Marantz 2385 tuner adjustment

[The Fuxtor]

Trying to set the dial accuracy and I cannot for the life of me locate the capacitor C123??

 

[bill_p]

C123 is on the main ganged tuning capacitor in the front end.

 

[The Fuxtor]

I cannot locate it on the actual unit??

 

[SoCal Sam]

FM Oscillator trimmer is usually at the end of the tuning gang.

 

[The Fuxtor]

The green circled adjustment seems more like a capacitor so I'm assuming it is C123?
But it leaves me without a L106. The component in red is a square red coil adjustment.It has no effect on the dial adjust

 

[The Fuxtor]

I'm guessing the cover needs to come off. Not very simple on this model.. sigh

 

[AE Bob]

I doubt you need to take the cover off. C123 is likely a small PCB mounted trimmer capacitor that looks similar to C257 and C258 in the photo. It is likely down on the PC board under the cover where you can get to it through one of the holes.

 

[The Fuxtor]

I doubt you need to take the cover off. C123 is likely a small PCB mounted trimmer capacitor that looks similar to C257 and C258 in the photo. It is likely down on the PC board under the cover where you can get to it through one of the holes.

I believe C123 is the trimmer on the far end circled in green on the pic.. looking underneath it is definitely a trimmer capacitor. But I'm missing the adjustment for the low end dial, those hex tool adjusters?

 

[The Fuxtor]

Ok. Here's a pic with cover removed. ( Another AK thread). Here we can see the transformer just left of the red fet. There are no other adjustments in here??

 

[bill_p]

Here is my best guess of the component designations. L106 seems to be adjusted by spreading or compressing the windings. C123 is not visible in the left photo. Nor is L101. If you follow the wiring maybe you can confirm some of the marked up designations I placed on the photo.

 

[rcs16]

Your component designations look correct.

 

[The Fuxtor]

Thanks guys. Very helpful!. Unfortunately the FM has totally gone dead?. I'm gonna start a new thread.

 

[The Fuxtor]

Here is my best guess of the component designations. L106 seems to be adjusted by spreading or compressing the windings. C123 is not visible in the left photo. Nor is L101. If you follow the wiring maybe you can confirm some of the marked up designations I placed on the photo.View attachment 3855983

I can spy the L106 inside but there is no access hole from the back to adjust it!!

 

[bill_p]

Before adjusting anything consider what might be causing the dial to be off. L106 is just a coil of wire, probably sealed with varnish or epoxy. Marantz didn't really intend for it to be adjusted once the receiver left the factory. Presumably the dial tracked within 200 kHz or so when the receiver was shipped.

If there is poor contact from the tuning capacitor gangs to the frame, things can be out of tune. See https://audiokarma.org/forums/threads/how-to-clean-a-tuner-analog.144163/ for how to clean up the relevant parts of the tuning capacitor. This should be done before adjusting things to see if it brings alignment back. There are cases here on the forum where cleaning the tuning capacitor did resolve dial tracking.

Another documented case involved the trimmer capacitor C123. Corrosion can ruin its performance and may require it to be replaced. This thread about the 2285B could well apply to your 2385. https://audiokarma.org/forums/threads/marantz-2285b-european-fm-alignment-help.935880/

Does tuning C123 shift the dial calibration at all? How far off is the dial now (where does a 90.1 station appear on the dial? How about a 107.1 station?)

 

[The Fuxtor]

I ended up pulling it out and adjusted it. Pain in the ass but I got it done.. took the better part of my afternoon.