Marantz 2240 Alignment Discriminator L201

[Dave Sanders]

The alignment procedure for the Marantz 2240 specifies that the secondary core (upper) of the discriminator transformer (L201) be adjusted so that the tuning meter is at its center with no signal applied.

First question - since this module P200 where L201 is located is mounted under the main chassis and the adjustment hole is in the bottom module cover. What core is the secondary (upper); is it the one closest to the top of the chassis?

Second - what are the specs for this alignment tool? I have tried several different types and sizes and none of them seem to fit.

 

[dankik]

Any help here? (came up on 'similar threads')
https://audiokarma.org/forums/index.php?threads/coil-alignment-tools.914155/
https://audiokarma.org/forums/index.php?threads/marantz-2275-meter-centering-adjustment.742334/
one more,
https://audiokarma.org/forums/index.php?threads/2250-tuning-meter-adjustment.272891/

 

[Dave Sanders]

Thanks

 

[chazix]

What core is the secondary (upper); is it the one closest to the top of the chassis?

Caveat: I can't remember when I've worked on a 2240.

By convention, the upper core is the one accessed through the circular hole in the transformer case. The bottom core is the one accessed through a hole in the circuit board (if you're lucky enough that the manufacturer provided one).

I have to believe that the cores will be the smaller of the more-or-less standard core sizes that are hex-tool adjusted. The best tool I have found for those cores is here:

Tuning Tools | Coilcraft

www.coilcraft.com

 

[Dave Sanders]

In looking further at the access for the adjustment of L201 there are two places. The bottom as shown in the photo circled in RED. The top access is reached through the hole labeled FM-IFT2.
Thanks for lead on the tools.

 

[Dave Sanders]

I ordered a GC Electronics 18-530 Alignment Tool Kit and it contains the required tool.

 

[Oerets]

I wrap a small piece of medical white cloth tape around the shaft and make a fine line following length up down. (180* apart)
Using this along with two corresponding pencil marks on top of the metal cover when inserted the first time. To have a starting referance point for later if need be.