26-10-2018, 11:48 AM
Hi Craig,
working out all the possible answers for image freq can be quite a chore, you also have to consider if there is any bleed through to your 3rd IF (455KHz in you case) as it sounds like you are in an area getting extremely strong primary signals.
I only mention this as I had a VHF receiver listening on 52.525 MHz that used to burst into life with the Radio Australia standby tones (Waltzing Matilda) when they used one of their 10 MHz frequencies I think it was. (over 30 years ago now). This shortwave transmission found its way through the VHF front end and ended up as an image in the I.F... this took me weeks to work out how my VHF receiver was playing Waltzing Matilda to me at certain times of the day.
Good luck with your journey but be prepared for the possibility it is caused by another external factor like another AM station.
Peter, vk5pj
working out all the possible answers for image freq can be quite a chore, you also have to consider if there is any bleed through to your 3rd IF (455KHz in you case) as it sounds like you are in an area getting extremely strong primary signals.
I only mention this as I had a VHF receiver listening on 52.525 MHz that used to burst into life with the Radio Australia standby tones (Waltzing Matilda) when they used one of their 10 MHz frequencies I think it was. (over 30 years ago now). This shortwave transmission found its way through the VHF front end and ended up as an image in the I.F... this took me weeks to work out how my VHF receiver was playing Waltzing Matilda to me at certain times of the day.
Good luck with your journey but be prepared for the possibility it is caused by another external factor like another AM station.
Peter, vk5pj