SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Oct 25, 2010, 09:02 PM
Questionable judgement
bracky72's Avatar
Charles Town, WV
Joined Jan 2008
3,072 Posts
I have never tried building one of your antennas before but I think I will try this one for 2510 mhz. Thanks.
bracky72 is offline Find More Posts by bracky72
Reply With Quote
Sign up now
to remove ads between posts
Old Oct 25, 2010, 09:50 PM
'FPV'er...not a "LOS'er
Vantasstic's Avatar
Las Vegas, NV
Joined Sep 2003
18,376 Posts
I take it the bowtie being horizontal provide the correct polarity for a vertical VTx antenna?
Vantasstic is offline Find More Posts by Vantasstic
RCG Plus Member
Old Oct 25, 2010, 10:29 PM
Flying with the eagles
etman's Avatar
Eagle's nest
Joined Nov 2008
2,121 Posts
Wonderful! Subscribed.
etman is offline Find More Posts by etman
Reply With Quote
Old Oct 25, 2010, 10:33 PM
Cape Cod
tom3holer's Avatar
Cape Cod
Joined Sep 2010
905 Posts
IBC,

Once again you have come up with that seems to be almost too good to be true.

One question if I may slightly off the subject. I am also on 900mhz and was wondering if you have done the "SAW" mod to your receivers and was it worth it. I have the new Saw filters already. I thought I read somewhere you did it and did not think it was worth the effort.

Tom
tom3holer is offline Find More Posts by tom3holer
Reply With Quote
Old Oct 25, 2010, 11:24 PM
Registered User
Australia, QLD, Gold Coast
Joined Aug 2007
856 Posts
Alex, you must be a teacher, you are so patience to explain every thing and you do it well.
Thanks
I made mine PCB base and I'm using it for a while, This antenna works just fine.
http://www.rcgroups.com/forums/showthread.php?t=1301126
Now Im planning to make a new one and use PCB for antenna element instead of wire, I mean to print the antenna element on a piece PCB, It would be neat.
Talajouy is offline Find More Posts by Talajouy
Reply With Quote
Old Oct 26, 2010, 04:25 AM
Registered User
Portugal
Joined Nov 2009
791 Posts
All the dimensions remain the same using the pcb, galvanized steel or other material?
HF_ATL is offline Find More Posts by HF_ATL
Reply With Quote
Old Oct 26, 2010, 04:56 AM
Honey Badger
Blue Chip's Avatar
United States, FL
Joined Oct 2005
1,814 Posts
If using a tracker - is there any reason to have more than one of these? Seems like this on a tracker and a di-pole for close in would do the trick.
Blue Chip is offline Find More Posts by Blue Chip
Reply With Quote
Old Oct 26, 2010, 06:04 AM
Engineer for Christ
IBCrazy's Avatar
Amherst, VA
Joined Jun 2006
10,453 Posts
Vantasstic - Yes, the bowtie should be flat, not upright. Look at Talajouy's.

Talajouy - I wrote the tutorial because the Martybugs tutorial wasn't that easy to follow or build. Your BiQuad is a work of art! My next one will be with a steel wire.

HF ATL - Any metal will work. Dimensions remain the same.

Blue Chip - This is a great antenna to use with a tracker.
IBCrazy is offline Find More Posts by IBCrazy
Reply With Quote
Old Oct 26, 2010, 07:05 AM
Registered User
Norway, Hordaland, Bergen
Joined Feb 2009
280 Posts
Hi IBC,

I see you run the coax trough the reflector and fold back the screen and then connect it to the reflector.
On many other bi-quads I have seen that they connect the screen when it goes trough the reflector.
Have you done any simulations (or reading) on which method is best, or if it is the same?

Megafluffy
Megafluffy is offline Find More Posts by Megafluffy
Reply With Quote
Old Oct 26, 2010, 07:46 AM
Engineer for Christ
IBCrazy's Avatar
Amherst, VA
Joined Jun 2006
10,453 Posts
Quote:
Originally Posted by Megafluffy View Post
Hi IBC,

I see you run the coax trough the reflector and fold back the screen and then connect it to the reflector.
On many other bi-quads I have seen that they connect the screen when it goes trough the reflector.
Have you done any simulations (or reading) on which method is best, or if it is the same?

Megafluffy
Actually, it doesn't matter much, but will make some difference. So long as the shield remains around the center conductor up to the connection point with the bowtie, it really makes little difference. However, you need to keep the shield from fraying. I suggest that if you use this method you solder all the way around the edge of the shield to keep it from fraying.

I simply ran my simulations based on my design.

On the other hand, many use a small copper tube to feed the coaxial line through. I did not do this simply to cut down on the amount of material needed. I made my design as easy to do as possible with minimal parts count. Future builds will be of a more rugged design. This unit was built for this tutorial and testing.

-Alex
IBCrazy is offline Find More Posts by IBCrazy
Reply With Quote
Old Oct 26, 2010, 02:37 PM
Sink? Circling now to confirm.
JONBOYLEMON's Avatar
United States, UT, American Fork
Joined May 2002
17,046 Posts
This looks like a doable build for me. Thanks in advance for all your work!!!!!!!!!!
JONBOYLEMON is offline Find More Posts by JONBOYLEMON
Reply With Quote
Old Oct 26, 2010, 06:52 PM
Registered User
Italy
Joined Jun 2010
97 Posts
HI IBC,
already did myself a patch and many dipole following your instructions (and they are good!), now it's time for the biquad.

Is 10 AWG Iron wire any good for the bowtie?
What diameter is just righ with iron?

A piece of wood glued on the back is ok for mounting on the tripod/ tracker?
jhoexp is online now Find More Posts by jhoexp
Reply With Quote
Old Oct 26, 2010, 09:18 PM
Engineer for Christ
IBCrazy's Avatar
Amherst, VA
Joined Jun 2006
10,453 Posts
10 AWG is a bit excessive for anything over 900MHz. For 900 MHz, 10 AWG is fine.

You can use anything on the backside of the reflector to mount it so long as it is an insulator. And even then, it's not that critical.

-Alex
IBCrazy is offline Find More Posts by IBCrazy
Reply With Quote
Old Oct 27, 2010, 11:42 AM
Registered User
techspy's Avatar
USA, NC, Matthews
Joined Aug 2008
3,243 Posts
I will be building this one soon. Couple questions... Does painting (light spray paint) have any discernible effect on performance? I am thinking flat black but would there be any benefit to a chrome/copper type paint?

Thanks
techspy is offline Find More Posts by techspy
RCG Plus Member
Latest blog entry: My Esprit Saga
Reply With Quote
Old Oct 27, 2010, 01:13 PM
Engineer for Christ
IBCrazy's Avatar
Amherst, VA
Joined Jun 2006
10,453 Posts
Quote:
Originally Posted by techspy View Post
I will be building this one soon. Couple questions... Does painting (light spray paint) have any discernible effect on performance? I am thinking flat black but would there be any benefit to a chrome/copper type paint?

Thanks
None what so ever
IBCrazy is offline Find More Posts by IBCrazy
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Build Log How To Build a BiQuad RX antenna Talajouy FPV Talk 21 Dec 22, 2010 11:52 PM
Question DIY Biquad antenna for a 900mHz Moosthegoose FPV Talk 5 Jan 14, 2010 03:37 AM
Discussion Antenna tutorial JIMOOO FPV Talk 1 Feb 25, 2007 12:04 AM
Discussion looking for a DIY tutorial. TonyBAMF Beginner Training Area (Aircraft-Electric) 8 Jan 10, 2006 04:56 PM
I need help to DIY flywire antenna for 36 MHZ RX GoodHeli Radios 5 Aug 24, 2003 08:05 PM