In this document, I look at using portable transceivers in the home environment where establishing a permanent shack isn’t possible or necessarily desirable. I prefer to make-do with what I’ve got, which enables me to get going almost anywhere, avoiding permanent installation.
To read the whole document click this link.
W5AWS / Andrew:
Thanks for the detailed report on your findings for your dual-band antenna. I have the Diamond NR770HNMO which is the NMO version of the same antenna and I specifically chose it because it is radialless which would go well fender-mounted on my Jeep JT which body is a combo of plastic, fiberglass, aluminum, and steel. While I am satisfied with the actual performance of the antenna with my HT at 5 watts, I too noticed the SWR was higher than advertised on the UHF band. I checked the antenna’s SWR after I installed it with a NanoVNA and had readings very similar to yours on the freqs of 440 to 450 MHz. I didn’t record the actual readings but since my signal reports are good on both bands I just figured maybe my antenna had this reading due to the fender mount. After reading your report it definitely appears Diamond needs to re-check their specs.
One more observation, when taking a quick wide-band sweep of the antenna with the NanoVNA, I noticed the 220 MHz band had better SWR than the 440 MHz band, even thought the antenna is not listed as a tri-band. I’m now curious what your SWR is at 220 MHz. Maybe we actually have mislabeled tri-band antennas?
Sincerely,
Chris Elliott – W5CAE
W5CAE / Chris,
I’ve just noticed your recent comment while browsing the web-site before this evening’s net. It is good to know that you get results similar to mine yet with different test equipment.
I will try scanning my antenna across the 1.25m band and post what I find here.
Andrew — W5AWS.
After the TARC Net this evening, I swept my Diamond NR770HA across the 1.25m band with my analyzer. SWR was flat across the band at about 4.30:1, which is quite a bit more than I got on 70cm. I took a screenshot that I will send to the webmaster for inclusion here.
–Andrew, W5AWS.