I have a triband HT antenna that claims to be an ABBREE AR771. I ran a quick and dirty test with it mounted to the nanoVNA and held in my hand as one would hold a HT. All three bands were low at the SWR dip but best case SWR on 220 clocked in at about 1.5 while 144 and 440 were up around 2.6 best case. But then antenna matches for hand held devices are moving targets anyway and it is truly amazing how much abuse the final transistors in these things can take.
The thing works on the $40 radio I got it for so I'm happy. I haven't done much in the way of real world testing as this is just a beater/backup radio anyway.
73
-Jim
NU0C
On Sun, 21 Feb 2021 17:46:27 +0000
"David Eckhardt" <davearea51a@...> wrote:
I have tested a few tri-band antennas using an HP VNA. The antennas were
mounted in the middle of a large copper plane about 3-feet square.
Typically, most are good on only two of the three claimed bands. 220 is
usually the loser. However, I have found one and only one that exhibits a
good match on all three bands. That is the Diamond SRH320A. Of course, a
good match does not necessarily indicate a good radiator.
Dave - W?LEV
On Sun, Feb 21, 2021 at 5:23 PM <davidb1stein@...> wrote:
Here is a quick check - put the 50 ohm load that you used for calibration
and run the same scan as you did for the tri-band antenna. I have had
several dual band and tri-band antennas over the years and have generally
found the dual band will have acceptable VSWR on both bands, but the
tri-bands will generally be ok on 2m/440 and high on 220 or ok on 2m/220
but high on 440. I suspect that for VHF/UHF tri-band antennas to work well
on all three bands is not an easy thing to do.
--
David S
Jim Shorney
