Sansui 9090 tuner meter

[Samiam7364]

I recently purchased a Sansui 9090 in very good condition. The receiver has been sitting for a good amount of time and it needed a good cleaning but now it really looks amazing inside and out. The first time I turned the receiver on the power meters lit up but I had no dial lights. I did some research and found out that this is a common problem and perform a modification that was recommended and now the dial lights work the way they should. The one thing that I haven't been able to correct is the tuner meter will not go dead center. When the unit is in the axillary mode the meter stays off to the left out of the center. When I tune in FM stations it stays to the left even when the signal meter is reading 4 or above. I am receiving stereo broadcast because the stereo lights up and I can confirm that the stereo does work. This has been a perplexing problem because I would like for the receiver to be right. I feel it might have something to do with the voltages perhaps it's not receiving enough. I'm not a technician by any means and this is why I'm reaching out I would appreciate any help anyone could give me in this matter thank you so much for your time.

 

[I LIKE MUSIC]

If the meter does not return to center when the receiver is turned off, it is a mechanical issue with the meter.

It has been a long time since I was inside one of these, but some meter movements have adjustments to correct for the unpowered resting place of the pointer. These adjustments are located on the meter its self.

If the meter returns to center when the receive is turned off, that indicates an electrical issue. It could be anything from a minor misalignment to a component failure.

 

[Samiam7364]

I just checked to see if the meter lines up when the receiver is off and it does lineup. I haven't checked to see if there is an adjustment on the meter itself I don't recall seeing anything on the outside but perhaps on the inside there may be some how to adjust the meter I will look. Thank you for your reply.

 

[I LIKE MUSIC]

If the meter lines up with the power off, it is not a meter issue, it will be an electrical issue.

 

[Samiam7364]

I will check the voltage with a multimeter you wouldn't happen to know the correct voltage for the meter?

 

[LBPete]

Trimmer VR01 on the tuner board (F-2549) adjusts that meter. It should be identified on the the board. If you can't adjust it with that trimmer, the board has a circuit or alignment problem.

As far as the modification you did to the lights, that mod bypasses the correct function of the lights. Originally the dial lights turn off when in aux, phono or tape and are only on in AM or FM modes. Many times you can get them working correctly by through cleaning of the function switich.



- Pete

 

[I LIKE MUSIC]

The FM detector could also be slightly out of tune. The ferrite material that is used along with the capacitors can and does age, although rather slowly, resulting in a change in tuning.

If the FM section of the receiver works and sounds good otherwise, adjusting VR01 will take care of the symptom even is the FM detector is slightly out of adjustment. It is likely that one might not hear the difference in any event.

 

[Samiam7364]

T thank you so

Trimmer VR01 on the tuner board (F-2549) adjusts that meter. It should be identified on the the board. If you can't adjust it with that trimmer, the board has a circuit or alignment problem.

As far as the modification you did to the lights, that mod bypasses the correct function of the lights. Originally the dial lights turn off when in aux, phono or tape and are only on in AM or FM modes. Many times you can get them working correctly by through cleaning of the function switich.



- Pete

Pete Thank You so much for your help what you suggested worked great! I adjusted the trimmer VR01 and I now have the tuner needle lined up dead center. As far as the modification goes I tried deox on the selector switch and still no go on those lights. Am I causing any harm to the receiver if I keep the modification intact? You are the best I so appreciate your advice.

 

[Samiam7364]

The FM detector could also be slightly out of tune. The ferrite material that is used along with the capacitors can and does age, although rather slowly, resulting in a change in tuning.

If the FM section of the receiver works and sounds good otherwise, adjusting VR01 will take care of the symptom even is the FM detector is slightly out of adjustment. It is likely that one might not hear the difference in any event.

Thank you for your time in response to my question. I am saving up for a full restoration that I'm sure we'll correct any aging issues that the receiver is having. It does however sound fantastic. I was just comparing it with my Pioneer SX 1010 that has been recapped. The Pioneer has a slightly warmer tonality where as the Sansui excels with the mid-range and straight-up power. It's a toss-up between tuners but I would give the edge to the Pioneer in the phono department probably because of the recap. Can you recommend anyone who does Sansui 9090 Restorations?

 

[LBPete]

Glad to help. The dial light mod simply bypasses the function switch. It won't harm anything. Sansui dropped the dial light feature on the successor to the 9090, the 9090DB. What "DeOxit" product did you use? Caig Labs, tags DeOxit on to almost all it's products. It may take a stronger solvent to clean that function switch. Try a good quality contact cleaner followed by DeOxit G5.

If you haven't already done so, please post the serial number in the Database thread. Click on the link in my signature block.

- Pete

 

[zebulon1]

The tune center meter has two opposing springs that keep it centered. If its off center when the set is off then it is broken as "I like music" mentioned.
The FM board applies +-mV's to center meter as the stations are tuned. once the separation is good the center reading on the meter is 0 (zero) volts. to the left is (-) mV's and the right is (+) mV's.
You can connect the DMM probes to the meter set to mV's DC and watch the DMM as you tune the stations.
The only way to really get a good bead on adjusting it is with a Sencore SG-165 or some such device.
This would guarantee the settings are correct before adjusting the meter.

 

[Samiam7364]

The tune center meter has two opposing springs that keep it centered. If its off center when the set is off then it is broken as "I like music" mentioned.
The FM board applies +-mV's to center meter as the stations are tuned. once the separation is good the center reading on the meter is 0 (zero) volts. to the left is (-) mV's and the right is (+) mV's.
You can connect the DMM probes to the meter set to mV's DC and watch the DMM as you tune the stations.
The only way to really get a good bead on adjusting it is with a Sencore SG-165 or some such device.
This would guarantee the settings are correct before adjusting the meter.

Thank you for your feedback the meter does go dead center when the receiver is off.