/455-470 MHz) Antenna. This is an official Nagoya antenna sold by BTECH and is a a dual band antenna.
The height is about 47.2 in size and is great for mobile or base station installations.
The antenna supports up to 200W of power and the antenna has a 135 mph wind rating and this antenna requires no ground plane required. It’s well constructed and but of course, it all comes down to SWF.
Do know that this antenna also comes with mounting brackets and an NMO to UHF connector (the connector on the antenna is a SO-239 adapter, so you can connect to 50 ohm coax cable with a PL-259 ie. UHF Connector). So, find yourself a good RG8x Coaxial Cable with PL259 Male. At the radio end, you will need an adapter.
Now, it’s important to note, you are going to see differences of opinion, those who have the devices to measure SWR (Standing Wave Ratio). This is important because they can see if power coming from the radio is traveling through the antenna system correctly. If it’s poor for transmit and receive, then it can damage your radio. So, when the signal does not travel through the antenna correctly, the transmit power is reflected back to your radio. Thus the reason why you will notice people discussing the SWR for this antenna.
You definitely want to have a meter to read your SWR levels. So, if you plan to use this heavy duty antenna, you may want to invest in a meter that can read SWR levels.
It’s ideal to have SWR under 1.5. An SWR of 2.0-2./4 won’t damage your radio but anything over 2.5 is not good. Never transmit if the SWR levels are over 3.0.
I was testing out various sizes of coaxial and SWR was high on both. Tested with my NanoVNA and another device and SWR was high. It’s important to note that I was testing with shorter coaxial and the one I usually test with Nagoya (my 50 ft. is currently up the roof right now). So, testing the cables that I have and positioning is important but SWR ranged from 1.7 to up to 9 and most of the time it was over 3. Technically this is not good but because this is such a large antenna and will need to be mounted higher and tested, the high SWR, I’m not going to say “bad antenna” but more of bad positioning and wrong cabling for now.
But the SWR on my initial tests were high and feel I need to do further testing because this is not what I expect from a Nagoya antenna and I have an NMO-HDG which performed well.
So for now, I need to do further testing. Again, tried two different Nano devices and two coaxials, but still testing for now.
