Nick | Jan. 20, 2024

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Josh | Dec. 2, 2020

Mike | Aug. 2, 2020

Udo | June 1, 2020

The antenna is fine , but shipping is a long wait...

For 300MHz+ Log Spiral Antenna with Suction Mounts

The antenna arrived 7 weeks after ordering , without any shipping details or tracking options.
I mesured the antenna with my R&S ZVL 18 networkanalyser and the plot in the advert is correct. Meaning that the antenna is usable from 380MHz upto 6GHz.
Below 380MHz the returnloss is not good enough ( SWR way too high) to be usable in a transmit application.

Response from Hex and Flex | June 2, 2020

Hi Udo,

Apologies for the slow delivery. International fully tracked delivery is very expensive as I do not sell enough to get a good trade discount. Using such services would significantly increase the price I would have to charge. Normally shipping arrives within the quoted 10 days, but on occasion there are unforseen delays which are normally associated with local postal services or customs clearances. All items are correctly marked to ensure the most expeditious clearance. I do think COVID19 has caused many delays worldwide recently, but I have been unable to get specific details from Royal Mail on a country by country basis.

Regarding performance, I am sorry that the antenna SWR does not meet your requirements for transmit. Such requirements are generally specific to the output amplifier of your system and I am not able to give a universal answer on its suitability for each and every system. For the majority of lower power systems the result is limited to a reduction in overall efficiency. Your spiral antenna has better than 50% efficiency at 300MHz. Again depending upon the specifics of your application this may or may not be considered good. For example a mobile phone maker would be pretty pleased with 50% efficiency within the size constraints of the device, a radar designer would not.

I do try to be as open and honest about the performance of my antennas as possible and try to provide as much reliable performance data as possible to enable those with specific requirements to make informed descisions. As you state, the antennas do meet the published specifications. However as these antennas did not meet your expectations, I would be happy to provide a refund? Just let me know in the comment below, or contact my Tindie store link.

Wish you all the best with your project.
HeexAndFlex

Joel | June 1, 2020

P J | May 21, 2020

John | May 2, 2020

Erich | Nov. 26, 2019

Franky | May 9, 2019

amazing ...

For Ultra-WideBand Vivaldi Antenna 800MHz to 6GHz+

When I saw this thing I thought, yea right, a piece of pcb with a pattern of a palm tree leaf on it, what nonsense are they trying to sell me this time. Then, for no peticular reason, when I read the designer 's documentation, I started to get curious. I think this gentleman had put a lot of effort and energy into explaining and documenting his antenna design, and this together with the publication of test results from an independent company specialized in RF measurements of antennas, I just had to continue to investigate this.
After a bit of duckduckgo'ing (google'ing for people who love privacy .... they say) this turned out to be a no nonsense antenna, on the contrary this was one where there is a fair amount of fuss about , because of the return size/ performance appears to be large.
When I also saw the more than reasonable price that was being asked, I had wasted more than 5 times the money on other so-called pcb antennas, I thought, ok, I want to know the bottom things about this, and I ordered one.
To make a long story shorter now, the first thing I did when I had this thing in my hands 2 days after ordering,
was connecting it to my cheap cinese spectrum analyzer in combination with a likewise cheap VSWR bridge, it can only measure up to 1.5GHz, this is a fraction of the bandwidth of the vivali palm leaf antenna, I know , but better than nothing , right??.
Well this was a very pleasant surprise, it turns out that what I can measure is entirely consistent with what is being told by the designer, not that I did not believe this gentleman but it is in my nature to check things as much as I can for myself . This has completely reassured me that this is "the real thing" and not "fake news" :-)
This vivaldi palm leaf antenna, 2 of them, one vertikally and one horizontal polarized mounted, are now in use on my Huawei B525 4G + internet modem.
Signal level of this went from -90dBm to -70dBm, signal-noise went from 10dB to 15dB and as a result of this the download speed went up
from 30-50Mb / sec to 100Mb / sec, and sometimes even more than that.
All this thanks to 2 Vivaldi antennas aimed at the nearby 4G + mast (+ - 400m).
Well I know there will be people who read this, who will think "Bullshit", well in that case I like bullshit, no fake news here people, I am telling you exactly what I am experiencing.
My complements to the designer, this is a job more than well done, amazing.
Regards,

Waterschoot Franky.

(forgive me for my maybe funny name sounding, but I am from Belgium .... now that's what i call a excuse, not?) :-P

Response from Hex and Flex | May 11, 2019

Hi Franky, thanks for your amazing review. So pleased you like them. I totally dig your initial scepticism. I did spend a lot of time on the design and simulation and owe a massive debt of thanks to AntennaTestLab for the final measurements.
It's also really great to hear your experiences with 4G. Thats a great solution for those with slow internet and on the edge of 4G coverage.

Dave | Feb. 17, 2019

Emmanuel | Feb. 6, 2019

Yashin | Jan. 2, 2019

P.M. - Antonio J. | Sept. 21, 2018

Rik | May 6, 2018

good antenna,

For Ultra-WideBand Vivaldi Antenna 800MHz to 6GHz+

This is about the duo set, with the spacing units:
too many ways to mount the wrong way..
the pictures on the website are not so clear

Response from Hex and Flex | May 6, 2018

Hi Rik,

Sorry if it was confusing. Have you managed to assemble it yet? If not then please reach out to me via the contact seller link and I will try and help.

I did add a number of spare threaded holes for the M2.5 and Tripod mount. This was in case someone managed to strip a thread, but I can see how it might be confusing.

I also added some vertical threaded holes. You can use these to mount the antenna at 90degrees or to screw the brackets flat to the antenna for storage so as to keep everything together.

I will try and write up a short guide to show a couple of ways it can be assembled.

Lawrence | April 18, 2018

Really a professional looking job

For Ultra-WideBand Vivaldi Antenna 800MHz to 6GHz+

I don't have equipment to check the performance of this board, but that has already been done. I've never seen a board with such thick coatings and with the data printed on the coating. There will be no question of what this is in the future. I did put it on the various SDR boxes I have around that cover those frequencies and it picks up more signals than I can identify. N0UU

Response from Hex and Flex | April 18, 2018

Glad your happy with it. I am a big fan of parts with the basic specs printed or engraved on them so once I had the reliable measurements from AntennaTestLab I had to do it. I used to use old HP directional couplers with the full S parameter charts printed on them, Really handy. I hate having to look on the internet for an obscure part number every time especially if there is no manufacturer name or they went out of business.

Richard | April 6, 2018

very nice indeed

For Ultra-WideBand Vivaldi Antenna 800MHz to 6GHz+

Ordered the dual antenna with holder kit.

Nice design and well documented with professional measurements to boot!
Arrived promptly and well packed.
Very responsive seller. Thanks for the help and support.

The dual antenna holder is also well thought through and allows for an easy installation of the antennae at 90 degrees and the mounting of a coaxial relay to switch between polarisation remotely.

Will do an Rx Tx trial shortly and find a good way to weatherproof the whole assembly now.

Response from Hex and Flex | April 7, 2018

Many thanks for the review.

The extra holes were added to enable the antennas and brackets to be stored flat together without loosing bits. I had never thought about using the brackets to mount them at a right-angle, great idea.

Everyone who buys an antenna pair from this point should be getting this new improved version.

Aurelien | Feb. 20, 2018

Juan J. | Jan. 15, 2018