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Conion C100F low to no FM Stereo

l.lopez - 2009-03-10 21:50

Hi fellas hope ya can help me, I have this Conion C100F that barely picks up FM Stereo most the time is mono. Is there is a way I can adjust the FM signal from inside? Or good old contact cleaner should do the trick? Please help thanks Smile.

baddboybill - 2009-03-10 21:54

deoxit has been working for me Big Grin

blaster - 2009-03-10 22:20

antennas inside connected?

moncheeto - 2009-03-11 02:55

lopez try deoxit on the band switch i had to do that to a conion that was acting up on the radio portion, so once you open the back i guess you can get to it and on the way see if everything else is in order Nod Yes

kittmaster - 2009-03-11 05:02

Also note the position of the pot, deoxit and spin it several times and return it to position before you moved it, that many times also corrects this issue.

isolator42 - 2009-03-11 15:13

with my M90 there was a pot on the tuner board that cured this exact problem.
Here's the post:
http://stereo2go.com/eve/forum...491037225#6491037225

...maybe there's a similar pot on the FM tuner circuits in your Conion?

l.lopez - 2009-03-11 16:55

Thank Ya all, I'll open the Conion up spray inside and I have to see where is this pot control Smile. Thanks again Big Grin.

isolator42 - 2009-03-12 10:40

what's needed here is the service manual. I'm sure someone had that available for download on rapidshare?

superduper - 2009-03-22 12:47

A small word of caution regarding the use of tuner cleaner or deoxit on tuners. All too frequently, I see suggestions to use tuner cleaner on a poorly performing tuner. While it is perfectly fine to use them on those small PCB mounted pots, do not confuse and use these solvents on the variable capacitor. This would be the large square box that actually does the tuning. If you get any fluids in there at all, you will likely lose AM/FM completely until the fluid dries up and because they aren't open, it could take a very very long time. Also, most cleaners do not evaporate 100% and a film remains afterwards. This film may change the capacitance characteristics of that component.

As to the 19khz adjustment, by far the best way to do this adjustment is with a frequency counter. This is the adjustment the pilot signal that allows the tuner to play stereo instead of mono. While it IS possible to do it by tuning to a strong stereo frequency and slowly manipulating the pot until you get a stereo "lock" this only guarantees that you'll get the stereo signal to "lock" on strong stations. I say this because with the assistance of a frequency counter, it is my experience that strong stations nearly always read 19khz but when tuned to a weak or quiet spot on the dial, the 19khz adjustment could be way off and read anywhere between 17khz to 21khz. Therefore, the proper and best way to do the adjustment is to tune to a "quiet" spot on the dial, then adjust to 19khz. This guarantees that your tuner will lock on strong as well as weak stations. Just a note, most service manuals want this adjusted to within +/-100hz (some +/- 50hz) to be considered adjusted to spec. That is a very fine adjustment that can't be obtained by feel and you will notice it on weaker stations.

If you've got a bunch of boomboxes in your collection, like lots of you do, you may find it worthwhile to invest in one. I've found that you can find them on the bay sometimes for quite reasonable.

baddboybill - 2009-03-22 20:32

I have never had a problem doing this, as a matter of fact I always get better reception right after I clean the tuner. Wink

superduper - 2009-03-22 21:52

Your mileage may vary. I'm glad you've had good experience but I've had enough not great experiences regarding cleaners that was either accidentally or deliberately introduced that I felt it appropriate to offer the caution statement. My caution specifically pertains to the variable capacitor only. Last time I had some cleaner accidentally work it's way onto the cap (2 months ago), it took almost a week for the AM to drift back where it could receive at all and a couple days for the FM to drift back to the appropriate location on the dial.

Here are some good tips from a very technical crowd regarding tuner cleaning:

Tuner Cleaning

baddboybill - 2009-03-22 22:44

Thanks for info Cool

hlr - 2009-03-22 22:52

To build a bit on what Stormin Normin said, if you don't have a frequency counter handy, a trick I've used with success to get things working reasonably well for the time being is this:
First, turn the pot back and forth a few times, then back to where it was. This will clean it a bit. Then find a good station and find the centermost of the range where it's stereo. This will ensure that it at least works. Finally, find a more distant station (and maybe store the antenna to worsen the reception) and experiment with finding a more exact setting where it'll lock on to stereo most consistently whenever you detune and then retune the station. You might try a few different weaker stations in order to be more thorough.