Poor stats on FF box as compared to Radarcape

I’ve just installed a Radarcape box that sits besides my FF. The antennas are about 30 cms apart. The first thing I noticed was that the Radarcape box reports at least 6x aircraft, a better message count and range. To rule out the issue of bad antenna, I temporarily switched antennas and while the stats on the Radarcape dropped marginally, there was NO improvement on the FF box stats.

I am wondering if this is pointing towards a hardware or software issue inside the FF box, the bad antenna issue notwithstanding

The radarcape is an exceptional receiver - but this is reflected in how much it costs.

I agree Radarcape is pretty much top of the line, but the FF runs a Rpi and an Nuand BladeRF SDR. The BladeRF board retails $450, so I would have assumed that the FF box would perform comparably

radarcape include saw filter on frontend,and FF dont have it…

If you install the filter and amplifier MMIC I believe FF will be a winner with the same antenna…

I hope FlightAware take steps to rectify this. A class piece of hardware being underutilised is quite a waste otherwise.

You likely were impacted by a defective batch of antennas. Did you receive an email from FlightAware about coordinating a replacement?


You could try swapping the antennas to test.


I did swap the antennas to check as I had received an email. I plugged in the FF to the Radarcape antenna and vice versa. Test confirmed that the antenna is defective as the stats immediately fell on the Radarcape but there was no noticeable increase of stats on FF.

Therefore I concluded that not only is the antenna defective but also there could be some potential issues with the FF box.

AS I write this both my systems are up and are running off each other’s antennas. FF shows 3 aircraft while Radarcape is showing up 14

So the new FF design is lacking a 1090 MHz saw filter? That was a big mistake in my opinion… the reason being is now the front-end of the receiver will be susceptible to overload from cell phone towers. This could be the case with clipsnotebook FF problem.

Anyone else notice a similar issue? You may be right - there is no SAW filter and that could be messing things up. I am hoping FlightAware will investigate this issue.

Do you have any cell phone towers or UHF TV transmitters near by you?

No cell phone towers in sight for at least one KM.

Most cellphone operators in India operate in 1800 MHz band whilst some still operate in the 900 MHz band and I doubt this will impact as much. I really cannot pinpoint to the source of this anomaly and turn to the experts here on the forum and at FlightAware to help me figure out what needs to be done.

Those in the 900 MHz band (especially those close to 950) can severely impact ADS-B performance at 1090 MHz; with many of the small SDRs, there’s a significant drop off above 1800 MHz, so those, and Wi-Fi in the 2.4 GHz band don’t matter as much.

So here’s the comparison using VRS. The range circels are 50 kms apart. Radarcape’s range is at 450 kms and the FF box barely touches 150 kms. This sample was taken over the last few hours.

There was a fr24 user with a radarcape, which is a well shielded radio. He had no issue with the radarcape for over a year until he installed an AIS Ship tracking system. en.wikipedia.org/wiki/Automatic_ … ion_System

AIS uses 2 VHF frequencies, maritime channels 87B (161.975 MHz) and 88B (162.025 MHz)
He installed the VHF AIS antenna on the same mast as the ADS-B antenna about 2 feet apart.

When the AIS system was on the radarcape had very poor range. At first he thought it might be the close placement of the 2 antennas to each other. Moving the antenna far apart made no difference.

Moving the AIS and Radarcape radios, which were stacked on top of each other in his office, fixed the problem! If the Radarcape is within 1 meter of the AIS radio it would lose range. What was discovered was the 2 radios, even if they received frequencies that were worlds apart, they both used the very same Local Oscillator frequency and they were interacting with each other if they were too close together. Even with good shielding a ‘leaky LO’ can cause a problem.

Thanks - I will now try increasing the physical separation and post the results here. currently they sit about 20 cms apart.

I have moved the receivers approx 1.5 meters apart and there is a marginal improvement in the FF box’s range. However, still it is nowhere close to my Radarcape in terms of coverage and range. Here’s a comparison:

After running just the FF box (I switched off and packed away my Radarcape) for two days in a row, I see no improvement in the stats. The Radarcape interference has not been an issue as the Radarcape box is disconnected and not in the FF box’s vicinity.

Please can someone from FlightAware assist?

Hi clipsnotebook,

found you via your post in the topic about the replacement antenna’s.
Today is concluded that i have the same problem as you have. The new antenna seems to be working perfect with radarcape(FR24) but the range is very limited with the new antenna and with the antenna from my radarcape.
I’ve Contacted support about this.