Preselector's ?

[Nightshade]

I'd like to help my Grundig 800 a bit with background hash so I'd like to add a passive preselector to the antenna input to take some of the strain off the 800's front end.

So far I've narrowed it down to two preselectors.....The MJF-965 & the MJF 1046. The 956 is simple with the 1046 also being simple but more polished in it's function.

What I need now is some input from those here that have either used these preselectors or own/use one now. Will these preselectors help or not?

 

[N8YX]

Not familiar with either of those two, but Yaesu, Palomar and Ameco offered both passive and active preselectors at one time. If MFJ's designs are functionally similar to those, you can expect about 10-15dB of out-of-band rejection on both sides of "tuning center".

Is the undesirable signal located at one frequency or is it truly a broadband "hash", such as the RFI generated by a plasma TV's power supply?

 

[Nightshade]

Not familiar with either of those two, but Yaesu, Palomar and Ameco offered both passive and active preselectors at one time. If MFJ's designs are functionally similar to those, you can expect about 10-15dB of out-of-band rejection on both sides of "tuning center".

Is the undesirable signal located at one frequency or is it truly a broadband "hash", such as the RFI generated by a plasma TV's power supply?

I don't know just what the hash is but I'm out on the enclosed front porch away from all the electric goodies that might cause interference.

Just trying to "clean up" the signals a bit so I can hear better.

 

[N8YX]

Sorry for the long delay in responses. For dealing with the sort of EMI 'hash' you're experiencing, I would have a look at MFJ's 1025/1026, Timewave's ANC4 or DX Engineering's antenna phasing units. These allow you to use a sense antenna for phase-cancellation purposes and will make short work of most EMI/RFI sources.

Of course, some caveats apply: The main and sense antennas must have roughly the same gain at the frequencies of interest, or else you won't get an effective "null" of the interference.

I use a 1026 at my SWLing post, and am putting together an amplified, 'broadband' (1-35 MHz) whip for use as a sense antenna.

 

[Nightshade]

Sorry for the long delay in responses. For dealing with the sort of EMI 'hash' you're experiencing, I would have a look at MFJ's 1025/1026, Timewave's ANC4 or DX Engineering's antenna phasing units. These allow you to use a sense antenna for phase-cancellation purposes and will make short work of most EMI/RFI sources.

Of course, some caveats apply: The main and sense antennas must have roughly the same gain at the frequencies of interest, or else you won't get an effective "null" of the interference.

I use a 1026 at my SWLing post, and am putting together an amplified, 'broadband' (1-35 MHz) whip for use as a sense antenna.

I'll look into the 1026 but I've got to be careful not to cause signal overload since my SWL'ing is all on portable type radios. So far MFJ has recommended that I stick with a MFJ 1046 Passive preselector. However, since SWL is 9/10 experimenting I'll keep the 1026 in mind if the 1046 doesn't work as well as I'd like.

 

[TedMcC1]

MFJ-1046 Passive Preselector

Did you ever end up purchasing the MFJ-1046 passive preselector? I bought one a year ago and have never been able to get it to work. It seems so simple. I even emailed photos to the company and asked them if I was setting the dials correctly and they said that I was. Still, doesn't work. Has anyone used it successfully?