best antenna

[trigger]

I have a few questions I didn't see in reading the pages...
1. What's the cutoff for needing/not needing a amplifier on the coax? I have 25 feet to the USB.
2. Does it matter the type of coax/shielding on the 2 whips of the cantenna?
3. Do I need a crimping tool of some sort to make good coax ends or will just those screw on things work?
4. We know the soda can works, has anybody else tried a different size/material (coffee cans?)

Thanks in Advance! Can't wait to get testing!

Hi wxmeddler, welcome to the wire benders club!

abcd567 lives in an appartment so only gets a 180 degree view of the horizon. He will have some tips/tricks he will pass on I'm sure.

In answer to your questions
1) an amplifier will help in all circumstances if you have any sort of coax run between the antenna and the dongle. My range jumps about 80 nautical miles and the plane count almost doubles. I'm sure the noise is also amplified ...
2) abcd is the expert here
3) I terminate with F connectors. Anything which is outdoors needs to be wrapped in self amalgamating tape to keep out the weather
4) any sort of can will work. Obviously with aluminium you won't get corrosion. I've made ones from Red Bull, baked bean and a coffee can. They all work better than the provided antenna.

[abcd567]

i meant when they have been touched to move location etc. they end up being considerably different in their tuning.

I put it down to to the fact that relying on pressure from the cable it self to maintain a good connection is just unreliable, had better success with the push together ones when they were cable tied to a wooden rod.

Thanks for the clarification, I have misunderstood. Yes, you are right, mechanical forces in moving push-pin type coco may affect the joint. Your technique to tie the coco with a plastic, wood or bamboo stick using cable ties is a good solution.

[abcd567]

........
I have a few questions I didn't see in reading the pages...
1. What's the cutoff for needing/not needing a amplifier on the coax? I have 25 feet to the USB.
2. Does it matter the type of coax/shielding on the 2 whips of the cantenna?
3. Do I need a crimping tool of some sort to make good coax ends or will just those screw on things work?
4. We know the soda can works, has anybody else tried a different size/material (coffee cans?)

Thanks in Advance! Can't wait to get testing!

Hi wxmeddler, welcome to the wire benders club!

abcd567 lives in an appartment so only gets a 180 degree view of the horizon. He will have some tips/tricks he will pass on I'm sure.

In answer to your questions
1) an amplifier will help in all circumstances if you have any sort of coax run between the antenna and the dongle. My range jumps about 80 nautical miles and the plane count almost doubles. I'm sure the noise is also amplified ...
2) abcd is the expert here
3) I terminate with F connectors. Anything which is outdoors needs to be wrapped in self amalgamating tape to keep out the weather
4) any sort of can will work. Obviously with aluminium you won't get corrosion. I've made ones from Red Bull, baked bean and a coffee can. They all work better than the provided antenna.

trigger's reply is quiet accurate & comprehensive. Just to elaborate further:
(1) I use 50 ft RG6 between my antenna & DVB-T USB, and range with amplifier is 250 nm, which drops to 70nm when I remove the amplifier.
Amplifier has two-fold action:
(a) Since DIY antennas don't have the fantastic 6dB & 9dB gain (proclaimed by commercial antennas costing a fortune), using an amplifier helps to compensate the lower gain (2 dB to 6 dB) of DIY antennas, and will improve range even with short cable.
(b) It covers for cable loss if cable run is long.

(2) The type of insulation has negligible affect on the Cantenna whip as it is unshielded i.e. core wire & insulation only, no shield. You can use any type of insulation or better use a bare wire.
You have mentioned 2 whips. There is only 1 whip in Cantenna, not 2. I think it is a typing mistake, or do you mean Franklin Collinear which has 2 Limbs, up & down?

(3) You don't need a crimping tool if you use screw type F Connectors, which are readily available even in small stores. For outdoor use, purchase outdoor type screw F Connectors, or better use self amalgamating/self fusing tape wrap after installing the connector to protect from moisture & rain.

(4) Don't use less than 66mm dia (330ml/12oz Pepsi) can. Aluminum or steel does not make a difference, except aluminum is easier to cut & drill hole & does not corrode. I have used pepsi/coke can 66mm dia (330ml/12 oz) and a smaller size juice can 55mm dia (220ml), a larger hot chocolate 100mm dia cans & a copper water pipe 3/4" dia with pipe end cap. Range of 100mm dia & 66mm dia are almost same. Range of 55mmdia is slightly less than 66mm, and range of 3/4" (20mm) pipe is substantially lower than 66mm.

[abcd567]

Hi I have designed and built successfully an 8 element beam for ADSB. It has the same range as my 9 element wire collinear.
I have built 2 of these both with identical range - 270nm

[ATTACH=CONFIG]5184[/ATTACH]

The MMANA files are also attached

Mike
remove the .txt from this file before using in MMANA

Great! CONGRATULATIONS!
Gain=12.3 dBi, SWR (50 ohms)=1.2 Excellent!!!

YWYY_8EL1090mhz.PNG . YWYY_8EL1090mhz-2.PNG

[abcd567]

........
I have a few questions I didn't see in reading the pages...
......
2. Does it matter the type of coax/shielding on the 2 whips of the cantenna?
........

Please see detailed reply in above post #1965

For Cantenna's center, you can use any of the two connectors shown in in picture below. The left one is readily available at even small stores. The whip for both types of connectors can be with insulation (only wire+insulation, no shield) or bare conductor. Length of whip remains 69mm, irrespective of insulation type used, or if it is bare.

If you use barrel connector at left in the first picture below, the finished Cantenna will look like red Coke can (insulated wire) or Beans can (bare wire). Put a drop of hot melt glue where you insert the central whip to make it firm, else the whip may blow away with wind.

Make sure you don't use slim drink can. Use 2-5/8 inch (66 mm) dia can (355ml/12 fl. oz) or larger.

Please see photos below:
The beans can Cabtenna, (4th photo from left) is by planefinder forum member giacomo1989. (Scroll down the linked page as original photo & post is at almost bottom of the linked page)

Whip measurements-R.PNG . DSC03302-R3.jpg . 100mm dia cantenna.jpg . Beans can Cantenna-giacomo1989.jpg . DSC03299-R3.jpg

[wxmeddler]

Thank you all for taking the time to reply to my answers!

abcd, my bad on calling it two whips, I saw your small section of coax below the can and wrongly thought that was also called a whip. Thank you for the clarification.

The last thing I need on my list via the image posted on post #1920 is the power injector/ Wall transformer. I saw that User: Loplo provided a german amazon link on post #1946 however I cannot find anything comparable to it on American amazon. If possible, can someone link me to a good one? Also, now that I'm thinking about it, do we need a section of 69mm coax "inside" the can THEN the amplifier or just the amplifier in the can?

Thanks in advance.

[abcd567]

The last thing I need on my list via the image posted on post #1920 is the power injector/ Wall transformer. I saw that User: Loplo provided a german amazon link on post #1946 however I cannot find anything comparable to it on American amazon. If possible, can someone link me to a good one?

http://www.ebay.com/itm/Pico-Macom-P...-/221389012860

Pico Macom Power Inserter.JPG

OR



http://www.ebay.com/itm/HOLLAND-HR-P...-/271213268914

http://www.ebay.com/itm/Satellite-Li...-/111546368742

Power Inserter.jpg . Power Inserters.jpg

+

http://www.ebay.com/itm/18W-15V-1-2A...-/281472223135

http://www.ebay.com/itm/18W-15V-1-2A...-/261623993903

15V dc adapter usa.JPG

Also, now that I'm thinking about it, do we need a section of 69mm coax "inside" the can THEN the amplifier or just the amplifier in the can?

It can be both ways - amplifier inside the can, then coax, OR coax inside the can, then amplifier. It is your choice as it suites you.
The length of coax need not be 69mm. It can be any length as it suits you.
See the picture below where 3 Cantennas have 3 different lengths of coax. The can length & whip length in all 3 are 69mm.
DSC03299-R3.jpg

[YWYY]

YWYY:
I wanted to see in the format jpg.
Thank you in advance.

8element_adsb.JPG

As you wish
Mike

[abcd567]

@ wxmeddler :

You can use Cantenna without amplifier, but range will be limited without amplifier.

Amplifiers

RCA Amplifier.jpg http://www.ebay.com/itm/RCA-IN-SATEL...-/271708865557


$(KGrHqZHJFMFGw-VvzdiBRutzYSuLg~~60_12.JPG http://www.ebay.com/itm/SATELLITE-DI...-/380099079659

$_12.JPG http://www.ebay.com/itm/Philips-Digi...-/351194144428


m8MoEaIjghSTTVAONfDwwlg.jpg http://www.ebay.com/itm/IN-LINE-SATE...-/141043086029


amplifier china.JPG http://www.ebay.com/itm/New-Useful-S...-/201226765057

[HermanZA]

Hi I have designed and built successfully an 8 element beam for ADSB. It has the same range as my 9 element wire collinear.
I have built 2 of these both with identical range - 270nm

Well done on a successful built! What method did you use to connect your driven element to the feedline? I recall there is not a lot of space IN the tube to work.
270nM at what height ?

[abcd567]

Well done on a successful built! What method did you use to connect your driven element to the feedline? I recall there is not a lot of space IN the tube to work.
270nM at what height ?

Since YWYY has already done it, he is the best person to tell how to connect feed to driven element in such a small space inside the PVC boom. Just an idea came to my mind: cut two bays from a larger bank of terminal block, and use it to connect two limbs of driven element to core and shield of feed cable.

Terminal block.jpeg

[wxmeddler]

abcd567, Thank you for the links! My local hardware store actually had that same RCA amplifer, so I picked it up when I went to get the tape and connectors. I also found the power injector here for $15 USD plus shipping.

Unfortunately, I am going to have to leave the power injector until after the holidays since I'll be away from home and can't receive the package. Good news though is that I can compare the antenna with and without the power injector.

[abcd567]

abcd567, Thank you for the links! My local hardware store actually had that same RCA amplifer, so I picked it up when I went to get the tape and connectors. I also found the power injector here for $15 USD plus shipping.

Unfortunately, I am going to have to leave the power injector until after the holidays since I'll be away from home and can't receive the package. Good news though is that I can compare the antenna with and without the power injector.

If you don't have power inserter, don't install amplifier also.
An amplifier without power is an attenuator and reduces the signal.
You will be better off without amplifier, than with an amplifier and no power.

[YWYY]

Well done on a successful built! What method did you use to connect your driven element to the feedline? I recall there is not a lot of space IN the tube to work.
270nM at what height ?

Herman, once the 2 parts of the driven element are poked through the holes and meet inside the pipe, I bent the ends at right angle with a pair of needle nose pliers, solder the coax directly to the bent ends, that way the coax will lie straight along the pvc pipe. Cut the 2 driven element halves longer than needed at first, then once the coax is connected move both sections together as close as possible without touching. Then cut driven element to correct length. Once this is completed then the cut out in the pvc can be sealed with silicone. I forgot to add in my previous post , the copper wire elements are 2 mm, this is critical to performance.
I am at elevation of 160mtrs

DSC_0003[1].JPG

[abcd567]

........... My local hardware store actually had that same RCA amplifer, so I picked it up when I went to get the tape and connectors.........

If you have not discarded the packing of the RCA amplifier, please do me a favour and find the noise figure written on the packing. The amplifier's detailed specifications are given at front or back of the packing.

Unfortunately I have discarded the packing of my amplifier thinking the specs given on label of amplifier are sufficientpy detailed. Thank you.