Sangean WR-2 FM Stereo Problem

[lewischange]

I just purchased a Sangean WR-2 AM/FM radio. I am very happy with this radio except for one problem. All the FM stations that are broadcasting in stereo sound fine with excellent stereo reception, except for CBC Radio 2 at 103.3 MHz. It only receives in mono. It is not a signal strength issue as the signal is very strong. I've also tried the radio at several different locations (work and home) and the results are the same. Does anyone have an idea why only CBC Radio 2 at 103.3 MHz does not receive in stereo on this particular radio?

[stampeder]

Please tell us where you are. Also, some CBC FM stations broadcast in mono, believe it or not. CBC Radio 1 in Vancouver on 88.1MHz is mono, while CBC Radio 2 at 105.9MHz is stereo with RDS data.

[rob50312]

Many CBC stations broadcast in mono only

[BGY11]

Actually, it's my understanding that CBC Radio One (usually) broadcasts in mono, but Radio Two is always in stereo. I'm presuming you are in Ottawa based on the fact CBC Radio 2 is on 103.3MHz.

[lewischange]

I live in the Ottawa region. CBC Radio 2 is broadcast in stereo here. I have a second radio to compare (not a Sangean) and the audio is definitely stereo.

I'm an amateur radio operator with a background in RF and this one has me stumped!

[stampeder]

With that info we'll definitely take your word for it then! What an odd situation.

[CamDAB]

The DAB / FM palm sized radio does this too... But it randomly changes it's victims to do it to.... :-)

Sometimes, all stations are decoded in stereo correctly. Sometimes, it picks on CHUM-FM from Toronto, other times, Virgin on 99.9 Toronto, but some stations NEVER get hit with the mono bug.

Can't tie it to signal strength, multipath, temperature or humidity.

It never had any physical abuse... It's done this since day one.

On a station that's in mono, punch the up button once (the FM section goes up in 50KHz increments) and the stereo indicator comes on. Go back on channel, and it goes out. This can be done on any affected station. Next day, the station in mono will be perfect, but another one will be affected.

Yet on all other radios here, the affected stations can be received perfectly in stereo.

My suggestion to the OP: Return the radio for a swap of the same brand / model. Sometimes these things can be sample specific. But sometimes not.... YMMV.....

Cameron

[lewischange]

Cameron,

Thanks very much for your reply. I wish this problem was not happening to your radio as well but I am somewhat happy to hear that my radio is not the only radio with this strange problem. So far on my radio only CBC2 at 103.3 MHz appears to be affected.

I wonder if the DAB/FM palm sized radio you have contains the same AM/FM decoding IC: Toshiba TA2099F?

I may inquire about taking the radio back but I bought it from a small dealer here in Ottawa with a 25% restocking fee and to get me the radio they had to order it from the 'warehouse'. Warehouse is in quotes because I doubt they have a warehouse full of these radios.

I do have the schematic and service manual so I am tempted to have a look at some of the signals inside the radio. Especially the 19kHz signal that is mainly responsible for FM stereo decoding. If I find out more I'll post it here.

[CamDAB]

^^^
Can't say what's in the radio, the FM is primarily designed for the U.K. / EU market, but with a DAB section designed for Canada only, thus the FM having the 50KHz steps.

The FM isn't very sensitive (I suspect internal noise), requires a very high signal strength to pop it into stereo (yet the stereo indication will come on even when a weak stereo signal is present). Finally, it has a whopper of a birdie at 98.3 MHz... Full quieting... two bars on a 4 bar scale... This was my second DR-101LF that I had... The first one had a DAB section that would fail when the unit got warm. Both radios had EXACTLY the same FM characteristics, like they were cookie-cutter made. Including the birdie. :-)

Compare these FM behaviors against your receiver and see if there are any similarities.

Cameron

[eleakist]

Lewischange wrote regarding stereo broadcast issues with CBC Ottawa 103.3 and was concerned that his new tuner was defective. I noted the same issue at about the same time but did not sit down until today to sort it out. In my case, I pulled one of my vintage FM tuners off the shelf for some outdoors listening time on Canada Day. I had no stereo beacon at 103.3 so, like Lewischange, blamed first my temporary antennae and them myself for not using the tuner more often. Today, back indoors, with a dipole, an ST2, and a Winegard 13 roof mounted antennae there is no stereo on 103.3 on any of my tuners in several locations in the house, despite antennae orientation. CBC 103.3 has simply stopped broadcasting in stereo within the last week. Tuners tested included a Crown FM2, McIntosh MR74, and MD100. Not my tuners, as stereo reception is fine on all other stations, so has to be 103.3 CBC Ottawa

[stampeder]

Also what is your location, eleakist? lewischange, where are you?

[eleakist]

I am east of Ottawa, on the escarpment between Orléans and Cumberland.

eLeakist

[stampeder]

Thanks, we'll see if he's nearby you in case there is some strange mojo affecting the Sangean in that particular area. Otherwise we're back to square one.

[lewischange]

Well, CBC 2 at 103.3 Ottawa now comes in stereo on my Sangean WR-2. I have not changed anything with the radio. I did send a message to CBC some months ago about this problem but never got a reply. I haven't tried the radio for a few months so i do not know when the reception went from mono to stereo on the Sangean.

Since, at the time, location and antenna did not have an effect on the mono/stereo reception, I do not have an answer as to why the signal is now being recieved in stereo. Since stereo reception on the radio is dictated by the presence of a 19kHz pilot tone, my only guess is that CBC has made a slight modification to the level of this 19kHz tone.