Receiver problem or just poor filtering

[JS6UEY]

I have an old ALINCO (Japanese domestic version of the DR-605) that has significantly worse VHF reception than my Yaesu FT-857.

I'm trying to get a band pass filter to test the ALINCO; however, until then is there a way to recognize by the signal differences whether it's a problem with the ALINCO's receive module or just poor filtering?

73
JS6UEY