Archer ACCESS receivers

[Tim Kearsley]

Has anyone had experience with using any of the Archer receivers?  I've just installed an R10 Pro in a Hangar 9 Spitfire.  At the field on Thursday I did a range check, thinking it would be a formality really.  Nasty surprise - RSSI in range check mode dropped to critical level within 20 or 30 feet.  I know the RSSI scaling seems to be different with the ACCESS receivers and I'd set the alarms to 35dB for warning and 31dB for critical.  However, checking the control surfaces indicated that signal was lost within 40 feet or so.  So, no flying! 

At home, I took the cover off the Rx and removed the antennas and replaced them.  The situation now seems better.  In general though, does the indicated RSSI drop off more quickly than with the ACCST receivers?  I'm wondering about setting up a warning using a combination of low RSSI and low VFR - say anything below 35dB combined with a VFR below 80%.  What do you think?

 

[EarlyBird]

When doing the range check was the model on the floor?

[Tim Kearsley]

18 minutes ago, EarlyBird said:

When doing the range check was the model on the floor?

Yes it was EB.

[Hangarqueen]

I always do a range check with the model about 1 meter above the ground, in "all" directions (I rotate the model on a stand and do the range check again) to detect any reception blind spots.

Vegetation like grass (anything containing water basically) blocks out a 2.4 GHz signal in a very effective way, so make sure there isn't anything like that between transmitter and receiver.

[EarlyBird]

Just rang a bell from when I first switched to Frsky and telemetry.

 

The model needs to be more than two feet off the ground, I assume the ground (especially wet grass) reduces the signal strength. When in range check my surfaces moved as expected at 100 ft even though RSSI was low. Never having had telemetry before and always flying without issue based on the range check I flew obviously without issue.

 

I have been told that RSSI going critical is not a problem as the model will continue to respond up to twice the distance but telemetry will be lost. With this in mind and knowing that the receivers are good for up to 2 km I found that the low alarm would sound at some 400m I could not test the critical alarm as the glider was becoming a dot in the sky. 

 

Based on this experience I am thinking all this technology is getting in the way of the fun. Thinking about it now I can not remember the last time I looked at the RSSI, alarms have never sounded, and I have switched off the telemetry recording. I have gone back to the idea that if it's in sight then it's in range and happy at that.

 

Steve

[Tim Kearsley]

I agree that it's all too easy to get hung up on telemetry.  Some is very useful, such as consumed mAh, if you fly electric.

With the advent of the ACCESS protocol FrSky have made available the VFR (Valid Frame Rate) metric.  I believe it equates roughly to a measure of link quality.  It's why I am considering configuring a warning if both RSSI and VFR drop below a certain level - it might be a better way of identifying a real low signal scenario.  That said, I can't remember ever having signal problems in about 16 years of RC flying!