Should I buy a Raspberry Pi 3B+ or 4B?

RemoteTx will perform equally well on either a 3B+ or 4B. Currently, the additional memory and features of the RPi 4B do not make a noticeable difference for RemoteTx operation. In the future it is possible that new RemoteTx features could be added that would take advantage of additional memory an performance that a 4B can offer. The RPi 4B is rather new and it has been noticed that it generates more heat than the 3B series. While under normal conditions it should not overheat, time will tell if there are any heat related issues with prolonged operation in warm operating environments.

What Browser should I use?

On Windows, Mac and Linux the best choice is Google Chrome. On Apple iPhone and iPad IOS devices use Safari (iOS 11+). On Android phones and tablets use Google Chrome. Chrome OS uses Chrome.

Will a single RemoteTx subscription work with multiple stations?

No BUT… A single subscription enables 1 Raspberry Pi connected station to be controlled at a time. Using the same license key simultaneously on multiple stations/RPi’s will cause unpredictable network and control behavior. BUT… if only one RPi is powered on at a time, 2 RemoteTx RPi’s could have the same key at 2 different locations and the station with the powered-up RPi would be the one available for control.  Just make sure they are not both turned on at the same time.

Can multiple radios be connected to a single Rpi at the same station?

Yes, but only one can be used at a time. A careful operator will be able to select and control multiple radios all plugged into the same RPi. This is where the RemoteTx power control options can be very useful. Multiple radio serial port controls will show up under the USB Serial Ports list under the Setup tab. Multiple radio audio sound cards will show up under the Audio tab. Be CAREFUL not to transmit a strong signal with one radio that could damage a second radio that is turned on. Of course antennas will have to be configured and managed like any other multiple transmitter station.

Will RemoteTx work on Wifi?

Yes. By default, Wifi is not activated on a newly downloaded RemoteTx Raspberry Pi SD Card.  Initially the Raspberry Pi needs to be connected to an ethernet network when it is booted to make the Wifi configuration interface available. After Wifi is successfully turned on and configured the ethernet network can be disconnected and RemoteTx will continue to function on Wifi.
See:  Operating Notes-Wifi

Can RemoteTx be used with Digital Modes?

Yes, with some additional components (Signalink, RigBlaster etc) and computer setup (virtual audio cable). RemoteTx has successfully been configured to operate PSK31, FT8 and Winmore Winlink with RMS Express. Basically, if the digital mode software can be configured so that all interaction is through the sound card, RemoteTx should work on a low latency network. The TX/RX keying needs to be done using VOX with a device at the radio such as a Signalink or Rigblaster. This is similar to what you would do if the computer were connected to a Signalink at the radio station. In addition, a virtual audio cable (https://www.vb-audio.com/Cable/) software driver will need to be installed on the computer to assist in routing sound in the correct direction to and from the Rpi. Contact RemoteTx for more information if you are interested in this.