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Reviews Categories | Antenna Tuners | SGC SG-237 "Mini" Smartuner Help


Reviews Summary for SGC SG-237 "Mini" Smartuner
SGC SG-237 Reviews: 36 Average rating: 4.7/5 MSRP: $$339.99
Description: Antenna Coupler
Product is in production.
More info: http://www.sgcworld.com/products/sg237/
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You can write your own review of the SGC SG-237 "Mini" Smartuner.

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KA3RCS Rating: 5/5 Jan 5, 2014 03:11 Send this review to a friend
Superb autotuner  Time owned: more than 12 months
I spent years thinking about mobile HF antenna options, with just a Wilson 1000 and a 10 meter radio in the vehicle. Finally decided on the SG-237 to tune the same antenna, and paired it with an FT-857D.

I quickly realized that the matching coil in the Wilson antenna was fighting with the tuner and eliminated it, effectively ending up with a 5 foot whip connected directly to the tuner (which was mounted inside the roof of the vehicle, a few inches from the feedpoint). It would tune virtually anywhere from the top of 160 through 6 meters, though the radiation efficiency was obviously extremely poor on the lowest bands. It worked great on the higher bands.

I have since moved the radio and tuner to a different vehicle, though now feeding a different whip of similar length due to a completely different mounting configuration. It still works very well.

I had wired up a tune lock switch in the other vehicle, but have not yet done so in this installation. I really must do so, as the sporadic retuning events (even while stationary; possibly wind acting on the antenna or similar) can be annoying. I've seemed to the other station to disappear in the middle of a QSO several times. This is not the fault of the tuner, and is very simple to implement. I found that all I needed was a single SPDT center-off switch tying the control line either to +12 volts or ground, or leaving it floating in the center position. I'm planning to build a multifunction control box to accommodate this functionality (along with indicator LEDs), as well as a low power tune button for the radio (similar to the Quicksilver tuner box which worked so-so).

What I found to be quite convenient was to power the SG-237 from the tuner port on the FT-857. This way, the tuner automatically receives power whenever the radio is turned on. I've read comments about overloading that accessory power output causing damage, so I plan to add a tuner power fuse in the new interface box to protect the radio just in case.

In summary, the SG-237 is a rock-solid autotuner which just plain works, and works very well.
 
KF5GTX Rating: 5/5 Nov 2, 2013 21:51 Send this review to a friend
Fantastic tuner!  Time owned: more than 12 months
My elmer suggested purchasing this tuner for my Hustler 5BTV. Once we got it installed and operational, we tuned it on each band and found that it allows my Hustler 5BTV to operate on 160m, 30m, 12m and works very well.

I still need to build the control box for it so I can control it in the shack, but it is a GREAT tuner for the money in my QTH.
 
W3FLH Rating: 5/5 Oct 7, 2011 10:48 Send this review to a friend
Virtually "disappears" in my mobile  Time owned: more than 12 months
My experience pretty much echoes that of KK5JY in his first paragraph: I have mine mounted inside the tool box (plastic) in the bed of my truck, with #10 solid copper for the feedpoint and ground connections. It matches a 94" S/S whip easily on 40m and up with little or no problem; it'll match the whip on 80m (even 160m, FWIW), but the efficiency is so low, and since I only run barefoot, I don't venture down there that often.

KK5JY is right about paying close attention to SGC's instructions in terms of the power handling of the unit, but also about keeping the leads as short as possible. If you stick close to the installation guidelines, this little box really plays.

A little off-topic, but worth noting: I also use the AA4PB tune control between the '237 and an IC-706MKIIG, which becomes a seamless set-up in practice. With the tune cotrol in the LOCK position, the coupler doesn't want to re-tune due to temporary SWR changes. It also allows the rig's TUNE button to function as designed. One push of the button, and you're ready to go.

de Tony, W3FLH
73
 
VK3WHO Rating: 4/5 Mar 31, 2011 15:32 Send this review to a friend
very efficient mobile operation  Time owned: more than 12 months
I bought two of these units, one for us on my van and the other to setup at a friend place. The tuner works well on all frequencies from 7Mhz up on a 9 foot whip antenna although it sometimes refuse to auto tune. At 80 meters, the tuner isn't very efficient and can get quite warm when using an IC7000 for extended periods on SSB. I used this setup when traveling across Australia and it worked well. It allowed me to able to communicate back home on most night while being mobile over a distance of 2000 Km. It also relieved the monotony of traveling across central Australia where the roads are dead straight for 1000Km through the desert. As I mentioned before, my only complaint was that it some times locked up on 80, 40 and 30 meter where it wouldn't start to auto tune although the VSWR was bad enough to considerably reduce the power out of the IC7000. To work around this I moved the frequency past where you wanted to go so it would start to auto tuning and then bring it back..

To have the unit fixed in place in a home location on the roof was difficult to install, the main reason was to find a suitable earth.. This is pointed out several time in the documentation. The radio, a TS440 was located in the attic and would start operating erratically due to the large amount of RF not finding a suitable earthed point. It seems that this tuner suffered this problem a lot more than co-axial type antenna tuners that I have used in the past. I have tried using the tin roof in conjunction with the earth and decoupling the tuner from the radio with some improvement although it still isn't perfect.

The other problem with this tuner it will not tune with the power out of FT 817ND which makes a little disappointed as this is not a cheap tuner especially in Australia where they add extra 50% to the price . The FT817ND reduces power when a VSWR match is not found and the SG237 I found is only nominally rated at 3 Watt minimum input and usually required 5 Watts or more. I am now using a power supplied modified LDG IT-100 for this purposes and it works well.

In concluding, the tuner works well in mobile situation and seems to be very efficient on 7Mhz and above, is difficult to install if you can't find a very good earth in a home location and doesn't work with QRP radios.


 
KK5JY Rating: 5/5 Nov 15, 2010 22:18 Send this review to a friend
Extremely faithful.  Time owned: more than 12 months
I have one mounted in the bed of my truck for my mobile whip. It's not always fast, but it always finds a solution at 40m or better with my bed-mounted SS whip. It has done well with 80m solutions with slightly longer whips. I have used mobile whips from 6' through 30' without complaint. I did many contests mobile when I was apartment-bound. SSB, RTTY, CW, and this little tuner endured them all, in summer, winter, rain or shine.

I have also used this tuner with dipoles, although if you use a balanced antenna, choke the cable. SGC says that's not necessary, but I have had the experience of others with feedline radiation. Choked the feedline at the tuner and problem solved. Wrap its 9' cable on a toroid or use a prefab choke like you can get from DX Engineering.

Like it's big brother, the 230, this tuner needs a button or jumper of some kind that will allow you to force it to forget all of its memorized tuning solutions. This would make moving from one antenna type to anther easier if they have similar impedance characteristics. The "reset" on the SmartLock does NOT erase memories, it just sets the relays to "neutral." I have had less trouble with the 237 than with the 230 in this respect, so this tuner probably gets a 4.7. But it endured all my mobile use, and has matched (within reason) all my requests to tune unloaded whips, so I give it a 5.0.

I have also used it with an attic dipole and it tunes to 1.1:1 on all bands. Maybe I'm just lucky, but that's pretty awesome for a random-length (probably not even balanced) attic wire dipole.

Make sure you understand SGC's power limits for this unit when connecting to your 100W radio. I have not damaged one yet, but I have pushed it a little hard. If you want to go 100W RTTY in contests, you might want to think about going up to a 230 or 235.

A little pricey for a tuner that can only endure 40W continuous, but it is also perfect for my mobile application, mounted outside the cab of the vehicle. The entire base plate is the "ground" side of the antenna connection so it is easy to bond to a flat vehicle surface.
 
N6KZB Rating: 5/5 Sep 3, 2010 16:52 Send this review to a friend
SGC 237 & random wire  Time owned: 0 to 3 months
Needed to create a portable "all-band" antenna. Was willing to accept a compromise. The SGC-237 is feeding 55 foot of multi-strand #18 Ga. wire. The tuner is mounted on a second floor balconey. I use an additonal 25 foot of RG-8x coax and 2-stranded wire to extend the DC. The "end fed" wire runs towards the upper portion of the property and is tied off with an insulator to a 20 foot piece of top rail, tied to the property fence. The tuner and wire are about 30 feet off the ground. I use 3 counterpoise wires, above ground, each of differing lengths, and at differing angles. Longest 60 foot, mid size 35 foot, short one 18 foot. This seems to allow the tuner to find a match from 80-10 meters. I run an ICOM 7600 into it, and tune in AM mode when needed. The memories hang in pretty good to minimise re-tune solutions. It works. I did have an RFI issue on 30 meters, which I solved with a 30 meter counterpise wire from the radio ground lug, around the base board. Operating from a second story location is never ideal for grounding. I would recommend this "coupler", it is working as advertised.
 
N5VJA Rating: 5/5 Mar 8, 2010 21:14 Send this review to a friend
WOW! Perfect!  Time owned: more than 12 months
I have tried to find something this will not load up and failed! G5RVjr, Rain gutter, CB vertical antenna on 40 meters and still making euro contacts.

Worth every penny!
 
KK8ZZ Rating: 5/5 Nov 9, 2009 18:30 Send this review to a friend
Great with fixed Vertical  Time owned: 6 to 12 months
Works very well with a Zero-Five 43 foot antenna... you'll have to protect it from rain and snow, but other than that, it's a GREAT bargain used ! Just remember you need to supply 12v to it to let it operate... a little 4.5 amp 12 v battery in a Tupperware container and a 12V solar "trickle charger" was enough to keep mine operating 24/7/365 ... and you won't need the tune-lock thingy if you're using it at home... speedy tune !
 
N3NJ Rating: 5/5 Jun 15, 2009 18:12 Send this review to a friend
LOVE IT!  Time owned: 0 to 3 months
I have my smartuner mounted at the base of a 135' inverted L antenna and I can tune 160 thru 10 with no problems and I get great signal reports. I did take the time to install at least 8 ground radials in addition to an 8' ground rod. The unit is about 50' away from my house and shack. The vertical portion of the antenna is about 30' high. I am very pleased and I highly recommend this tuner. 73, Mark N3NJ.
 
K3ROJ Rating: 5/5 Mar 22, 2009 14:28 Send this review to a friend
Solved my antenna problems  Time owned: more than 12 months
Had used a Cushcraft R8 vertical for 5 years but wanted to experience 80 and 160 meters for a change. Asked HRO in Delaware what would be a good tuner to try with different antenna wires etc. Right away they mentioned the 237 and said it is their best seller for mobiles and fixed stations. Just experimenting with a total of 210 feet in a closed horizonal loop type antenna which fit in my back yard, it is amazing how many stations I can now work around the world. Since the tuner is located in a shed 60 feet from the house, I was able to have 12 volts for it and a good earth ground. It has worked without any problems now for over a year and stations on 160 meters are surprised I am only using medium power. One advantage of a closed loop is the lack of noise and can hear stations which others in my area cannot hear at all. Am now using the tuner and antenna with my new Flex Radio 5000A.
 
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