Sorry abcd567, had I known it was your drawing I would have given you credit. I found the image in Google image search.
…Tom
Hi Tom
This can happen. It is ok. No need to be sorry.
ab cd
What are youre impressions with the different TOP parts??
How do they compare??
I haven’t been able to connect my filter as of yet as the ends are SMA and I have a F-Type Coaxial so adapters should be here soon so that I can hook this in line as well.
Word of advice, connectors connectors connectors. I didn’t pay much attention to them when ordering but it certainly has eaten 2 weeks of time up getting everything connected.
Results:
Control: Chrome telescoping antenna that came with the Dongle. I was getting 200 mile range and roughly 850 ish on the planes per day. I had this attached to the back of my DirecTv dish as it’s a magnetic base.
Next I put the amp and the CoCo (coaxial antenna) up and the results were about the same as the control so I gave it a day and went to the next antenna. Range has not really changed. Largely not impressed with this one.
Canantenna: SUPRISE this kicked the control and the CoCo’s ass. Plane and simple anyone can make this and it works GREAT, planes jumped to over 1000 so about 20% jump. Range is picking up 200-250 but very few. Mounted to a 3’ PVC tube atop the roof about 25’ ABGL
Next: Spider. I took a connector and made cut a square piece of tin out and put four wires, one on each corner, on it pointing downward at 45 degrees. This has produced about a 10% increase and it looks like today’s results will be the largest yet. Range is 200-250, not a lot, but the most so far. Mounted to a 3’ PVC tube atop the roof about 25’ ABGL
I’ve tried to compare days of the week to like days of the week as a control as well.
System:
Pi, running the Flightaware software only
NooElec NESDR Mini 2 USB
Have a MX cable to F adapter to a short piece of Coaxial plugging into the Power inserter.
“DIRECTV PI21R1-03 Power
Have about 24” of Coaxial cable between the power inserter and the AMP
Perfect Vision PVAMP1 Satellite Signal In-line Amplifier Booster 20 dB 950-2150 MHz LNB Dish TV Video DSS DBS Digital Antenna Coaxial Cable Run Channel Strength, 13 - 18 VDC, Part # Perfect PVAMP1 (AMSIA2)
VBFZ-1065-S+ BANDPASS FLTR / SMA / RoHS EA (yet to be installed waiting for the adapters to connect this to the F cable.)
Antenna.
I have all this just sitting in the open on the top of my roof. Nothing to protect nor interfere with it as of yet. I figure it’s not going to rain anytime soon in California so this was just an easy thing to do and I wanted to keep the coaxial lengths as short as possible.
I don’t know how to attach a picture on this site so I cannot show the stat’s page for you guys at this time.
Amazon Prime has been my savior there a few times. I’ve pretty much always been able to find what I need and have them delivered in two days for free. 
My 8-element CoCo has smoked any other antenna I’ve ever built. Granted, I’m now using the third one that I’ve built and made sure to take my time with this one, find the exact velocity factor of the cable, cut each element to the exact length based on the velocity factor, added a 1/4 whip to the top, etc… I was so happy with this one that it now lives in a PVC pipe on the roof and works like a champ.
Just to confirm… You’re placing the amp as close as possible to the antenna and the VBFZ-1065-S+ filter close to the Pi / SDR, yes?
The amp needs to be close to the antenna to boost the RF signal prior to it taking a journey through the coax, where the RF signal will drop off. If you place the amp on the far end (away from the antenna), you’re amplifying whatever is left after the journey all the way from the antenna, which will be a much lower signal (depending on the length of your feed line) than what you had coming straight out of the antenna. You’ll also be amplifying whatever noise was picked-up in the coax feed line. The one downside to the Perfect Vision amps is their ~6dB of insertion loss, which makes keeping them as close as possible to the base of the antenna even more important.
The VBFZ-1065-S+ should be the last thing in the chain prior to your SDR. While I love that filter and have several of them, they also have a bit of insertion loss. Installing the filter between the antenna and the amp will immediately kill some of the aircraft that were barely hitting your antenna anyway, which means they won’t be there for amplification by your amp and will never be seen by the SDR.
Ideally, the setup should look something like this:
SDR → short MCX-SMA adapter cable → VBFZ-1065-S+ filter → SMA-F adapter → coax → power inserter → coax feed line to antenna → amp → DC-blocker (optional but recommended) → antenna
Store the picture on Dropbox / Google Drive / Flickr and paste the public share link here.
Matt
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8 elements homemade Coco in the attic +preamp/saw. Doubled the positions number since I put the preamp in the circuit 
Did 320 NM with a plane north of Manchester a few days ago.
Currently I have…
Pi with the dongle plugged into it and this feeds upwards to the power inserter and then this via a short coaxial cable feeds to the amp which is directly attached to the center adapter with the 69mm copper wire on it, with witch the threaded portion sandwiches a metal plate with the additional four spider legs.
I had originally a small 2.5" OAL length of coaxial cable to connect the AMP to the Spider but I ordered some female to female F connectors from “Showmecables” which are about 1/2" OAL so I just put one in this morning to shorten the distances even more. It took like 30 minutes for the up-link to get back on line after I insterted that??
Was going to put:
Spider Antenna
FILTER
AMP
Coaxial cable
Power Inserter
Short MDX cable
Dongle
Pi
I though it would be smart to filter out the bad and then amp the good down to the Dongle but your saying to put the filter between the Dongle and the Power insterter closest to the Dongle and then filter out anything after it has been amplified?
What the H, I’ll try it as it’s not hard to do.
Do not have a DC Blocker, don’t know if I need one or?
Have considered adding a duplexer, but don’t know if I need one either.
I had the best count yesterday of 1,208 planes and this is roughly speaking a 50% increase over the chrome telescoping anteanna. Now I’m mounting these antennas directly next to a DirectTV dish so if I put these on the opposite end of the house maybe it would make a difference, I just don’t know how far the wireless can transmit. It’s only another 50’? so if I can get it to connect after I get this thing dialed in I will be curious to see if it matters and also I will have to probably at some point increase the length of the coaxial cable between the power insterter and the amp in order to get the things out of the elements but being in CA, I’ve got till December to worry about rain.
Thanks!
How do you know the exact velocity factor and such? I just made my CoCo like the ones I’ve seen in here and in video’s. 108mm of jacketed RG6 Coaxial cable with about 18mm of wire exposed on each end with a piece of electrical tape between the two ends.
Put it in a PVC pipe as well as it made mounting easy.
I’ll reply to this in greater detail later this evening when I’m not on my phone.
I will go ahead and mention that a diplexer isn’t necessary as the Mini-Circuits filter you’ve got will filter things down to a tighter range of frequencies than a diplexer and do a better job of it. Because you were willing to spend the $40 on that filter, a diplexer isn’t needed.
Yes, the filter needs to be the last thing in line prior to the dongle. As I explained earlier, adding it between the antenna and the amp will only drop the power going in to the amp even lower due to the insertion loss of the filter. It’s not much, but it’s enough to kill the signal coming in from aircraft that you were barely hearing from in the first place.
Can you post some pics of your setup so we can get a better idea of exactly what you’re working with?
Matt
I found the velocity factor of my RG6/U on the manufacturer’s web site. I don’t recall what it was right now, but my elements ended up being around 116mm in length.
Will post some pics tonight.
Matt
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Does anyone know if it matter’s which direction the filter VBFZ-1065-S+ BANDPASS FLTR / SMA / RoHS EA is orientated in the system?
There’s no arrows nor identification on the filter and just wanted to make certain I put in in the right direction
The specs sheet doesn’t necessarily specify a feed direction, but the assumed proper setup would be the female SMA being the input and the male SMA being the output. Makes sense anyway as that’s likely the direction that you’d have adapters setup to put in in-line anyway. I had to snag a female-F to SMA-male adapter to make it work for me.
Found a killer deal on eBay on some of the best Mini-Circuits LNA amps available for ADS-B the other day, so my setup doesn’t look quite like the linked pic below anymore, but it does show an example of how I have the same filter in-line prior to my SDR dongle:
https://www.dropbox.com/s/t0uzsobounal7w1/0426150220-2.png?dl=0
(Disregard the temperature info at the top… This pic was also used in another thread.)
Sorry I didn’t get back to you on those messages from Friday… New baby coming home and things have been a bit busy.
Matt
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So the male end goes toward the Dongle?
On the MGX connector wire, is that a magnet you have on it after if comes out of the Dongle?
It comes out of the filter and goes into a ?
I doesn’t matter.
There’s no direction on these filters; at this power level they are symmetric.
bob
Thanks. I will be installing it tonight so hopefully it makes a difference.
PROBLEM…
I installed the filter VBFZ-1065-S+ BANDPASS FLTR / SMA / RoHS EA…
Now my plane count is down 35%
Any ideas on why?
We still need pics of your setup
Matt
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It’s possible that insertion loss has reduced the signal enough that some signals with marginal strength are now not strong enough. You may need to adjust your gain setting in dump1090 to compensate for it, if you weren’t already at the maximum. If you aren’t using an amplifier, then adding one at the antenna will most likely recover some of the weaker signals.
Are you able to determine whether your maximum range, or the area that you are able to reliably receive have changed? The raw message rate isn’t always everything - it may be better to accept a lower message rate in exchange for more reliable reception of the aircraft you are receiving.
I asked about some of these factors last week and am still not clear on his exact setup.
If he’s got the amp near the antenna and put the filter just before the antenna input on the dongle, the very low insertion loss of the filter shouldn’t be that big of an issue.
Matt
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