If I'm inside, I use my PRO-106 connected to my GMRS j-pole
It actually performs pretty well as a scanner antenna, I monitor rail, civil air, & mil-air, for being tuned to GMRS, it doesn't do a bad job
When this heat finally breaks, I'm going to put up a separate scanner antenna
The GMRS J-Pole is tuned for maximum performance on the 462 - 467 MHz General Mobile Radio Service and UHF public safety band. This is a full Power GMRS antenna that will work great with handheld and base units. Don't be limited in performance by VC encased wire antennas. GMRS radios are...
www.jpole-antenna.com
When I start scanning in the car, I have an E/M Wave commercial tri-band NMO EM-M43002 on a JetStream mag mount
https://www.emwaveinc.com/antennas.php?page_id=86&item_id=237
If I'm portable, I alternate between two Part 90 h-t's, an Alinco DJ-A10 & an Icom IC-F50, each has a Laird 150-162 MHz 10.5" loaded quarter-wave with SMA-F & SMA-M connectors respectively
Manufacturer: ICOM; Frequency Range: 150-160 MHz; Length: 10.5"; Construction: Molded; Antenna Type: 1/4 wave base loaded; Connector: SMA Male; Warranty: 5 Year
theantennafarm.com
I'm going to buy a Smiley 5/8 Slim Duck 155 MHz to rotate between the two h-t's, I usually use them for MURS at work, but I think for rail receive, it should be pretty close, preferably an upgrade from the 1/4 wave
5/8 SLIM DUCK Super efficient VHF antenna show a OMNI directional 6 dbd gain flexible base loaded antenna, manufactured tough enough for the military and aesthetically pleasing for the consumer. Sealed in synthetic rubber and utilizing the Tuned Antenna's one piece NT-MIL Space Age covering system (
www.smileyantenna.com
Smiley has the link wrong for some reason, but this does take you to the 155 MHz 5/8 Slim Duck page
Anyway, that's what I use right now for rail monitoring
73