In my quest to find a high gain antenna for my Alinco DJ-MD5TGP and my Hytera PD982G, I came across signalstuff.com. Their antennas are built by Hams in Utah (American Made) and proceeds go to hamstudy.org
I exchanged emails with Richard Bateman on this email. My main concern at the time is that both radios I mentioned above are 1) Chinese and 2) different size antenna SMA-M “Depths.” Being Chinese their design can very between manufacturer and can cause issues to end users.
Take a look at the picture below, you can see the depth of the Alinco and the depth the SMA-M sits in relation to the plastic of this case. its pretty deep and any antenna connector that does not have a recess can make this antenna connector a failure point.
I purchased Richard’s antennas for testing and to see which one will fit my 2 described radios. I purchased a BNC antenna with adapter and an SMAF antenna.
Upon receiving (EXCITED!) these antennas, unraveled them as they were all wound up in a nice package. Both came apart with ease and immediately went back to their natural straightened state. I first used the Alinco and did a few connection tests.
The first test was with the SMAJ antenna. I noticed that after mounting the antenna had quite a gap between the antenna SMA-M and plastic from this radio’s case. The issue that I would have is stressors on this connector against unusual forces may damage the radio connector over time. Using this antenna one would need to be extra careful not to make a mistake and drop it or place any tension on the antenna connector point inadvertently. the stock antenna does a great job in supporting the antenna while mated to the body of the radio. My other concern is comprising the water resistency. I realize the Alinco is only IP54, but this would even compromise that rating further.
From here I decided there is some room for improvement on this radio and was not comfortable using this antenna on the radio.
Next I tried the BNC Version on my Alinco.
With this configuration, it fit quite well and I was happy with the connection. Adding the gasket to the bottom of it created quite a bit of resistance to fully seat this connector. I opted to forgo the washer on this installation. A pair of pliers helped to provide the necessary tightness that the knurling on this BNC connector lacked to provide. This is not a fault with the connector but the radio’s design, I believe, does not provide a good adaptation to some aftermarket radios.
I personally like this setup and would like a quick disconnect that I can use in my vehicle for repeater work on DMR.
Now on to the Hytera.
I first attempted to connect the SMAF version of this antenna to the radio. I was concerned that this radio’s stock antenna SMAF and the Signal Stick SMAF would be too short to fully seat. On the right is the stock Hytera antenna and Left is the Signal Stick. you can see the difference in connector height. I am concerned that this antenna’s connector will not properly seat and make a connection into the radio.
I attached the SMAF first and noted that it did seat quite well but not to the standard the Hytera antenna does to the case of the radio. This could be a concern that again compromises the radio’s IP68 water resistancy rating. I would feel more comfortable with the antenna base being a little wider. Adding the rubber gasket was a failure and did not allow enough threads to catch the SMA-M connector on the radio.
I next tested the BNC format. This test really has nothing to do with the antenna it self but the BNC Connector it self. This does properly seat to my Hytera body with plenty of space, but adding a gasket makes it again fail to make any contact to SMA-M threads. I will plan on doing a test to ensure the connection will work as expected. I would prefer to see the connector a little longer on the SMAF side of the BNC.
I feel as though the SMAF connector version of this antenna may need some work depending on the radio. This would require changing the antenna 3D printed base slightly and maybe accommodate a gasket for extra water resistancy. I really like this antenna and what these Utah hams are doing for hamstudy.org. I would be happy to help them in any future development of their antenna. I wouldn’t mind seeing a shorter antenna! I invite Richard and his crew to collaborate with me if they would like to address and make any changes.
I know this is not the end-all / be-all of antenna reviews. I know there are some flaws with my testing since I don’t have every DMR Radio in my shack. With what I have and use on a daily basis, I feel this is a great review of this Super Elastic Signal Stick by Signalstuff.com with radios that I have at my disposal.
Stay tuned for a test of this antenna during Public Service events coming up!
Richard and I have been exchanging emails and he had some concerns with my review. I understand that water resistency is only a facade at times that nothing is ever water resistant, hence why the IPXX numbers are noted. I agree with his words that “Any,” aftermarket antenna can compromise that number if it does not fit well or anything for that matter. But with my fitment, the SMA-F has quite a bit of an antenna gap on the Alinco. the BNC, as you can see from the picture fits like a glove!
An RF test of this antenna wont be conducted in a “Lab setting.” I plan on doing some real world testing during an upcoming public service event. I will post the video when it is compiled.