Marantz Model 150 Tuner "NULL" Adjustment..

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • Mark R
    Senior Member
    • Oct 2023
    • 71
    • USA
    #1

    Marantz Model 150 Tuner "NULL" Adjustment..

    I am not ashamed to say this is my first FM alignment I have ever done. I am well versed in electronics and repair. Been doing it for many years on Pro Audio Live sound equipment. Worked on Power amps EQ's musical gear and Large format Mixing Live consoles Etc. But now I can see this is a whole different world when it comes to tweaking this kind of gear. I do have the proper gear like the SENCORE SG 80 and HP Generators and Scopes Etc.

    Look below at Adjustment 12:8. The Null adjustment. I have a Heathkit IM-28 VTVM that was rebuilt and has new Burned in tubes that I used for this adjustment. It has a Center "0" Adjustment. The spec in 12:8 calls for "null reading (Zero Reading)at no signal On the DC 1 volt Range. So I grabbed pin #3 at the JA01 Board and it read up around 5.5 on the 1 volt scale from the Zero Mark on the left peg.

    I then turned the voltage down to "0" Volts or back to the left peg on the VTVM. What I am wondering is , should I have cranked the pointer on the VTVM up to to center "0", and then tried to "0" the pointer on the VTVM "0" center mark?
    I did the second part of the adjustment using the same left Zero mark. I understand the Term NULL... but to apply it here with this equipment and the way Marantz writes their Manuals is sometimes confusing. We all know that Marantz has made some errors' in their Manuals.

    So I'll leave it here and see what comes back. Click image for larger version Name: FM Alignment 150 Tuner.png Views: 354 Size: 120.9 KB ID: 3538288

    ​
    sigpichttps://www.badcaps.net/forum/image....ine=1697924519
    Tags: None
    Previous template Next

    Related Topics

    Collapse
    • Mark R
      Marantz Model 120 Tuner Craziness I am Stumped!
      by Mark R
      My Marantz 120 Tuner stopped receiving Stereo signals. It works fine other then Stereo. I have a fully loaded shop here with all test equipment except and RF signal Generator.

      I get great reception on FM so I have used that signal troubleshoot. I have been all over the MPX board and replaced all caps. Also the entire power supply caps were replaced.

      All Voltages on the MPX board are good... all Transistors Good...All Diodes Good and other components.

      The stereo lamp is good as I powered it up and it lights. The signal flow to that lamp is unbelievably...
      10-20-2023, 01:25 PM
    • DXseekerMO
      Samsung PN51F8500AFXZA broke off the tuner's F connector, can't get tuner de-soldered
      by DXseekerMO
      I can hear Fred Sanford now...."YOU BIG DUMMY".....I pulled the "F" connector out of the tuner by accident. The tuner number is BN40-00248B. Low and behold I had a scrap board with tuner number BN40-00248A. Although the tuner is different (according to Encompass.com) it's footprint on the board is exactly the same as the 248B so I decided to de-solder the tuner off the scrap board to see what I was getting in to.

      As you can see in the picture the terminals and solder pads are super small. No matter what I tried I could not get either the terminals or support...
      09-15-2021, 05:15 PM
    • BigOof
      Marantz SR5007 popping on volume change and mute in Direct Mode
      by BigOof
      Hi,

      I bought a used Marantz SR5007 and it's giving me some issues that I can't seem to really place. It functions well in most settings, ARC mostly works, it has no issues driving my speakers in any of the digital input modes, but I'm having issues running analog inputs in direct or pure direct mode. For some reason in this mode there's distortion for every volume increment I give it, but once the volume is stable it has no issues. Muting creates a loud pop, switching to another source also causes a pop and so does turning off the amp in that mode. Again, no issue in the digital modes....
      12-12-2024, 06:15 AM
    • oshimapt
      marantz sr6012 no sound
      by oshimapt
      hello guys,


      first of all i'm not a qualified repair guy, i am a diy guy and as years pass by i have some experience on repairing eletronics, and i'm hoping someone can share their experience.

      i have a marantz sr6012, some times it turns on and works normal, but after a while the sound cuts off or it starts getting distorted and then cuts off.

      when this happens there is no audio no matter the source used, and the OSD shows unknow audio signal from the source.


      i was reading very carefuly the service manual and it is all pointing for...
      10-17-2024, 09:49 AM
    • acedogblast
      Marantz SR5012 popping and other sound issues
      by acedogblast
      Hello I have a Marantz SR5012 7.1 AV receiver that is producing speaker pop and other sound issues. These sounds are coming out of all connected speakers regardless if they are configured to be used. The rca preouts are clean from these defects so I am assuming the problem has to be with the amplifier.
      These sound issues are random and unpredictable. There are times where the unit can go 10 minutes without any problems then suddenly the problems come back. It doesn't seem to matter if there is sound being played or not.

      I have disassembled the unit and was able to take out the...
      02-15-2023, 01:40 PM
    • Loading...
    • No more items.
    Working...