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Marantz Tuner alignment (Model 104)

Theoberheim

Theoberheim

Knobby | Knoisy | Knice
I just picked up a nice little Marantz Model 104 out of the woodwork. The unit is in decent condition and works very nice. However, the needle pointer is a bit off. For example, here in Portland Oregon, we have a classic rock station on 92.3 FM. When I dial the station in, the needle points to 94.5 or so.

The pointer can be re-aligned by sliding it up or down the string. However, the pointer is glued in place. I do not want to take any chances by cutting the string, nor do I want to break the needle on accident. Before I do anything stupid by not knowing, I thought I would seek advice from the forum. Any tips would be greatly appreciated.

Here is a photo:

DSCN0114.JPG
 
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You should not do that. There is an internal adjustment for this alignement. I have a Marantz model 104, and I will open it to point you in the good direction. I'll be back tomorow. Please wait!
 
ecluser: Thanks to your willingness to take a look. I will hold off before I do anything. If there was a way I could fix it conventionally, then I would rather do that.


Oerets: Thanks for the tip. I will removing the glue if all else fails.
 
Here is some adjustments that you can do on the model 104, without special test equipment:

Low band FM frequency adjust: tune a station of known frequency in the lower part of the dial and adjust the coil L103 (red plastic behind the tuning capacitor assembly) for best reception at the correct frequency on the dial. If you don't have a plastic tool, you can use a steel tool but you may need to insert/turn/retract the steel tool because the steel tool may perturb this adjustment.

High band FM frequency adjust: tune a station of known frequency in the higher part of the dial and adjust the pear shaped capacitor on top of the tuning capacitor assembly (the fifth capacitor from the pulley) for best reception at the correct frequency on the dial .

Repeat the two preceding adjustments until no further adjustment is necessary.

FM stereo reception: tune a station that you know is strong and you should receive in stereo, mono switch released (in stereo position). Adjust the trim pot R302 (the one with a blue plastic cap, close to the HA1156 IC) for stereo reception, in the middle of the range which gives stereo reception.

Low band AM frequency adjust: tune a station of known frequency in the lower part of the dial and adjust the coil L202 (single coil with red screw between the tuning capacitor assembly and the HA1151 IC) for best reception at the correct frequency on the dial .

High band AM frequency adjust: tune a station of known frequency in the higher part of the dial and adjust the second and fourth square shaped capacitors on top of the tuning capacitor assembly, starting from the pulley, for best reception at the correct frequency on the dial.

Repeat the two preceding adjustments until no further adjustment is necessary.
 
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I will be following this thread with great interest as I have a 105 that needs the same adjustment. I also have a 104 that needs the front glass replaced as it looks to have been near extreme heat and will have to have the same adjustments made as well. Great thread!
 
ecluser:

I tried your prescribed method. It worked like a champ. I was able to align my 104 perfectly. Now I do not have to break the strings or undo the glue etc. Thanks for letting us know. The only problem is, my father was watching me while I was fixing it. Of course he had to say, "Boy, I would love to own a Marantz some day." He had one when he got back from Vietnam. I think I will have to give it to him for Christmas.

I have one question from here. Does this method work for all classic Marantz units? I have a Marantz Model 4270 that needs an adjustment; however, before I go through the trouble to take aparty my system and pull it out of the wood case, I was wondering if the tuning section for classic marantz units are the same.

Cheers,
:thmbsp:

ecluser said:
Here is some adjustments that you can do on the model 104, without special test equipment:

Low band FM frequency adjust: tune a station of known frequency in the lower part of the dial and adjust the coil L103 (red plastic behind the tuning capacitor assembly) for best reception at the correct frequency on the dial. If you don't have a plastic tool, you can use a steel tool but you may need to insert/turn/retract the steel tool because the steel tool may perturb this adjustment.

High band FM frequency adjust: tune a station of known frequency in the higher part of the dial and adjust the pear shaped capacitor on top of the tuning capacitor assembly (the fifth capacitor from the pulley) for best reception at the correct frequency on the dial .

Repeat the two preceding adjustments until no further adjustment is necessary.

FM stereo reception: tune a station that you know is strong and you should receive in stereo, mono switch released (in stereo position). Adjust the trim pot R302 (the one with a blue plastic cap, close to the HA1156 IC) for stereo reception, in the middle of the range which gives stereo reception.

Low band AM frequency adjust: tune a station of known frequency in the lower part of the dial and adjust the coil L202 (single coil with red screw between the tuning capacitor assembly and the HA1151 IC) for best reception at the correct frequency on the dial .

High band AM frequency adjust: tune a station of known frequency in the higher part of the dial and adjust the second and fourth square shaped capacitors on top of the tuning capacitor assembly, starting from the pulley, for best reception at the correct frequency on the dial.

Repeat the two preceding adjustments until no further adjustment is necessary.
Click to expand...
 
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Theoberheim said:
I have one question from here. Does this method work for all classic Marantz units? I have a Marantz Model 4270 that needs an adjustment; however, before I go through the trouble to take aparty my system and pull it out of the wood case, I was wondering if the tuning section for classic marantz units are the same.
Click to expand...

Take care! The procedure to adjust the model 104 tuner is specific for this tuner, but I used the procedure for the 2220B (because they have similitudes in the circuits) and I had to adapt it for the model 104. For example, the coil L103 in the model 104 corresponds to coil L104 in the 2220B... The part identification is not the same for all marantz tuner sections.

For the 4270, I didn't investigated. Many service manuals are in the marantz database section. The tuner section in the 4270 may be identical to another tuner for wich the manual is available. Catrafter is in a better position to help because he knows them much better than me.

I have uploaded the schematic for the model 104 (a scan from my user manual) on the database and also on eserviceinfo.com

By curiosity, is your stereo light active now?
 
ecluser said:
By curiosity, is your stereo light active now?
Click to expand...

Ecluser, Thanks for the information. However, the stereo light is not active. I am going to replace all lights with the LED conversion. I will post photos when I finish that project.
 
i know this is an old thread but i just wanted to say that i thought it was well laid out - great insight i'll check to see if its a similar process for the 105b
 
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