Author Topic: Is it OK to power up Rosetta with no Antennas connected?  (Read 1920 times)

Etheav8r

Is it OK to power up Rosetta with no Antennas connected?
« on: February 22, 2021, 12:27:27 pm »
I am nearing completion of the installation of the remote antennas in my Jabiru, which means it will soon be time to power up and configure my Rosetta for the first time.

I just want to check that it is OK to powerup the device without any antenna connected?  The reason I as is I also have multirotor R/C models with cameras which connect to a Video Transmitter (VTX) and if the craft is powered up without an antenna connected to the VTX, the TVX is very quickly damaged beyond repair.

Many thanks

exfirepro

Re: Is it OK to power up Rosetta with no Antennas connected?
« Reply #1 on: February 22, 2021, 01:57:00 pm »
Hi Edmund,

The 1090 side is fine as it’s receive only, but running the 869.5MHz side without an antenna certainly isn’t recommended as this side includes the P3i transmitter.

If you only want to do a temporary power-up, you can set ‘Aircraft Type’ in the Configure Page to ‘Base Station Rx Only’. This will disable the P3i transmitter but leave the rest of the unit operating normally. Remember to set it back to the correct aircraft type afterwards though or you won’t be transmitting your position and won’t trigger uplinks from PAW ATOM Ground Stations.

Regards

Peter


Etheav8r

Re: Is it OK to power up Rosetta with no Antennas connected?
« Reply #2 on: February 22, 2021, 09:08:02 pm »
Thank you Peter.

Edmund

TimT

Re: Is it OK to power up Rosetta with no Antennas connected?
« Reply #3 on: November 20, 2022, 07:29:57 pm »
I am running version 20220805. Checking on the configuration I found that Aircraft Type = Base Station is no longer available in the pull down menu for this field.

Is that correct?

Admin

Re: Is it OK to power up Rosetta with no Antennas connected?
« Reply #4 on: November 21, 2022, 07:55:46 am »
Hi Tim
That is correct
Base station capabilities are fulfilled by the ATOM basestation
Thx
Lee

exfirepro

Re: Is it OK to power up Rosetta with no Antennas connected?
« Reply #5 on: November 23, 2022, 11:53:35 am »
Hi Tim,

I wasn't aware of that change myself, though I suspect it was made quite a while back.

The option to run individual PAW units as Base Stations was very useful in the early days when we needed 'actively transmitting' ground units to test airborne PAWs but that need has essentially been removed because of the ready availability of 'active' PAWs and of the custom designed ATOM Ground Station software. (but see below)

That, however, still leaves your question re 'testing your PAW without antennas' essentially unanswered.
 
The reason we shouldn't run transmitters without an effective antenna (or equivalent matched impedance 'dummy load') is to prevent damage to the output stage of the transmitter by the transmitted signal having nowhere to go and being reflected back into the transmitter. This is particularly important with high-power transmitters, though less so with PAW.

The significant change, however, is that PAW software has for some time now included an 'Aircraft Transmit Speed' feature (on the 'Configure Screen' just below 'Aircraft Type'). This was originally designed to prevent transmissions from essentially 'non-moving' aircraft on the ground - in order to reduce 'clutter' on displays and repeating audio alerts received by aircraft in close proximity (e.g. in the circuit). The 'Base Station' options were presumably removed at the same time, or shortly afterwards, though as I say I wasn't aware until now that this had been done.  :-[

The trigger threshold for Aircraft Transmit was originally set at a default of 10Kts* - which means that PAW wouldn't transmit when not moving, or when taxying extremely slowly, but I can't recall if this default is still current, so my advice would be to power up and go straight to the PAW/ Config Screen and check this setting. If it isn't set at 10Kts (or higher) set it to this level and your unit won't transmit unless it is moving at this speed or above. Remember to review your setting if you decide you do want your PAW to transmit when not moving (e.g. for testing) once you have connected the appropriate antenna, but please reset it to a sensible threshold before actual use.

*Remember that aircraft such as helicopters may need to set this threshold lower than 10Kts to keep PAW transmitting while in the hover.

I hope this helps clarify the situation.

Best Regards

Peter