I might give it a go, any suggestions on if this is classed as a 1/2, 1/4 or full dipole for the length of radials?
Never had a chance to see it physically, only seen in this photo.
Assesing from photo, it looks from top to bottom:
1/2 or 5/8 radiator, coil, 1/4 radiator, 1/4 decoupling sleeve.
I’ve tried to replicate it, based on the image (not magnified).
here are some issues.
- this is an approximation based on overall advertised length of about 64cm.
- the antenna is certainly calibrated
- the bronze (?) elements and in these dimensions hard to get.
- inside the rings maybe additional components (coils ?) exist
the antenna performs very poorly compared to cantenna and spider !!!
the cantenna with the top element (coil) only, trimmed to 1/2 and 1/4 wave performs
much better than the single wire.
FYI
2 Likes
Can not make out what you mean. A sketch or photo will help.
1 Like
sure, here it is. hope is clear ? 13.8 cm top, coil 4 turns φ=1 cm, bottom 6.9 cm.
1 Like
Yes it is clear now. Thanks
Frequency Sweep (From 100 MHz to 2500 MHz) of Wire Collinear Antenna and 1/4 Wavelength Ground Plane Antenna.
The frequency sweep results of a high gain wire collinear antenna show that it not only performs best at its designed frequency, but also performs fairly good at or near sub-multiples and multiple frequencies.
This characteristic of collinears is good for multi-band reception such as single antenna used by Armature Radio Hobbyists for 2 meter band and 6 meter bands. However it has disadvantage for single frequency reception that the RF signals picked from all these multiple & sub-multiple bands necessitates a tuner circuit or a filter at front end (i.e. between antenna and receiver).
The frequency sweep results of a 1/4 wavelength ground plane antenna show that it gives good performance at and near its designed frequency only, and at other far away frequencies its performance is poor. Hence the 1/4 wavelength ground plane antenna picks very little harmonic and sub-harmonic frequency signals.
WIRE COLLINEAR ANTENNA WITH DECOUPLING SLEEVE
Click on the thumbnails to see full size images
. 
. 
. 
1/4 WAVELENGTH GROUND PLANE ANTENNA (Cantenna)
Click on the thumbnails to see full size images
. 
. 
. 
2 Likes
I have ordered this one, waiting for delivery.
It is Canadian $4.8 (US $3.64) + Free Shipping.
Worth trying. Even if it proves rubbish, not a big loss. I will still have 2 pigtails for CA$4.80 
I will use these pigtails to connect FA Filter to the 2 Generic DVB-T (black) dongles I have.
1 Like
I have two of them (supposedly the 1090 ones). One doesn’t work at all, one works as good as cantena, but only if the bottom part is straight. Bending that reduces the performance.
1 Like
@SoNic67
Thanks for feedback.
When I ordered these a week ago, I had in mind that when I will try them, most likely both will prove rubbish. No problem, their cost is that of a small burger, or that of a cup of coffee at Starbucks 
2 Likes
Actually I have a plan for one of them, I’m just too lazy going for it.
I think it would be worth while to re-examine the can-tenna
This is the results of my homebrewed cantenna but I get hits over 300 miles out in certain directions I dont see this on my FA Black antenna.
What is the dia and height of can you used to make your Cantenna? May be you have hit an optimum design by using this particular can.
Is the whip 1/4 wl (69mm) or different?
1 Like
The element is number 30 drill stem cut to 69 mm or actually 2.67 inches I used my calipers to measure the length. Can size is a standard can of corn from walmart. Seriously.
I’m going to have to play with some more cans. My first cantenna ( coke-tenna) was blah.
I’m running un-amplified other than a blue FA Pro+ stick.
1/4 wave spiders run well for me.
Not sure I have optimized the FA antenna yet, I think more height would greatly aid reception on it.
My mystery collinear is the best I have, I want to rip it apart to find out what I did that makes it work so well as the next three I made from the same piece of coax were mediocre at best. 
1 Like
1 Like
Bought one, will await its arrival and comparison to the Spider and FA Ant.
1 Like
15.25 ounce can. I may climb up there later on to look closer.
1 Like
I climbed up on my roof and this is what I have. Its the 29 ounce can and the element is the 69MM made from the center conductor of RG8 cable. The one I described before is in my shed since its all rusted up. I measured the element length using my set of calipers at 2.67 inches which is 69mm. This one I used a SO239 feed through and shoved the conductor into the center pin and hot glued it into place. The feed through is fastened to the can.
1 Like
This is the best part, experimenting and see what our out come is. 1090 mad scientists!
1 Like