Amplification warning

[themosttoys]

hi thermosttoys- just a quick question before I pull the trigger on the 8 dBi (LHCP) patch directional antenna you suggested http://www.l-com.com/wireless-antenna-2 ... h-antennas - you said this would probably out do the range of my tp link 14 dbi linearly polarized patch antenna http://www.amazon.com/TP-LINK-TL-ANT241 ... B003CFATOM because of being LHCP it would be properly matched to the LHCP of the p2v camera/vtx's antennas- just confirming you still think this is true because even though the tp link is mis matched (linear to circular)- you said the drop would be 3dbi- so effectively it would still be 11DBi- that's still 3dbi more than the 8dbi (LHCP) patch directional antenna- could you share briefly why you think the LHCP patch will likely still out do the higher gain linear patch providing more video range? thank you

It's what I call a guestimate.
First consideration is that the -3dbi is a guarantee under optimal conditions and could be greater. Or another way to look at it is that the circ pol patch should be more forgiving than the linear.
Second is the lobe difference between 8dbi and 11dbi is realistically outside our human ability to aim (unless very lucky). For example, in my testing of the 14dbi TPLink and a much smaller 12dbi L-Com patch antenna, I saw comparable results (actually doing a little better with the 12dbi L-Com over the 14dbi TPLink.) But again, I was aiming myself so human error needs to be considered.
Last thought is that the results PVFlyer is seeing with his setup (using LHCP helicals) is very surprising to me. He has not changed the tiny side firing directional antennas on the P2V and supposedly has flown past 2km without having to turn the P2V (to aim one of the directional antennas back at him). If this is to be believed (and I have no reason to not believe him) then the only reason could be because of the antenna match. No matter what I did, with any linear antenna(s) configuration and any amount of MIMO repeater amplification, I could not come close to his results (until I changed the antenna on the P2V).

At the end of the day, as always, your mileage may vary. Good luck.

 

[theSelf]

hi thermosttoys- just a quick question before I pull the trigger on the 8 dBi (LHCP) patch directional antenna you suggested http://www.l-com.com/wireless-antenna-2 ... h-antennas - you said this would probably out do the range of my tp link 14 dbi linearly polarized patch antenna http://www.amazon.com/TP-LINK-TL-ANT241 ... B003CFATOM because of being LHCP it would be properly matched to the LHCP of the p2v camera/vtx's antennas- just confirming you still think this is true because even though the tp link is mis matched (linear to circular)- you said the drop would be 3dbi- so effectively it would still be 11DBi- that's still 3dbi more than the 8dbi (LHCP) patch directional antenna- could you share briefly why you think the LHCP patch will likely still out do the higher gain linear patch providing more video range? thank you

It's what I call a guestimate.
First consideration is that the -3dbi is a guarantee under optimal conditions and could be greater. Or another way to look at it is that the circ pol patch should be more forgiving than the linear.
Second is the lobe difference between 8dbi and 11dbi is realistically outside our human ability to aim (unless very lucky). For example, in my testing of the 14dbi TPLink and a much smaller 12dbi L-Com patch antenna, I saw comparable results (actually doing a little better with the 12dbi L-Com over the 14dbi TPLink.) But again, I was aiming myself so human error needs to be considered.
Last thought is that the results PVFlyer is seeing with his setup (using LHCP helicals) is very surprising to me. He has not changed the tiny side firing directional antennas on the P2V and supposedly has flown past 2km without having to turn the P2V (to aim one of the directional antennas back at him). If this is to be believed (and I have no reason to not believe him) then the only reason could be because of the antenna match. No matter what I did, with any linear antenna(s) configuration and any amount of MIMO repeater amplification, I could not come close to his results (until I changed the antenna on the P2V).

At the end of the day, as always, your mileage may vary. Good luck.

thanks again for your awesome input! ps- is this the 12dbi L-Com patch antenna you speak of and if so is it linearly polarized as opposed to CP? http://www.flyteccomputers.com/details. ... wb=HG2412P

 

[themosttoys]

thanks again for your awesome input! ps- is this the 12dbi L-Com patch antenna you speak of and if so is it linearly polarized as opposed to CP? http://www.flyteccomputers.com/details. ... wb=HG2412P

You are welcome. Yes it is the antenna and yes it is linear.

 

[theSelf]

thanks again for your awesome input! ps- is this the 12dbi L-Com patch antenna you speak of and if so is it linearly polarized as opposed to CP? http://www.flyteccomputers.com/details. ... wb=HG2412P

You are welcome. Yes it is the antenna and yes it is linear.

actually- I just found this-

Found these LHCP helical antennas- http://www.antennaexperts.in/model-detail.asp?RecID=60

http://www.antennaexperts.in/product-de ... enna&id=17

don't know how reliable this company is - but if we could get a LHCP helical like this on the repeater only, will save having to add an antenna to the p2v camera/vtx, for optimal range..(since of course the stock p2v camera/vtx antennas are LHCP and because of the lack of LHCP antennas out there and an abundance of RHCP, to keep the match in direction of polarization when getting a helical antenna and only coming normally in RHCP, p2v camera/vtx antennas have needed to be changed to RHCP, but this may help avoid having to do that- I'd prefer not to have to add an antenna to the p2v as well because of added weight, drag, time to install and cost)

anyone think this LHCP helical could be effective?

 

[themosttoys]

actually- I just found this-

Found these LHCP helical antennas- http://www.antennaexperts.in/model-detail.asp?RecID=60

http://www.antennaexperts.in/product-de ... enna&id=17

don't know how reliable this company is - but if we could get a LHCP helical like this on the repeater only, will save having to add an antenna to the p2v camera/vtx, for optimal range..(since of course the stock p2v camera/vtx antennas are LHCP and because of the lack of LHCP antennas out there and an abundance of RHCP, to keep the match in direction of polarization when getting a helical antenna and only coming normally in RHCP, p2v camera/vtx antennas have needed to be changed to RHCP, but this may help avoid having to do that- I'd prefer not to have to add an antenna to the p2v as well because of added weight, drag, time to install and cost)

anyone think this LHCP helical could be effective?

Based on PVFlyer's testing, this should work. It would be great to have someone else test LHCP to see if the same results can be achieved.

 

[themosttoys]

Have not had any time to fly, but stayed up late and ditched the 1000mah battery saving 60g. Still need to test both (to see what the trade off is between 60g of weight vs pulling power from the main battery.) I'm happy with how it came out (notice the JST plug in the bottom of the P2V.) I debated using heavier wire (so that I could mount an extra battery) but it was late and I just wanted to get it done.

 

[theSelf]

Have not had any time to fly, but stayed up late and ditched the 1000mah battery saving 60g. Still need to test both (to see what the trade off is between 60g of weight vs pulling power from the main battery.) I'm happy with how it came out (notice the JST plug in the bottom of the P2V.) I debated using heavier wire (so that I could mount an extra battery) but it was late and I just wanted to get it done.

very cool- how do you land/take off with the antenna below the skids? Do you only take off/land to your hand? You may find these longer landing legs useful if you need some extra height to land on the ground- https://www.facebook.com/media/set/?set ... 991&type=1

 

[themosttoys]

very cool- how do you land/take off with the antenna below the skids? Do you only take off/land to your hand? You may find these longer landing legs useful if you need some extra height to land on the ground- https://www.facebook.com/media/set/?set ... 991&type=1

For power on and take off I rotate the antenna so that the P2V sits flat on the ground. After takeoff I rotate the antenna to point straight down (by hand). To land I just catch, any emergency landing could damage the antenna and / or cause the P2V to tip (perhaps damaging two props.) I have some ideas on how to do this better, just need time to fabricate something.

 

[theSelf]

[

Based on PVFlyer's testing, this should work. It would be great to have someone else test LHCP to see if the same results can be achieved.

there's also these two high gain LHCP helical antennas:

Blackhawk 2.4 GHz Helical (LHCP) Heavy duty version
http://horizonfpvantennas.mybigcommerce ... y-version/

and


2.4 GHz Helical (LHCP) short lightweight version
http://horizonfpvantennas.mybigcommerce ... t-version/

good if you are in the UK- but fairly pricey to ship abroad otherwise, yet do look perfect for the job..

anyone wanting to experiment and report back?

 

[oukenfold]

[

Based on PVFlyer's testing, this should work. It would be great to have someone else test LHCP to see if the same results can be achieved.

there's also these two high gain LHCP helical antennas:

Blackhawk 2.4 GHz Helical (LHCP) Heavy duty version
http://horizonfpvantennas.mybigcommerce ... y-version/

and


2.4 GHz Helical (LHCP) short lightweight version
http://horizonfpvantennas.mybigcommerce ... t-version/

good if you are in the UK- but fairly pricey to ship abroad otherwise, yet do look perfect for the job..

anyone wanting to experiment and report back?

i just order one of this yesterday 12db, now i have to wait from uk to mexico ****, the other side of the world. hope ship fast.

 

[oukenfold]

very cool- how do you land/take off with the antenna below the skids? Do you only take off/land to your hand? You may find these longer landing legs useful if you need some extra height to land on the ground- https://www.facebook.com/media/set/?set ... 991&type=1

For power on and take off I rotate the antenna so that the P2V sits flat on the ground. After takeoff I rotate the antenna to point straight down (by hand). To land I just catch, any emergency landing could damage the antenna and / or cause the P2V to tip (perhaps damaging two props.) I have some ideas on how to do this better, just need time to fabricate something.

what antenna are u using in the pv2 camara, i see your are only using one right? i dont have ans amplifier, i guees you have really more range with that setup, by the way how can you know the antennas on the vision are LHCP?

 

[themosttoys]

very cool- how do you land/take off with the antenna below the skids? Do you only take off/land to your hand? You may find these longer landing legs useful if you need some extra height to land on the ground- https://www.facebook.com/media/set/?set ... 991&type=1

For power on and take off I rotate the antenna so that the P2V sits flat on the ground. After takeoff I rotate the antenna to point straight down (by hand). To land I just catch, any emergency landing could damage the antenna and / or cause the P2V to tip (perhaps damaging two props.) I have some ideas on how to do this better, just need time to fabricate something.

what antenna are u using in the pv2 camara, i see your are only using one right? i dont have ans amplifier, i guees you have really more range with that setup, by the way how can you know the antennas on the vision are LHCP?

The antenna on the P2V is a Circular Wireless SPW24.
Correct, I'm only using one.
I've not had a chance to test the ultimate range (probably beyond the flight time). The real point of the amplifier is not so much ultimate range but penetration. I don't want to think about orientation or if I'm flying behind a tree.
I know the antennas on the P2V are circular polarized by looking at them. I only know that they are LHCP because of the testing done by PVFlyer. It is possible (although not likely) that they are LHCP & RHCP.

 

[theSelf]

[

Based on PVFlyer's testing, this should work. It would be great to have someone else test LHCP to see if the same results can be achieved.

there's also these two high gain LHCP helical antennas:

Blackhawk 2.4 GHz Helical (LHCP) Heavy duty version
http://horizonfpvantennas.mybigcommerce ... y-version/

and


2.4 GHz Helical (LHCP) short lightweight version
http://horizonfpvantennas.mybigcommerce ... t-version/

good if you are in the UK- but fairly pricey to ship abroad otherwise, yet do look perfect for the job..

anyone wanting to experiment and report back?

i just order one of this yesterday 12db, now i have to wait from uk to mexico ****, the other side of the world. hope ship fast.

excellent! the shorter or heavy duty one? Keep us posted regarding your results

 

[theSelf]

actually- I just found this-

Found these LHCP helical antennas- http://www.antennaexperts.in/model-detail.asp?RecID=60

http://www.antennaexperts.in/product-de ... enna&id=17

don't know how reliable this company is - but if we could get a LHCP helical like this on the repeater only, will save having to add an antenna to the p2v camera/vtx, for optimal range..(since of course the stock p2v camera/vtx antennas are LHCP and because of the lack of LHCP antennas out there and an abundance of RHCP, to keep the match in direction of polarization when getting a helical antenna and only coming normally in RHCP, p2v camera/vtx antennas have needed to be changed to RHCP, but this may help avoid having to do that- I'd prefer not to have to add an antenna to the p2v as well because of added weight, drag, time to install and cost)

anyone think this LHCP helical could be effective?

Wow- got a quote back from this company and this is what they wrote-

Our price quote for 2.4GHz LHCP helical antenna is US$450 each.
Minimum order quantity is 2 units.
Estimated FedEx shipping cost for 2 units is US$150


that's ridiculous- a 'no go' for me

the other 'horizonfpvantennas.com ones look much more promising and affordable

Blackhawk 2.4 GHz Helical (LHCP) Heavy duty version
http://horizonfpvantennas.mybigcommerce ... y-version/

and

2.4 GHz Helical (LHCP) short lightweight version
http://horizonfpvantennas.mybigcommerce ... t-version/


though shipping to the US is fairly pricey

 

[theSelf]

[

Based on PVFlyer's testing, this should work. It would be great to have someone else test LHCP to see if the same results can be achieved.

there's also these two high gain LHCP helical antennas:

Blackhawk 2.4 GHz Helical (LHCP) Heavy duty version
http://horizonfpvantennas.mybigcommerce ... y-version/

and


2.4 GHz Helical (LHCP) short lightweight version
http://horizonfpvantennas.mybigcommerce ... t-version/

good if you are in the UK- but fairly pricey to ship abroad otherwise, yet do look perfect for the job..

anyone wanting to experiment and report back?

here's the email response on the antenna specs from horizonfpvantennas-

here are some dimension details

The BH+ Long heavy duty sizes


Width of reflector 9cm
Length of antenna 27cm
width of boom 4.5 cm
weight with pole clamp 280 grams or 9.7 oz


The BH+ Short heavy duty sizes

Width of reflector 9cm
Length of antenna 14cm
width of boom 4.5 cm
weight with pole clamp 230 grams or 7.7 oz



Nimrod 2.4 GHz sizes
width at base 8cm
width at top 4.5 cm
height 4 cm
weight 34 grams OR 1.2 oz


With you application, if the quad is using LHCP the BH+ H/duty long or short would work fine but a doubt if the antenna built into the camera transmitter is up to the mark.
A proper LHCP CP antenna would be better to give better results.


Ranges , well we have tests our set at over 11 km for RC control, It all depends on the power from the VTX as you know.


obviously adding an antenna to the p2v would help but I'm trying to avoid that and this seems to be best long range option without having to add anything to the p2v..

 

[PVFlyer]

The antenna on the P2V is a Circular Wireless SPW24.
Correct, I'm only using one.
I've not had a chance to test the ultimate range (probably beyond the flight time). The real point of the amplifier is not so much ultimate range but penetration. I don't want to think about orientation or if I'm flying behind a tree.
I know the antennas on the P2V are circular polarized by looking at them. I only know that they are LHCP because of the testing done by PVFlyer. It is possible (although not likely) that they are LHCP & RHCP.

Per the pictures taken by themosttoys, both antennas are with the same part# and same way of truncated corner & feed line, I believe they both are LHCP.

 

[theSelf]

The antenna on the P2V is a Circular Wireless SPW24.
Correct, I'm only using one.
I've not had a chance to test the ultimate range (probably beyond the flight time). The real point of the amplifier is not so much ultimate range but penetration. I don't want to think about orientation or if I'm flying behind a tree.
I know the antennas on the P2V are circular polarized by looking at them. I only know that they are LHCP because of the testing done by PVFlyer. It is possible (although not likely) that they are LHCP & RHCP.

Per the pictures taken by themosttoys, both antennas are with the same part# and same way of truncated corner & feed line, I believe they both are LHCP.

no -thermostoyys can confirm but I'm certain they are both RHCP- as most cp antennas available are only rhcp so if getting one helical that is rhcp you need to get a rhcp antenna also for the p2v to match the polarization direction but if the repeater has a lhcp helical on it not as much need to have a skew planar or cloverleaf on the p2v but if you did the skew planar world have to be lhcp as well...getting a lhcp helical only for repeater for me in theory would be a good option if you don't want to add an antenna to the p2v

 

[theSelf]

The antenna on the P2V is a Circular Wireless SPW24.
Correct, I'm only using one.
I've not had a chance to test the ultimate range (probably beyond the flight time). The real point of the amplifier is not so much ultimate range but penetration. I don't want to think about orientation or if I'm flying behind a tree.
I know the antennas on the P2V are circular polarized by looking at them. I only know that they are LHCP because of the testing done by PVFlyer. It is possible (although not likely) that they are LHCP & RHCP.

Per the pictures taken by themosttoys, both antennas are with the same part# and same way of truncated corner & feed line, I believe they both are LHCP.

you referring to the stock p2v camera antennas or thermostoyys' new antennas on the repeater and p2v?-thermostoyys can confirm but I'm certain the replacement ones are both RHCP- as most cp antennas available are only rhcp so if getting one helical that is rhcp you need to get a rhcp antenna also for the p2v to match the polarization direction but if the repeater has a lhcp helical on it not as much need to have a skew planar or cloverleaf on the p2v but if you did the skew planar would have to be lhcp as well...getting a lhcp helical only for repeater for me in theory would be a good option if you don't want to add an antenna to the p2v

 

[themosttoys]

you referring to the stock p2v camera antennas or thermostoyys' new antennas on the repeater and p2v? PVFlyer is referring to the stock antennas. -thermostoyys can confirm but I'm certain the replacement ones are both RHCP- True, the antennas I'm using are RHCPas most cp antennas available are only rhcp so if getting one helical that is rhcp you need to get a rhcp antenna also for the p2v to match the polarization direction but if the repeater has a lhcp helical on it not as much need to have a skew planar or cloverleaf on the p2v but if you did the skew planar would have to be lhcp as well...getting a lhcp helical only for repeater for me in theory would be a good option if you don't want to add an antenna to the p2v This is what PVFlyer has done, he made two LHCP helicals only he has attached them to a separate repeater / amp, but you could attach them to the stock repeater just fine.

 

[oukenfold]

guys in the moorning i buy 2 antenas from horizonfpvantennas, yes they are price buy look excelent quality, they write me this:

Hello Jorge,

Yes the order is in hand , yours is a special as it's LHCP, so its a custom build for you .

You antenna will be upgraded to Gold plated elements as we have just introduced this new spec.
We noticed however that you have not ordered any SP antenna to math with it like this one .

http://horizonfpvantennas.mybigcommerce ... igid-rhcp/
Since this order is going to Mexico it may be worthwhile adding a SP antenna to match up also LHCP

but with LHCP , you need to select the Gold elements option if you need them, other wise they will be
the double wound versions.

Shipping after the Build would be in the beginning on the week.he store will keep you posted on the prograss

Thanks

William
HFPV

----------------------------------

Hello again Jorge, yes i can sort out a LHCP SP for you in silverplated semi tigid coax ,

with spring steel/ Copper elements , or you can have silver plated or GOLd Plated to match up to the Helical BH+
you have ordered, also if you need a strait on 90 deg connector on this one,

We can ship it all together but i thing the shipping would be more than the store added of only £8.50 to Mexico !!

so best thing to do is I build it for you and pack it all up then get the shipping costs and tell you the difference to send over

It is best to match up a SP with your antenna as there would be nothing to work with it otherwise, using RHCP with is would give a -100 dB missmatch which you do not want, is there a reason you went for LHCP ? , we can change it all the RHCP if you like.

Best
William
HFPV

so i buy 2 antennas,

1.- http://horizonfpvantennas.mybigcommerce.com/2-4-ghz-sp-antenna-semi-rigid-lhcp/
2.- http://horizonfpvantennas.mybigcommerce.com/blackhawk-2-4-ghz-helical-lhcp-long-heavy-duty-version/

if this do not work a give up! sell my vision :?