• You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
  • The Feb 2025 Radioddity Giveaway Results are In! Click Here to see who won!

Noise Floor on SS3900

HomerBB

Sr. Member
Jan 4, 2009
3,940
2,679
273
68
Rogers, Ar
I picked up a SuperStar 3900 Plus and find it to have about the noisiest receive of any radio I've owned. The white noise is terrible. I managed to bring the noise level down on my 959 while improving the receive by simple adjustments within the radio. The question here is whether anyone knows where or what I can do on this EPT360010 board to accomplish an improvement. I have found a mod that enhances receive, however, it is said to make it sensitive to the point of potentially causing harm to the receive of the unit should a loud audio signal nearby be keyed into it.

Any hope for quieting the white noise down without losing receive?

Thanks,
Homer

Looks like this:
images
 

I picked up a SuperStar 3900 Plus and find it to have about the noisiest receive of any radio I've owned. The white noise is terrible. I managed to bring the noise level down on my 959 while improving the receive by simple adjustments within the radio. The question here is whether anyone knows where or what I can do on this EPT360010 board to accomplish an improvement. I have found a mod that enhances receive, however, it is said to make it sensitive to the point of potentially causing harm to the receive of the unit should a loud audio signal nearby be keyed into it.

Any hope for quieting the white noise down without losing receive?

Thanks,
Homer

Looks like this:
images

Hello:

I have the same radio and I did this mods to mine,works pretty good

RX Sensitivity
Change R44 100K to 39K
Change R46 39K to 100K
***Just swap both resistors***

D20 to Schottky
D21 to Schottky

Change R81/100 Ohms to 180 Ohms (DONE)
***Improves Noise Floor,Lessens Stage Gain***

Try this mods at your own risk


73 de Tecnicoloco
 
Hello:

I have the same radio and I did this mods to mine,works pretty good

RX Sensitivity
Change R44 100K to 39K
Change R46 39K to 100K
***Just swap both resistors***

D20 to Schottky
D21 to Schottky

Change R81/100 Ohms to 180 Ohms (DONE)
***Improves Noise Floor,Lessens Stage Gain***

Try this mods at your own risk


73 de Tecnicoloco

Thnx!
What might the risks be? Any in particular, or just the general warning issued with all mods?
 
I would have a good shop do a proper alignment on it first and see if that helps. Since it's a 10m Export it was probably just converted, the receive needs to be aligned for 11m use.
 


Write your reply...
dxChat
Help Users
  • No one is chatting at the moment.


      You do not have the permission to use the chat.