I have some of these from Wilson that are used for 4G LTE. They don't have a lot of gain and are not very directional but the wide bandwidth is needed for cellular signals that range from 600-2500 Mhz. One problem I've had is the white plastic case only lasts about a year in the Arizona sun before falling apart then has to be replace with a new box. There is a similar model from China on Ebay for half the price that is a knock off of the Wilson and while the antenna itself works well it comes with a length of junk RG8 cable that has very high loss so I cut it off at just 4 feet and installed a new connector to make the antenna usable.
extend the centre feedline (the "split boom") by a cm or two and add another smaller pair elements at the front in the same fashion and it should cover up to 2700Mhz. Rather than extend the boom parts themselves, you may be able to just bolt extend the boom with some aluminium strips - ensure a couple of CM overlap. Aluminium oxide doesn;t conduct (not very well anyways) BUT with sufficient overlap it doesdn;t need a direct electrical connection (at DC) because at RF (we're talking 700MHz+ after all) the overlap will have sufficient capacitance to couple through any oxide layer (the oxide layer forms on all aluminium in seconds after cutting/sanding/filing - you can't really avoid it - but like I say at high UHF you need nt worry about it, just ensure enough overlap to reduce losses)
Also, one of the ARRL Antenna Books has a great article about log periodics, including design charts for maximum gain, spacing, number of elements etc. Think it may be the purple-cover one from the 80s? - not sure if later editions one have it. AIUI, more elements in a given boom length gives slower VSWR, as any 3 elements at any given frequency are in action. The rest act as less influential reflectors and directors, and the more they are "too long" and "too short" spectively, the less efficient they are at giving gain. Longer booms give more gain, for a given amount of elements, up to a certain limit, then it tails off. As usual in ARRL books, lots of charts and nomograms so not too hard on the maths. The L-Ps I've built in years gone by were more "by eye" than calculation, and worked just fine, even up towards 3GHz. My rule was "if in doubt, just make all elements long then trim them off with a ruler for a nice slope at top and bottom" haha. I make a few with 12 SWG solid copper for the boom and 14SWG for the elements at high UHF. Then just snip to length. The split-boom spacing (and dimensions) do affect characteristic impedance so if you use different boom materials experiment with the spacing - it acts like a feedline.
I too picked up a couple of cheap LPDA antennas in a similar case to what you have here in the video, for $14 USD. They have twice the amount of elements on them (30 in total) doubles of each length on opposing dipoles. The sticker on the back says a 9-10 DBI gain, which I believe is higher than this. I haven't installed them yet, but am likely going to use them polarized (90°). Going on my cell signal booster.
i just got wacked £100 for two log periodic with 5m sma leads, is thet good or should i get a refund or partial refund? i think that's taking the piss when i see people getting them 8 dollars.
I'm interested in a PCB version of this, specifically whether a dual polarised version could be constructed (2 of them co-located and mounted at 90 degrees to each other). Then whether you could use a cheap satellite dish as a reflector mounting the antenna in the reverse direction as a feed horn. Would make a great project ;)
Once again, thanks for a interesting video. One question about Polarisation, would it work better if I use two (2) antennas, one horizontal and one vertical? Second question about mounting, can I mount it indoors or does it have to stay outdoors. Indoors I could use much shorter coaxial cables. A tip to those who do not get a better signal. This is an Directional Antenna not an Omni-Directional Antenna. You’ll need to align your directional antenna with the nearest signal mast. It gives the maximum amount of gain from one direction, so useful when you have marginal signal.
I would also be interested to know whether two antennas will work better than one and the orientation of these. How much signal can be expected to be lost when using an ebay type extension cable with connector instead of making a custom soldered SMA coax cable?
Another interesting video, Im working my way through all your previous ones. Thank you. Could a biquad antenna be made with a rectangular shape instead of a square - such that it could be a multiband antenna?
I did the same a year or so ago - bought a 4G LTE and it marginally helped. - That's why I sent this request to Andy >> (note the build quality on my purchased unit was rubbish,... I had to strip it down and rebuild it & add new/decent 50ohm coax. @AndrewMcNeill - Great find,... and result for the price. Can't wait to see your take on improving the design/manufacture and build it along with you. - - Any chance of posting the ORIGINAL eBay ITEM number (seller) so I may get one to do a similar PLAY/MAKE/BRAKE ??? . .
Hi @andrew mcneil. FYI, I have clicked on a few of your vids eBay links and they are broken. Just letting you know. If you read this, can you reply with your general store details? Thanks!
I've been using the similar antenna about years ago. Some strange reason I've outcoming LTE traffic bigger, then incoming. First time see it in mobile internet (O2 LTE Uk provider). Does it telling, what use a wrong polarisation, my antenna in vertical, like in this video, please?
I doubt it achieves full 10 to 12 dBi as advertised. Branded LDPAs in the £60 price range, e.g. Wittenberg LAT 58 with somewhat longer booms (1 m) and a lot more elements (58) only achieve 9 to 11 dBi. The number of elements in LPDAs and Yagis correlates with the gain factor to my knowledge.
Same. He was probably being lucky with some clearance or B stock? Still some 20-30% cheaper than branded ones made in the EU, but possibly lower gain in practice.
Nahh. There is back bleed from log periodic antennas though the return signal hitting the antenna blasts back and down from the antenna a little bit though from image ive seen its not much but still significant. Its not just point to point like you think.
@AndrewMcNeill - Great find,... and result for the price. Can't wait to see your take on improving the design/manufacture and build it along with you. - - Any chance of posting the ORIGINAL eBay ITEM number (seller) so I may get one to do a similar PLAY/MAKE/BRAKE ??? . .
@@andrewmcneil I guess my slight critique of your video, then, is that you referred to the price about half a dozen times with emphasis and come to find out, the source is no longer available for that price. Small hit. Otherwise, awesome presentation! I have two of these left over from a work project... Always wondered how good they were. Cracked one of mine open also. Log Periodics are ALIEN compared to a Yagi that I have come to understand! 😜 Appreciate you!
Interesting. There are two main versions of this, one is a bit shorter and cheaper with a slighly lower gain and is quoted as between 800-2700MHz and the longer one between 600-2700MHz. I wonder if some of the shorter ones are mounted in the larger box by some suppliers?
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I am also amazed at the value here.
Thank you for your hard work.
I love seeing the analysis of these antennas
Glad you enjoy it!
WOW,... this is the first time i found someone tear down this antenna on internet ,, Thanks, LIKE it, ^^
I'm glad you like it
Great video and interesting antenna, that was quite a wide response.
It reminds me of the giant log periodic antennas, that you see in EMC labs.
I have some of these from Wilson that are used for 4G LTE. They don't have a lot of gain and are not very directional but the wide bandwidth is needed for cellular signals that range from 600-2500 Mhz. One problem I've had is the white plastic case only lasts about a year in the Arizona sun before falling apart then has to be replace with a new box. There is a similar model from China on Ebay for half the price that is a knock off of the Wilson and while the antenna itself works well it comes with a length of junk RG8 cable that has very high loss so I cut it off at just 4 feet and installed a new connector to make the antenna usable.
I have yet to find an original antenna from China LOL
i hope you can do some LTE mimo and parabolic antenna nextime btw thanks for this great videos
extend the centre feedline (the "split boom") by a cm or two and add another smaller pair elements at the front in the same fashion and it should cover up to 2700Mhz.
Rather than extend the boom parts themselves, you may be able to just bolt extend the boom with some aluminium strips - ensure a couple of CM overlap. Aluminium oxide doesn;t conduct (not very well anyways) BUT with sufficient overlap it doesdn;t need a direct electrical connection (at DC) because at RF (we're talking 700MHz+ after all) the overlap will have sufficient capacitance to couple through any oxide layer
(the oxide layer forms on all aluminium in seconds after cutting/sanding/filing - you can't really avoid it - but like I say at high UHF you need nt worry about it, just ensure enough overlap to reduce losses)
Also, one of the ARRL Antenna Books has a great article about log periodics, including design charts for maximum gain, spacing, number of elements etc. Think it may be the purple-cover one from the 80s? - not sure if later editions one have it.
AIUI, more elements in a given boom length gives slower VSWR, as any 3 elements at any given frequency are in action. The rest act as less influential reflectors and directors, and the more they are "too long" and "too short" spectively, the less efficient they are at giving gain.
Longer booms give more gain, for a given amount of elements, up to a certain limit, then it tails off.
As usual in ARRL books, lots of charts and nomograms so not too hard on the maths.
The L-Ps I've built in years gone by were more "by eye" than calculation, and worked just fine, even up towards 3GHz. My rule was "if in doubt, just make all elements long then trim them off with a ruler for a nice slope at top and bottom" haha. I make a few with 12 SWG solid copper for the boom and 14SWG for the elements at high UHF. Then just snip to length.
The split-boom spacing (and dimensions) do affect characteristic impedance so if you use different boom materials experiment with the spacing - it acts like a feedline.
I too picked up a couple of cheap LPDA antennas in a similar case to what you have here in the video, for $14 USD. They have twice the amount of elements on them (30 in total) doubles of each length on opposing dipoles. The sticker on the back says a 9-10 DBI gain, which I believe is higher than this. I haven't installed them yet, but am likely going to use them polarized (90°). Going on my cell signal booster.
i just got wacked £100 for two log periodic with 5m sma leads, is thet good or should i get a refund or partial refund? i think that's taking the piss when i see people getting them 8 dollars.
I'm interested in a PCB version of this, specifically whether a dual polarised version could be constructed (2 of them co-located and mounted at 90 degrees to each other). Then whether you could use a cheap satellite dish as a reflector mounting the antenna in the reverse direction as a feed horn. Would make a great project ;)
You haven't shown the spacing between the top and bottom elements, you only need to show one as all the rest can be worked out.
Once again, thanks for a interesting video.
One question about Polarisation, would it work better if I use two (2) antennas, one horizontal and one vertical?
Second question about mounting, can I mount it indoors or does it have to stay outdoors.
Indoors I could use much shorter coaxial cables.
A tip to those who do not get a better signal.
This is an Directional Antenna not an Omni-Directional Antenna.
You’ll need to align your directional antenna with the nearest signal mast.
It gives the maximum amount of gain from one direction, so useful when you have marginal signal.
I would also be interested to know whether two antennas will work better than one and the orientation of these. How much signal can be expected to be lost when using an ebay type extension cable with connector instead of making a custom soldered SMA coax cable?
Another interesting video, Im working my way through all your previous ones. Thank you. Could a biquad antenna be made with a rectangular shape instead of a square - such that it could be a multiband antenna?
Possibly!
I just bought an antenna like this one, perhaps it is the same one, but sadly, it's not improving my cellular reception.
I did the same a year or so ago - bought a 4G LTE and it marginally helped. - That's why I sent this request to Andy >> (note the build quality on my purchased unit was rubbish,... I had to strip it down and rebuild it & add new/decent 50ohm coax.
@AndrewMcNeill - Great find,... and result for the price. Can't wait to see your take on improving the design/manufacture and build it along with you.
- - Any chance of posting the ORIGINAL eBay ITEM number (seller) so I may get one to do a similar PLAY/MAKE/BRAKE ???
.
.
Hi @andrew mcneil. FYI, I have clicked on a few of your vids eBay links and they are broken. Just letting you know. If you read this, can you reply with your general store details? Thanks!
I've been using the similar antenna about years ago. Some strange reason I've outcoming LTE traffic bigger, then incoming. First time see it in mobile internet (O2 LTE Uk provider). Does it telling, what use a wrong polarisation, my antenna in vertical, like in this video, please?
Waiting for the parabolic LTE antenna. Love you
Very soon!
@@andrewmcneil Thank you very much :)
@@andrewmcneil Waiting impatiently for that one too!
I doubt it achieves full 10 to 12 dBi as advertised. Branded LDPAs in the £60 price range, e.g. Wittenberg LAT 58 with somewhat longer booms (1 m) and a lot more elements (58) only achieve 9 to 11 dBi. The number of elements in LPDAs and Yagis correlates with the gain factor to my knowledge.
accordingly to the chanpuak online calculator, something 30 cm long can gain more than 7.3 dbi. Something 1 meter long 9.8 dbi
LPDA or MIMO Which is best for 4g network , from 4km cell Tour.......?
Parabolic
I have a Chinese version but it doesn't have impedance cap would that affects frequency or dbi gain
Also please make a video to make at home for personal use
They're not showing up on eBay for £8.50 only about 30 do u have a link
Same. He was probably being lucky with some clearance or B stock? Still some 20-30% cheaper than branded ones made in the EU, but possibly lower gain in practice.
Great video. Thanks
What about getting a second one and using using it with a HUAWEI B331 Homehub on the Three Network.
I was thinking the same, just add satelite dish of 90 cm as reflector and use it with Huawei B535
Is it cut dipole in to half off full length in logpariodic antenna?
Could you try the same S11 measurement without the plastic case?
Yes but any difference would be small
Is there a link to this product?
Better than biquad?
impressive frequency range, but what is this aerial actually for? External aerial for mobile phone?
Probably for items like 4G hotspot or cell booster.
@@SimonShaws thanks
where can I get a pair of these plz?
yessssssss goood
ive got 2 of these in the loft right above my bed where i sleep. should i be worried about radiation?
Are you worried about radiation from your cell phone? Do you have your head at the pointy end of the antenna?
Nahh. There is back bleed from log periodic antennas though the return signal hitting the antenna blasts back and down from the antenna a little bit though from image ive seen its not much but still significant.
Its not just point to point like you think.
Poderia ser feito com fio 2.5 de cobre
Thank you!
You're welcome!
Can anyone mention the real gain of this antenna?
Have 2 of them, they dont work at all. router works better without it. same inside. Tried every orientation
Does your router normally have internal antennas? If so you need to select external antennas from the settings menu. Which router were you using?
can you test 4g modem patch antenna
@AndrewMcNeill - Great find,... and result for the price. Can't wait to see your take on improving the design/manufacture and build it along with you.
- - Any chance of posting the ORIGINAL eBay ITEM number (seller) so I may get one to do a similar PLAY/MAKE/BRAKE ???
.
.
I did not link it because he did not have any left tinyurl.com/y3x7dmqh
@@andrewmcneil - Big thanks Andrew.
@@stevemacbr No problem Steve
@@andrewmcneil I guess my slight critique of your video, then, is that you referred to the price about half a dozen times with emphasis and come to find out, the source is no longer available for that price.
Small hit.
Otherwise, awesome presentation! I have two of these left over from a work project... Always wondered how good they were. Cracked one of mine open also.
Log Periodics are ALIEN compared to a Yagi that I have come to understand! 😜
Appreciate you!
If you can't find them on ebay then you're not looking, mostly Chinese sourced so broaden your search outside Europe.
Very interesting.
Please show you elemen
how to wire connect ??? help plz...
The Ali Express one is better, I got the Ali one first then the eBay one, the Ali one fills the housing.
Interesting. There are two main versions of this, one is a bit shorter and cheaper with a slighly lower gain and is quoted as between 800-2700MHz and the longer one between 600-2700MHz. I wonder if some of the shorter ones are mounted in the larger box by some suppliers?
Can you please share a link? thank you!
اريد القياسات من فضلكم
will this work in Australia Telstra 3&4 G????
Yes, especially Band 28. Telstra 4GX is 700-800MHz roughly. 3G is about 850MHz.
- Yeah,... just check frequencies against the sweep Andy showed.,.... the -50db notch is the gain and response envelope.
Yesss
Anybody with a link for purchase
tinyurl.com/y3x7dmqh but is out of stock
РазмерыLPDAWiFi
i hope you can do some LTE mimo and parabolic antenna nextime btw thanks for this great videos
I second that!!!