The Chameleon URT-1 is a remote outdoor antenna tuner for almost any type of antenna or model of transceiver. This wide range tuner matches resonant and non-resonant wires, verticals, and long wire antennas with its range of 5 to 1500 ohms of impedance. The URT-1 has a 50 ohm coaxial port and a wire beehive connector for added versatility. And the unit is weather proof so it can be mounted outdoors near the feed point of the antenna.
Chameleon CHA URT-1 https://chameleonantenna.com/shop-here/ols/products/cha-urt-1
What are remote tuners
The purpose of an antenna tuner is not to ‘tune’ your antenna, but instead to provide a proper impedance match to your transceiver. Modern transceivers require a 50 ohm impedance and if there is a mismatch, the transceiver will respond, at the very least, by reducing output power, and at the worst, damaging the final amplifier components. So in order to deliver all available power to your antenna, a proper impedance match is required. This is a simplistic explanation, but sufficient for today.
Usually the tuner, either manual or automatic is placed near the transceiver. This is fine in most cases. If your feed line run is short, it won’t make a difference. But coaxial cable does introduce losses into the antenna system and if your antenna has a high impedance at the feed point, the mismatch will create standing waves, and the elevated SWR can be characterized as power lost in the feed line. Again that’s a simplistic explanation.
So how do we increase the overall efficiency of our antenna system? One method is to move the antenna tuner from the transceiver over to the antenna feedpoint. Situating the tuner at the antenna allows it to deliver the proper impedance match, which will be 50 ohms, to the feed line. Since impedance is matched at the coax, we can run longer pieces of cable without fear of losing energy due to high SWR on the cable.
Now remote tuners are typically used with non resonant antennas, either long wires or verticals. A resonant antenna, like a dipole or end fed half wave should have close to a 50 ohm impedance at the feed point. The tuner located at your transceiver will be used to fix slight mismatches or to extend the bandwidth of your antenna. Remote tuners would be overkill in these situations.
But with, say a 43 foot vertical antenna, the impedance may be between 400 – 900 Ohms. A 9:1 transformer could help knock that down, but using a remote tuner instead, will take whatever impedance the antenna is and deliver a consistent 50 ohms to the feed line, reducing overall system losses.
URT-1 Specifications
The URT-1 covers 1.8 to 54 Mhz and has 16,000 memories for quick recall when tuning. It can match any antenna with an impedance of 5 to 1,500 Ohms. That’s like a 30:1 match. And it can handle up to 125 watts sideband or CW and 60 watts on the digital modes.
Opening up the box, things may look a little familiar. This tuner is custom manufactured by Mat Tuner for Chameleon. It does look very similar to their MAT 40 remote tuner, but there are some key differences.
The tuner comes in two parts, the first is the coupler box. This connects to the transceiver and to a 12 volt power source. Then your coax cable runs all the way out to the tuner box which sits at the antenna feed point. You will notice that there are not separate control cables for the tuner. Power and tuner control are fed through the coax cable by way of a Bias-T circuit. The benefit to that is that you don’t have to run a second cable to the tuner unit, but the downside is that you need to initiate tunes by pressing the tuning button on the coupler.
The tuner unit is constructed out a aluminum alloy and it weather proof. On the top of the unit is a beehive connector for feeding wire or vertical antennas. On the bottom is a counter poise and ground connector along with two UHF female connectors. One UHF connector connects to your coax run coming from the coupler and the second is for feeding antennas that have a similar SO-239 connection point.
The tuner comes with a set of rails so that you can mount it to a post or board using a pair of U-Bolts. An option 12 volt AC adapter is also available.
So what’s different between the URT-1 and the MAT 40 tuner? Namely the addition of a 50 ohm coaxial output port and the removal of the brand specific control cables. The URT-1 is a bit more universal in that the coupler unit will work with just about any brand or model of transceiver.
How to use Use the URT-1
Using the URT-1 is pretty simple. We’ll first connect the coupler to our transceiver. My main antenna, a G5RV, is connected to my LDG auto tuner, so going to put this one onto the 2nd antenna port on my transceiver. A coax jumper goes from the radio to the coupler. The antenna coax is then connected to the other port on the coupler. Finally connect the power. The green power light should glow. If you see the red error light, that means the there is a short circuit somewhere in the coax connection between the coupler and the tuner.
When connecting the tuner, you can not have any devices like switches, diplexers, or meters in the path between the coupler and the tuner. These could cause a short circuit, potentially damaging the tuner or your device.
To initiate a tune, put your transceiver into a constant carrier mode like RTTY. Set the power level to 15 watts or less, briefly hit the tune button, and immediately key the transmitter. Watch the transceiver SWR meter and it will show the resulting SWR when the tuning cycle is complete. Unkey the transmitter. A complete tuning cycle will take five seconds or less.
At this point you can transmit normally. When changing bands, you will reinitiate the tune process. The tuner has 16,000 memories, so once the unit finds a good match, it will remember it for faster subsequent tunes.
Now let’s head outdoors and I’ll show you a couple of ways you can use the remote tuner in your portable amateur radio operations.
My experiences
What are my thoughts on the Chameleon URT-1 remote antenna tuner? First off, I must say that this unit is well constructed. The tuning unit consists of an aluminum alloy body that has a certain amount of heft to it. It wins points on that item alone. Taking this out into the field was a breeze as I didn’t have to run a separate control cable to the tuner for power. Operationally, it tunes fast and had no problem finding a match that was 1.5:1 or less. I think the only time I had issues with it getting a good match was with my 25 foot Franken-tenna on the 15 meter band. In that instance it gave up at about 1.8:1. But with the Frankentenna it did perform quite well on 10, 15, 20, and 40 meters despite the bands not being in the best condition. I made 210 contacts on those bands activating the Mountain Bay state trail, with the bulk of them on the 20 meter band.
With the end fed random wire antenna, I connected the tuner up to UHF connection on the antenna. The addition of the 9:1 transformer with the tuner made for super fast tune times. Every time it found a match at rocket speed. For that activation of Ackley Wildlife Area I ended up with 176 contacts on 10, 12, 15, 17, and 20 meters. The great thing about non resonant antennas is their agility. To switch bands, all I had to do was hit the tune button and I was good to go.
I had the same experience back here at home with the 71 foot non resonant wire. Once it learned the antenna, it would re-tune almost instantly. I was able to get matches with this wire from 10 meters all the way down to 80 meters. Operationally, the antenna performed just as well, maybe a bit better than with my other tuner located at the feed point. This antenna is being fed with 75 feet of RG-8X, so the better match at the feed point does make a difference.
As for things I don’t quite like about the tuner, First off these UHF ports are not labeled, so you need to look at the instructions to determine which goes to the coupler and which goes to the antenna. Also the ports didn’t come with covers. If you are using the bee hive connector, having a cover on the unused UHF port would be nice. I’ve got a friend that 3D printed some, so i did have something that worked. Finally, and probably the biggest, is that you have to press the tune button on the coupler to initiate a tune. If your SWR changes or you change bands, the tuner won’t automatically retune, it needs to be activated. That involves switching to a carrier mode like RTTTY, pressing the tune button, and then transmitting a carrier. Not the worst thing in the world, but also not fully automatic like some brands of remote tuners. But those require a separate control and power cable and up side of this tuner is that you don’t have to run a separate power and control cable to the tuner. Your power runs through the coax, which makes installation a breeze.
But, final words, I’ve been looking for a remote tuner at the hamfests. Everything I’ve seen is overpriced or in bad shape. It’s a bit serendipitous for Chameleon to be sending me this as it opens up the door to a bunch of different antenna configurations that I’ll be able to demonstrate. I’ve got some great ideas to use this tuner with, so you’ll want to stick around for that.
Build a random wire antenna and make amazing contacts: https://youtu.be/D_-aNzrIXWs
Yaesu FT-891 transceiver: https://amzn.to/3RSg4DO
213 inch whip antenna: https://amzn.to/3O3Bvkm
Feather Flag Base: https://amzn.to/3O6O7al
Antenna mirror mount jaw clamp: https://amzn.to/48yzRPL
3/8×24 SO-239 stud mount: https://amzn.to/3Sjre69
As a bonus, patrons can view the full, unedited phone contacts for this Parks on the Air activation. Visit my page on Patreon for details: https://www.patreon.com/kb9vbrantennas
I do return QSL, if you made a contact with me and would like a QSL, please send me one. Return postage not necessary, but always appreciated. As they say, KB9VBR is ‘good in the book.
Links may be affiliate links. As an Amazon Associate, I earn from qualifying purchases. This does not affect the price you pay.
Recent Comments