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Reviews Categories | Antennas: VHF/UHF+ Omnidirectional: verticals, mobile, etc | STI-CO Flexi-whip Help

Reviews Summary for STI-CO Flexi-whip
STI-CO Flexi-whip Reviews: 3 Average rating: 5.0/5 MSRP: $40.00
Description: 1/4 wave NMO style mobile antennas that use a unique, flexible whip that will bend but not break or remain bent. Great for use in areas with low garages or trees that would otherwise destroy other traditional "rod" antennas.
Product is in production.
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WA4SSG Rating: 5/5 Jun 14, 2016 20:31 Send this review to a friend
Indestructible  Time owned: 3 to 6 months
I bought a new SUV and at the same time, my parking garage at work changed to a place with just about 8 inches of roof clearance for the new car. I looked at all sorts of roof mounted antennas, including models with springs, but I was concerned that hitting the overhead pipes could put too much stress on the NMO mount that might damage the roof of the car. I had heard that the Virginia State Police uses the STI-CO whip on all of their police cars with excellent results. I read the two reviews on this site and decided to try one. I purchased the whip from Tessco.

I really needed a VHF-UHF antenna because my Icom 5100 is a dual band radio. I used a Comet antenna analyzer to find the sweet spot in the 2 meter band while also checking SWR and impedence in the 440 MHz band as well. By trimming the whip to about 19.5 inches, I found the SWR below 1.5 to 1 at 50 ohms impedence on VHF and even lower on UHF while maintaining 50 ohm impedence. While this is not designed or marketed as a dual band antenna, it works as expected for a quarter wave whip on 2 meters with essentially equal performance on 446 MHz.

I have been very pleased with the performance and don't worry about the whip hitting anything. It bends easily, but remains vertical at highway speeds. When I no longer have the low clearance garage to deal with, I will probably replace it with a dual band antenna made for the ham bands, like a Comet SS 460 SB NMO which I have used with good results and which has some gain on UHF, but for now the STI-CO is working great and it allowed me to install a roof antenna that covers two bands and still get the car into places with little overhead clearance.

By the way, the bandwidth on this is amazing. The cutting chart shows an SWR at 146 MHz below 2:1 over 24 MHz, or 12 MHz either side of the resonant frequency. At UHF frequencies it is below 2:1 over 90 MHz.

Be careful not to damage the tool you use when cutting the whip. While the antenna is very flexible, the material is hard as a rock.

The black finish and small diameter of the whip makes it very unobtrusive. This is a great product that most hams don't even know about because it is aimed at the commercial market.
N1WT Rating: 5/5 Dec 8, 2009 11:47 Send this review to a friend
Virtually Indestructable  Time owned: more than 12 months
I have been using these for a few years in both amateur and commercial service. I have them installed on well over a hundred school buses which eat up normal 1/4 wave antennas as well as fire, police and EMS vehicles. I have not had single one go bad and they are abused on a regular basis. If you destroy one of these you should closely examine how you treat your equipment.
KK7AC Rating: 5/5 Jun 15, 2004 21:31 Send this review to a friend
An "alternative" antenna  Time owned: 3 to 6 months
I wanted to install NMO roof mounted antennas for my new GMC Yukon for APRS (1/4 wave 2 meter) and a 1/2 wave for my UHF mono band. My delima was that my garage elevation at the door header is 7 ft. Even being a 2 wheel drive truck, roof mounted, even 1/4 wave VHF and 1/2 wave UHF, would bind up and eventually bend and weaken over time while going in and out of the garage. What to do?

I recalled seeing an antenna manufacturer in one of my trade magazines, MRT, that advertised an antenna that was tied in a knot like a pretzel. I knew that this product was geared toward my problem so I went into the back issues to retrieve information. I say this because STI seems to be only advertizing to the LMR / Public Safety crowd, and not, at this time, showing their interesting products to amateurs (ie- QST, CQ).

Discription- this particular antenna is a "typical" NMO based antenna that arrives like most 1/4 wave antennas; 21 inches in lenght, NMO style mount, and 17 ft. of attached coax. All you do is attach to a 3/4 hole or mag mount (if you opt for that option) and cut to frequency per supplied cutting chart. However, this is not your typical NMO run-of-the-mill 1/4 wave Larsen or Antenna Specialist (not that these forementioned antennas are poor, their different) antenna. This is made of a rubber-duck like round round wire that can be turned into a pretzel, but springs right back to position without fatige (ie- bent). They are attrative in appearnce-(they are black and look great on my black GMC Yukon with black tinted windows --looks like a presidential motorpool) and have a rubberized "heatshrink" tubing type covering that protects the "wire" element. But they are still just as thin as a traditional rod spun element.

I am very happy with these antennas so far. I'm using a 1/4 wave on 2 meters and using an Antenex base with a STI whip for my 1/2 wave 440 MHz antenna. The only "disadvantage" at this time is that you buy the entire system. In otherwords, you cant just buy the whip to cut and stick in your favorite 1/2 wave base or trusty Larsen NMO... You have to shell out for the base, whip and cable assembly.

I hope that they will provide only the whips for replacements in the future and begin catering to the amateur community. It is a great choice for those who have "overhead" issues like mine. Go to the website to see them in action....they are very inovative.

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