[Boatanchors] Low Pass Filter Issues

[Duane Fischer, W8DBF]

Hello All, 	
	
Today I listened as several Hams in a local ham supply store argued about low
pass filters. It was for a two meter VHF transceiver. One insisted the filter
had to be for VHF use only and would severely inhibit a HF rig from
transmitting. Or the converse, that a low pass filter for a HF rig would
severely inhibit a VHF rig from transmitting. Another said the same low pass
filter would work on either a HF or VHF rig. What exactly is the truth here? 	
	
Nowadays many new HF transceivers come with a low pass filter included in the
design. How effective are they as compared to the external ones?	
	
Do any VHF rigs include them nowadays?      	
	
Thank you for your wisdom. 	
	
Duane W8DBF