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FM Overload

M

MarioMania

I just wanna ask if this is FM Overload or just bleeding in

When I go out to look around I bring my Sony WM-FX10 Walkman to listen to the Radio

But, Most area in Sacramento, I get Bleed from Hot 103.5 on open Frequency , Some not..Like I'm trying to hear 98.1 coming in and coming out

It doesn't happen often ..But it kinda strange
 
Can the difference frequency of 5.4MHz between those two stations be
getting doubled inside his radio and finding its way into the IF amplifiers?
 
MarioMania said:
I just wanna ask if this is FM Overload or just bleeding in

When I go out to look around I bring my Sony WM-FX10 Walkman to listen to the Radio

But, Most area in Sacramento, I get Bleed from Hot 103.5 on open Frequency , Some not..Like I'm trying to hear 98.1 coming in and coming out

It doesn't happen often ..But it kinda strange
Click to expand...

Try using the DX/Local switch and switch it to "Local" if you have severe problems with the bleedover. That's what the switch is for.

FM overload is very common in a lot of radios -- walkmen radios, boomboxes, table radios etc: the radio's RF circuits just aren't designed to handle the high power of many FM signals, which can sometimes be 50-100 KW ERP. You're probably located close to the transmitter sites.

Some areas of a metro will have 'dead spots', where the signals are lessened for various reasons: terrain, nearby buildings, etc.

On some of my radios I get bleedover from FM stations. Sometimes I have to turn the antenna away from the transmitter site. On one radio I have to collapse the antenna. Your walkman probably gets FM off of the headphone cord, so you can't do that.
 
The model you mention appears to be a current model. Sony's old standard superhet design appears to have made an unwelcome return - I much prefer their CXA-1129 based designs such as the SRF-59. Their standard superhet design has one cheap FM ceramic filter for FM, and that means that the stopband rejection is no more than 40 to 50 dB. That invites overload and crosstalk - any FM station 1/100 of the power of the one you are trying to receive (after the antenna tune section) absolutely WILL punch through and mix with the station you are interested in, and definitely on blank frequencies. You can possibly alleviate this by replacing the single ceramic filter with two - provided the AGC range of the radio will boost an additional 9 dB or so.
 
rbrucecarter5 said:
The model you mention appears to be a current model. Sony's old standard superhet design appears to have made an unwelcome return - I much prefer their CXA-1129 based designs such as the SRF-59. Their standard superhet design has one cheap FM ceramic filter for FM, and that means that the stopband rejection is no more than 40 to 50 dB. That invites overload and crosstalk - any FM station 1/100 of the power of the one you are trying to receive (after the antenna tune section) absolutely WILL punch through and mix with the station you are interested in, and definitely on blank frequencies. You can possibly alleviate this by replacing the single ceramic filter with two - provided the AGC range of the radio will boost an additional 9 dB or so.
Click to expand...

I think the WM-FX10 is an old 1990's / early 2000's model. I saw one advertised on EBay as "vintage".

I have one that's similar (the WM-FX101). It came out in the late 1990's or early 2000's, I think. It might have a CXA-1019 chip. With an external loop, it can DX OK on AM.

What Mario might want to try is a headset with a shorter lead, that might cut down the signal strength a bit. Or just use the DX/Local switch (if the radio has one -- not sure if the WM-FX10 does) set it to local.
 
It's obviously 'cause you're so close to the transmitter. Just the breaks.

I have the WM FX101 (checked the model # since my last post). No DX-local switch, so I doubt yours has one. A couple years ago I DXed the AM Band with it, with a Radio Shack loop. Good sound, DXed OK. Nice Walkman.
 
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