TW-SDN1 Dual Band NMO Antenna

I purchased this antenna from TWAYRDIO as a 'quick fix' for a trusty old Maldol mobile antenna that was damaged in a storm. Fully expected it would get me out of a bind but would end up being replaced by another higher quality unit. Boy did I get surprised! Initial impression was that this antenna appeared to be a quality build with nice fit & finish. Those two factors lead me to believe the overall durability will be good and the antenna will hold up to life on the road over time. Being as I was replacing a damaged NMO antenna, installation was super simple and literally only took a few minutes to accomplish. Performance has been pretty good as SWR is 1.6 or lower across the 2M, 70cm, and GMRS bands. Reception and transmission are both (subjectively) lower by a slight amount than the old Maldol I mentioned but that antenna is no longer available and in fairness this antenna does all I need it to do for day to day radio hobby needs. If you're on the fence about this dual band antenna I would encourage you to give it a try. I'm impressed enough to not be concerned with replacing it and would recommend to a friend looking for a budget friendly option.

I have been a ham since 1973. This is one of the best out of the box mobile antennas I have ever bought. I installed with a low profile mag mount in the center of my Highlander roof. I tested both bands with a Comet CAA-500 Mark II antenna analyzer. The SWR is better than 1:4 across the entire band on both 2 meters and 70 cm. The antenna is a solid quality build with gold plated center contact, installed "O" ring and nice chrome finish. An Allen wrench is provided to install the whip. It is a good value at the price. If your looking for a new dual band mobile antenna, you have found it.

Overall good, especially for the cost. Initially the SWR was about 1.6:1 on 146MHz and 1.3:1 on 430MHz, and 2.6:1 on 440MHz After a few cuts taking 1/4"-3/8" off at a time with a hack-saw it got substantially better. I unfortunately went a bit too far but not by much. I think I took about 1 inch off (wish I stopped about 3/4" removed) and now it runs around 1.3:1 on 146MHz, 1.0:1 on 430MHz, and 2.3:1 on 440MHz. For the cost, I'm reasonably happy with the results.

Received on schedule and got the rod hex-screwed in place before the box hit the floor. I put this antenna onto my car's rear hatch/luggage rack mount and hooked up a NanoVNA to the feed line. Things look good. For 2 meters, it's flatter than flat with the highest reflection coming in at less than 1.2:1 with no adjustment. If I were still in CAP and able to use non-NTIA eqpt, this would have been more than wide-banded enough to handle a 5.5 MHz repeater split. SWR is a good thing to check but knowing as we do that even a 50 ohm resistor has a fantastic match, I have yet to test the actual field performance. Having dual radios on board for event work, it'll be convenient to compare this antenna to the long Tram, center-loaded antenna on the other side. I'll swap both antennas <---> radios the day I do this to keep it relevant. 70cm came in pretty well, to, with the highest in-band match at 1.6:1 at the very top of the band. I can live with this or I can nit-pick and take 1/4" off and see where it goes. We'll see, but again its going to be the real-world tests that matter.

Standing wave ratio 1.2 across 2m and 70cm, with the whip fully down on the coil. Note that it's on a heavily bonded 2015, aluminum body Ford F-150. Your mileage may vary.

I didn't have to cut mine to get good SWR on 2 m and 70 cm. I wish it also had 220.

This antenna was an absolute steal. It works as a tri-band antenna. 143-147mhz 1.2 swr, 443-446mhz 1.4 swr and 467mhz was 1.6 swr. Measurements were checked on a Rigexpert and mounted with on a Bulletproof Diesel 3rd break light NMO mount. I utilize Ham 2m/70cm frequency’s as well as GMRS. This antenna feels pretty durable and sits at 21” in hight. Im connected to handheld radio with 5 watts and hitting all the repeaters in my area. Before my transmit signal was not very clear from inside the vehicle. With this antenna I’m getting good feedback on my clarity. Im very happy with this purchase. I was leaning on getting a Scan-III for much more money. Dont be hesitant about the brand name or quality. This antenna will work.

I received this antenna today and immediately got busy testing it with my electronic instruments. To be 100% honest I was not expecting much but I was in for a pleasant surprise. I have this antenna mounted atop my large car roof with a TRAM NMO Mag Mount (see photo). So far this purchase has exceeded my expectations. The antenna came properly tuned for VHF and UHF amateur bands. VHF SWR is 1.04 : 1 and UHF is 1.51 : 1. After sweeping this antenna on a Vector Impedance Analyzer I think I may be able to get the SWR on UHF lower by removing ~ 3/8 of an inch from the element but the antenna is usable out of the box as-is. Nice item. I am tempted to purchase another one to keep as a spare or give as a gift. 73's. UPDATE: I trimmed 1/4" off the bottom and got the 70cm SWR from 1.51 down to 1.40. The 2 meter SWR stayed the same at an awesome 1.04. Cheers.

Great antenna, for the price and performance it's actually doing it's job quite well. I used it with a 5W Baofeng and was quite astonished with the range I was getting. Now she's permanently serving my 25w mobile radio with no problems at all.

I purchased to replace an antennae that had signs of corrosion. Much clearer RX and TX signal. I painted it after reading advice online and it works great.

Works

Fast shipper , great vendor. Works perfectly with my nmo mount!

Unit tests as >1.8:1 across 2m amateur band, exceeding 2:1 in places. Not tested on 70cm band. Very short, looks like primarily a 70cm antenna which can be forced into low power use on 2m. Only upside is, it's short.