Perfect Vision Amp vs Nevis Computers 1090 Filter & Preamp..

FlightAware ADS-B Flight Tracking
1

Built an animated GIF to show the performance results between the Perfect Vision Amp & the Nevis Computer’s 1090 Filter & Preamp. For reference the larger coverage area is the Nevis Computer 1090 Filter & Preamp.

I’m happy with my results your mileage may vary. :slight_smile:
…Tom

2

That’s a nice boost in your reception. I’m actually using both, partly out of curiosity and partly due to laziness. I got the HABAmp and wanted to try it and I didn’t feel like going up to the roof to take down the PV amp. So I just added the HABAmp before the receiver. I figure the HABAmp’s filter will attenuate the signal a little and its amp will boost it back up. Adding the HABAmp did make an improvement. One of these days I’ll take out the PV amp and see how the reception is with just the HABAmp.

3

Both set-ups were/are installed at the receiver end of a 5m run of RG6 coax. I’ve thought about trying the Nevis unit at the antenna end of the coax run just to see the difference. Sort of waiting for a few dry days in a row as I don’t have anyway of protecting it from the elements yet.
…Tom

4

awesome the boost in your reception :open_mouth:

5

It’s this one, correct?
http://ava.upuaut.net/store/index.php?route=product/product&product_id=85

Are there any US retailers for this?

6

That is the one I have. As for NA retailers, none I got find, sorry.
…Tom

7

Hey glad to hear the Amp is working out for you (I’m the guy behind it).

You can get the ADS-B Amp in the States via airspy.us.

Obviously I also ship direct.

Cheers,

Anthony (hab.supplies)

8

Very high quality build and as you noted the amp works just fine. I will also note that shipping to Canada was very fast.
Thank you for your efforts, Tom

9

$45.95 + shipping as opposed to $7.99 shipping included…

14dB gain vs. 30db gain (what is claimed anyways…) seems the Perfect Vision amp got it beat there.
Nevis Computers offering has the filter built in is that effecting the results?
Would be interesting to see the comparison include a filter such as the FlightAware filter.

Nevis Computers 1090 Filter & Preamp: $45.95
“Perfect Vision Amp” & FlightAware filter: $27.94

Not dogging on the Nevis Computers offering just curious as to if the extra bucks are worth it. Especially being I am in the market for one being I am adding a UAT antenna and looking for an amp either for my 1090Mhz set up or one that will work with the UAT setup.

Heard a lot of good about the Hab products and honestly been looking hard at them. Love seeing comparisons made such as this especially when I am in the market. :slight_smile:

10

thanx tom - i ordered one instantly today :slight_smile:
regards
another tom

11

PV amp is a TV amp with a higher noise level, you may need a filter to go with it
HAB amp is lower noise and has the filter included

you might find ebay.com/itm/121678267330 to be similar to the HAB amp in performance - it has a SAW filter too, bit you would probably find that you would have to take the filter off and change it to a 1090Mhz filter (the one supplied on the board is probably 435Mhz)

12

I am in no way being negative about the other amp but we found in testing you can have too much gain. We did a prototype amp which used a pair of LNA’s in series to get about 30db of gain but there was actually a drop in performance as we just ended up overloading the radio. Unless you have a really long run of coax more than 15db of gain is probably going to have no effect and may in some circumstances reduce performance. As other posters have noted your mileage may vary RF is dependent on many factors (clue get good coax!).

Have a read of this ava.upuaut.net/?p=836 which I wrote a while ago.

I terms of cost we did recently bring the price of the amp down significantly, I appreciate its still a relatively expensive item compared to the cost of the RTL radios being used but it does both filter and amplify the signal and has been designed entirely around 1090Mhz rather than being “wideband”.

Cheers,

Anthony

13

if it really delivers - i think costs are absolutely adequate. housing and parts only i’d guess is at least 10-20$. so - 30$ for manufacturing, sale, warranty and support for a not-mass-production item is no big deal …

14

tom, thanks for sharing your experience. got my nevis/habsupplies amp from anthony some days ago. great little thing powered it from raspi usb and achived about 10% more aircrafts and 30% more messages. very good tip from you :slight_smile:

15

absolutely correct.

I installed a 20 db amp on one of our antennas running a flight aware feeder. Way up in the air and work to replace. Lost almost all close in positions (<50 miles). Fixed the problem by adding adding a couple hundred feet of cable to create extra losses without having to do antenna work.

A good reason to look at positions/aircraft instead of aircraft totals when monitoring performance

The PiAware is much more forgiving. I have not experienced a similar problem with them.

16

Ordered and installed Nevis Computers 1090Mhz ADS-B SAW Filter & Preamp For Dongles recently with excellent results. I’m using this in conjunction with Jetvision “A3 ADS-B” Antenna and 5m cable also from Jetvision. Filter/Preamp sits just before the dongle. Pi2, dump1090-mutability.

Times:

(1) Fri, 8th Jan, 20:00: Filter/Preamp installation (leaving dump1090-mutability gain setting at -10, i.e. maximum possible)
(2) Mon, 11th Jan, 10:20: set gain in dump1090-mutability to 45 with the aim to bring down the average max signal to around -3db

Signal increased too much with -10 setting but looks OK to me with 45 setting:

Message rate increased significantly with first change and increased again slightly with second change (but not obvious in this graph):

800×208 57.5 KB

Tracks graph looks most interesting. Change (1) brought a general increase of everything but the dialling back of the dump1090 gain to 45 brought down the junk ‘tracks with single message’ significantly:

Range increased slightly and aligns very well with heywhatsthat predictions:

This is where I get my longest range, aircraft entering/exiting the North Atlantic tracks. Heywhatsthat rings are at 30k and 40k foot. The example aircraft shown is at 38k and it nearly reached the 40k outer limit:
1024×406 83.3 KB

And finally, CPU consumption went up initially but dropped back significantly after the gain adjustment. I guess now it has less garbage to deal with and try to decode:

Overall, I’m very happy with the results and based on that can recommend the Nevis Computers 1090Mhz ADS-B SAW Filter & Preamp. I also like the fact that it can be powered easily with a USB cable.

17

@mgunther

Great write up and an excellent endorsement of the Nevis kit.

You say “(2) Mon, 11th Jan, 10:20: set gain in dump1090-mutability to 45 with the aim to bring down the average max signal to around -3db”

How did you get to the gain setting of 45?

Do you increment the gain settings up or down with


sudo dpkg-reconfigure dump1090-mutability

then stop/start mutabilty?
Thanks

18

I just guessed 45 and used


sudo dpkg-reconfigure dump1090-mutability

This already stops/restarts dump1090-mutability. When I have more time, I will try different settings but 45 seems to work pretty well in my environment. I seem to remember that -10 actually sets the gain to 49 (or close to it), so 45 seemed like a good starting point :slight_smile:

19

Have you tried setting the gain to agc?

I just setup dump1090-mutability on the weekend and remember seeing this setting.
If it works, it may reduce strong signal overloads for close traffic.

20

I believe the agc setting in the context of dump1090-mutability is actually equivalent to the -10 (i.e. maximum possible) setting. It does not actually perform any automatic gain control.