Marantz 2130 Alignment

SES

New Member
My 2130 stereo light not coming on (light bulb is ok), quartz lock only works on 2 or 3 stations, mute cuts out most stations even in min position.
I have the service manual. Alignment is confusing. (I read the posting on miss labelled ? parts) did the first part but when get to the discriminator alignment I need more help.
I have all necessary test equipment RF generator, Scope , Dual VTM, Distortion analyzer, etc.

Thanks

Joe
 
Hi Joe,

yeah Marantz documentation is poor, full of mistake, and missing information.
R206 provides DC bias to the base of Q202.
I think you are to measure DCV across C233 and adjust L206 for a DCV null.This is with no RF input signal, tuned to a noisy spot on the dial.
Are you still using a VTVM? "Dual VTM"

Hopefully Mike will chime in to confirm what I think, I am pretty sure he has done a few of these high end tuners before.

Good luck
Rick
 
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What are you using for an RF gen? From the symptoms I have to wonder if the only problem is alignment. Agree, Marantz alignment docs assume you already know how to do an alignment, they sometimes use terms that aren't quite right, and leave some things out. When they say adjust for minimum distortion, what they really mean is reduce the level until the signal is barely recognizable, then adjust for best amplitude and centered noise. In step 8 they mean use the THD meter. Usually you want a very quiet spot on the dial, and I find only certain times of the day are suitable. Usually when I can't work on it. Evening and night are awful, as there's aren't any quiet spots where nothing is "pulling" the circuitry. For no signal conditions it may help to short the antenna terminals.
 
On the scope to your get a stereo display when tuned and locked to a station? If just a diagonal line, then you are mono. If you are receiving stereo could just be a lamp driver issue. Dirty switches are a possibility. Have you done the VCO adjustment for 76Khz. Step 4.3.2? Muting adjustments? 4.4? Thing with the 2130.. Get the scope aligned first. When center is zero it can be used to adjust the discriminator. Using the multi-path you can align the front-end. When center tuned adjust for peak and flat line. Kind of sounds like poor sensitivity, VCO or muting adjustments. 2130 is probably not the best tuner to be learning on.
 
What are you using for an RF gen? From the symptoms I have to wonder if the only problem is alignment. Agree, Marantz alignment docs assume you already know how to do an alignment, they sometimes use terms that aren't quite right, and leave some things out. When they say adjust for minimum distortion, what they really mean is reduce the level until the signal is barely recognizable, then adjust for best amplitude and centered noise. In step 8 they mean use the THD meter. Usually you want a very quiet spot on the dial, and I find only certain times of the day are suitable. Usually when I can't work on it. Evening and night are awful, as there's aren't any quiet spots where nothing is "pulling" the circuitry. For no signal conditions it may help to short the antenna terminals.

Hi ConradH
I have a JungJin 1261 (10 Khz to 260 Mhz) Rf generator which is a copy of the Kenwood 5110. I have the ability to decrease signal with 1 dBm so I don't rely on radio stations for signal source. I directly insert signal trough a 100pF capacitor and coax cable
I have a Leader LDM 171 distortion meter.
 
On the scope to your get a stereo display when tuned and locked to a station? If just a diagonal line, then you are mono. If you are receiving stereo could just be a lamp driver issue. Dirty switches are a possibility. Have you done the VCO adjustment for 76Khz. Step 4.3.2? Muting adjustments? 4.4? Thing with the 2130.. Get the scope aligned first. When center is zero it can be used to adjust the discriminator. Using the multi-path you can align the front-end. When center tuned adjust for peak and flat line. Kind of sounds like poor sensitivity, VCO or muting adjustments. 2130 is probably not the best tuner to be learning on.
Hi,
I tried to get a station trough air. Your right I had a mono signal (one diagonal line). I will do all alignments just did not got past the discriminator adjustment as was to late at night. Start working on it this afternoon.
 
Well after 3 more hrs off nonsense to understand this manual. I did some of the scope display alignment, except the 8 cm deflection on a 5 cm diameter display. Basically I adjusted vertical and horizontal to the markings on the scope.
Then I tried to do 4.1.8. to 11. In this section the manual talks about adjusting 4 Coils L205,206,202,203. How about the other 8 on the board? Then a lot of nonsense.
Any body did this recently? I don't know if this illegal to ask here but I'm prepared to pay some one to have proper instructions written for the whole tuner.
I can't do further adjustments until I'm done this. The Quartz lock doesn't work right, OT9 base does go from 0 to 0.6 Vdc when touch the wheel but the collector is at 0 volts all the time. PS all good, within reasonable voltage readings.
Thanks for your time,

Joe
 
face it the manual is typical Marantz crap. So we have this discussion going here and in fmtuners. Like I said, I have never done this tuner and very few have either. MikeW may not want to divulge all the trade secrets, which I do not blame him for not, it is a lot of work to capture and you should have one on the bench as you figure things out.
hopefully someone in fmtuners can help.
Where in Canada are you located?
 
This is the general problem with FM tuner alignment. You need to understand what needs to be done and why, because every procedure I've ever seen is lacking in one way or another. There are also several ways to accomplish some steps and my guess is the factory did it one way, then wrote procedures for the outside world using some other way. I don't know the OPs level of expertise, so my suggestions may be too much or too little. Being easily available, I'd look at the service manuals for various Marantz receivers and tuners from the same period. They tend to do things the same way. The tuners are not entirely unique. It might even be useful to read some other manufacturers procedures. This is the educational phase. Even grab a copy of the manual for a Sencore SG-165 because it has a lot of useful general alignment info. Find out about coupling methods because most of the time you don't just hook the test equipment to the circuit. You need isolation caps and dummy antennas. Break the problem down into separate sections. As handy as the built-in scope may be, I'd do the alignment of each section in the traditional way, then address the scope by itself. The problem will be if some section has an actual fault. You have to know what's normal and expected, so you can raise a flag when the results don't jive with how things should work. What you want is to be able to say with certainty that a given section, IF, discriminator or whatever, is aligned and working correctly, so you can forget it and move on to the next. Prevents going around in circles. As for a better procedure, one would need the unit on the bench in front of them to rewrite it. I've done it for a couple, and it's harder than you think to get every detail recorded. If there are undocumented adjustments you need to determine what they are. Don't touch 'em until you know what they do. Could be traps or something else.
 
face it the manual is typical Marantz crap. So we have this discussion going here and in fmtuners. Like I said, I have never done this tuner and very few have either. MikeW may not want to divulge all the trade secrets, which I do not blame him for not, it is a lot of work to capture and you should have one on the bench as you figure things out.
hopefully someone in fmtuners can help.
Where in Canada are you located?

Edmonton, I done some tuner alignments in the past but this one just got me. Don't worry I wont touch anything until I know what I do. Thanks
 
This is the general problem with FM tuner alignment. You need to understand what needs to be done and why, because every procedure I've ever seen is lacking in one way or another. There are also several ways to accomplish some steps and my guess is the factory did it one way, then wrote procedures for the outside world using some other way. I don't know the OPs level of expertise, so my suggestions may be too much or too little. Being easily available, I'd look at the service manuals for various Marantz receivers and tuners from the same period. They tend to do things the same way. The tuners are not entirely unique. It might even be useful to read some other manufacturers procedures. This is the educational phase. Even grab a copy of the manual for a Sencore SG-165 because it has a lot of useful general alignment info. Find out about coupling methods because most of the time you don't just hook the test equipment to the circuit. You need isolation caps and dummy antennas. Break the problem down into separate sections. As handy as the built-in scope may be, I'd do the alignment of each section in the traditional way, then address the scope by itself. The problem will be if some section has an actual fault. You have to know what's normal and expected, so you can raise a flag when the results don't jive with how things should work. What you want is to be able to say with certainty that a given section, IF, discriminator or whatever, is aligned and working correctly, so you can forget it and move on to the next. Prevents going around in circles. As for a better procedure, one would need the unit on the bench in front of them to rewrite it. I've done it for a couple, and it's harder than you think to get every detail recorded. If there are undocumented adjustments you need to determine what they are. Don't touch 'em until you know what they do. Could be traps or something else.
Thanks for the good suggestion on comparing with other similar tuner alignment procedures.
 
Not a trade secret thing. Its a time thing. Trying to translate this shit so the layperson can understand is not all that easy.
Keep this simple. You are not getting stereo. You are satisfied that you have a good discriminator zero. Assuming you adjusted the 75Khz VCO and that is good. Next would be to look at and adjust the muting. If the muting is working correctly then signal strength is too low. Stereo threshold is a function of the muting circuit. A failures in muting circuits are common, a leaky transistor can cause a muting action. The tuner thinks the signal level low or off center tuned.
 
All good tips here, you have great advice from people that know what they are doing with alignment.
Here's what I would add -
1) For an analog tuned tuner, always verify front end sensitivity and channel center first. The easiest way to do this is by both listening to the test signal (1 kHz tone) and observing it on a scope. Turn down the RF level until you get noise (muting off), then tune the tuner slightly L and R to make sure you are centered on the channel. then turn up the RF amplitude until you are barely noise free in mono, stereo off. This should be a level about 2-3 uV into 75 ohms. If you can't get close to this, something is amiss - the front end needs cleaning, or alignment, or the detector is way off, or something is broken.
2) To do a quick check on the MPX section, you can directly inject a low level (10-100 mV rms MAX) 19 kHz test signal (through a cap) into the MPX chip composite input pin. If all is well, it should light the stereo light. This assumes there is no other pin that has switched the chip to "mono" mode. IF so, and tuner controls say it is in stereo mode, search the origin of the control pin, and why it's switched to mono.
just a few points...
 
Another member sent me a procedure developed by a gentlemen in Japan for the ST-8 (basically identical to the 2130 and ST-7). It's converted to english. I would clean the front end and decide what steps if any you need to take below.

Keep in mind that if you have a problem with the tuner that is not an alignment issue and you start to make adjustments your problems will likely get much worse. You need to decide is is broken or out of alignment?



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