Discussion in 'Fisher' started by lopezluna, Oct 7, 2018.
Hi guys, I just aquired this fisher 200-c tuner and theres not much info on the net about it and was hoping that some of you fisher gurus can help me out with some information and let me know if this is any good and wich Fisher tuner this is comparable to. I picked up a Fisher kx-200 amp that I purchased thru the auction site and the seller had this tuner connected to the amp for me to audituon the amp. Well, I ended up buying the tuner too. The tuner is just dusty and will clean up nice. Any info on this tuner would be greatly appreciated, thanks in advance to you all. Ben
Not a lot of detail information I can provide except that the tuner circuits proper are still much the same as the FM-200B that preceded it. The big change is to the use of a SS MPX decoder in place of the old WX decoder sub-chassis that the previous model used. It looks like the FM Automatic stereo switching has gone SS as well, as maybe has the muting circuits. The Microtune circuit appears to be the same as that in its predecessor.
Thanks for the reply Dave. So do you think its a ok tuner or comparable to a 200b?
It is certainly comparable in terms of sensitivity and selectivity because the circuits that determine those specifications are basically identical between the two models. Being a Fisher, I'm sure the new SS MPX decoder is capable of performing equally good as well, but I have no personal experience with it to know for sure.
Thanks Dave. I feel better about having aquired it now. One channel volume way lower than the other. I tested all tubes all were good except for the 6bA6 tube location V9 on tuner has a short if my tester is correct. I ordered a 6BA6 tube and will test it when it arrives. Do you think its possibe that that tube is reason for low volume output on one channel? I have not opened up the tuner or cleaned up any of the pots yet.
No. Remember there will almost certainly be Channel A and B level controls on the rear of the unit by the audio outputs -- make sure they are both turned up equally. The two shielded tubes closest to the audio output jacks will be the final audio stages for both channels -- make sure those tubes are good as well.
Finally, if none of the above resolves the issue, then determine if the problem is present just in stereo mode, or in both stereo and mono mode. If the problem is present in both stereo and mono modes of operation, then the problem is almost surely associated with the audio output stages. If just in stereo mode, then the multiplex decoder will be the go-to target.
Of course, make sure all the tube sockets are clean, all tubes are lit up, etc. For whatever the reason, tuners seem to be plagued with more tube socket terminal and tube pin corrosion than any other piece of equipment I've seen -- and I mean to the point where the tubes won't light up. So while cleaning sockets, switches, and controls in amplifier equipment (when done) is invariably a measure to eradicate static or an occasional channel drop out, in tuners, it's sometimes needed just to get the darn thing to even work at all.
I will check and clean all that you mentioned above after work today. Thanks Dave
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