@ w7psk
Hmm. Those numbers seem low to me, even with a 25 foot run of RG-6. That should only be 2.5-3db of attenuation.
I was getting higher numbers with a 26’ run of LMR-200 which is actually inferior to RG-6 at this frequency. Curious to see how the prostick works out for you. Based on limited information and anecdotal experience I’m wondering it there’s something inhibiting your signal beyond the remedy of amplification.
@ w7psk,
Which antenna are you using?
If FA, then ensure that you have a 50 Ohm N Connector. The pin on the 75 Ohm version is small and may not make contact with the socket.
I agree the numbers look a little low for a short run.
Hope it’s ok that i hijack this thread with a question regardning my signal levels.
I’m not really sure how to read this figures, but my guess is that i have a lot of attenuation, probably mostly because the antenna cable, a cheap RG58 of around 45ft lenght.
http://forumbilder.se/F9HKK/dump1090-localhost-signal-6h.png
I’m running a dvb stick, with a 5/8 colinear antenna mounted on the rooftop, the antenna has really good sight all the way round. My house is situated at around 830 feet above sea level.
No, this is not the place the antenna is mounted right now. 
http://forumbilder.se/F9HKK/s-l1600.jpg
My gain is set at “max” right now.
I’ve ordered a pro stick, a Flight aware filter and a h155 low loss cable, but in the meantime, is there anything i can do to improve the signal quality?
Regards from a newbie in Sweden 
Home made 8 elem Coco. I’ve built tons of ham antennas so pretty good at it.
Yep that’s about 10dB of attenuation right there…
RJ58 has around 21.5db loss per 100 feet.
45 feet = 9.675db loss.
Only about 10% of the power is getting through.
h155 low has about 30.9dB per 100M (328 feet).
45 feet = 4.25 db loss.
about 37.5837% of the power will get through.
almost 4 times the RJ58
Yeah with a run that length you might do well with a satamp at the antenna. But that’s not always feasible.
I’m not familiar with H155 but if the specs matched what I’ve found online you should see a huge improvement.
Not as much as with my beloved CA400 :mrgreen: but still. A huge improvement. Especially with the amp in the prostick.
Well, i guess i can live with this for maybe a week, hoping to get the new stuff delivered soon… And also hoping to see some huge improvements of the signal.
If you look at my signal level chart, what is a “good” or “acceptable” level, so i know where i shall aim once i get the new stuff installed?
New stuff installed. Pro stick and FA filter, 29ft of Aircell 5 coax.
Running gain at -10 right now.
Any comments and thoughts on my levels?
http://forumbilder.se/F9I0P/dump1090-localhost-signal-1h.png
Hard to say from just your signal level, but looks like it might be running a little hot. I would see if your message rate improves at like 45
I can’t believe mine runs just as well at 30-35 as it does at max. The noise floor drops 10db.
I only started testing yesterday but will make only one change at a time.
I have a big DPD antenna and a short coax run (2’) at the moment.
Before I was Pi2-SilverRTLDR-inlineamp-25ftcoax-antenna.
Now
Pi2 - FAPro - 25ftcoax- antenna
I was adjusting the gain you can see things change but ended up back at -10 it seems to give me the most planes. Should I leave it or change it?
I would leave it at -10 (which is the maximum possible). Your messages over -3dBFS are very low. Not many signals are overmodulating.
It looks like (and this is largely a guess) that the biggest thing inhibiting you at this point is cable run loss.
Your two options:
Still have that inline amp? Try mounting it at the antenna end, and recalibrating gain on the prostick.
Upgrade your coax.
(incidentally, what kind of coax are you using?)
Sat. Quality RG6.
Look at my stats here:
And if someone please can explain the whole gain thing to me. Why shall i try to keep messages over -3dbfs at a minimum? Is it because the receiver gets “flooded”?
How did you get the receiver panel graph, I don’t see that in my ADSB receiver portal graphs??
Jeff
How did you get the receiver panel graph, I don’t see that in my ADSB receiver portal graphs??
Jeff
