Re: Old '49 B-2 with scratchy sound and uneven notes
Scratchy keys and uneven volume is usually key contacts.Each key has 9 contacts under it. The contacts strike a busbar. There are then 9 busbars as well. There is a way to shift the busbar over slightly allowing the contacts to strike another spot. Looking in the back of the organ, to your right, (bass end) there is a large brass screw on the back of each manual. The upper manual had it located right behind the matching transformer so a little hard to see but easy to get to really. The lower manual is deeper into the cabinet and the brass screw located just below the same place the upper one is located.</p>
You want to get a long flat head screwdriver. Now, CANCEL ALL PRESETS!! I repeat, cancel all presets. This will mean no cantacts are touching the busbars. You do not want to shift any busbars with contacts touching them. It's not hard, I just want to make sure you CANCEL ALL PRESETS!</p>
Now, turn the upper busbar shifter screw counter clockwise a couple of turns. Try ther upper manual and see if it improves. It may require hitting the keys several times but hopefully you will get improvement. If so, repeat on the lower manual.</p>
If you get no improvement leave it there and continue to try it. If it gets worse, turn the screw back to where it was so be sure to count your turns.</p>
Normally, shifting improves the keying by allowing the contacts to strike a new area on the busbars.
</p>
Re: Old '49 B-2 with scratchy sound and uneven notes
I believe it is yes. There are basically two ways to shift busbars. The way I described earlier applies to B-3's, C-3's and their predecessors, as well as the M-series.</p>
I believe the T-series will work the way an L-series works. I don't have a T-series right here but if you look at the bass end of the manuals there should be a "tab" that is connected to the busbars that can move in and out, or left to right. On the L-series, the manuals are enclosed with wooden ends. There is a hole about the size of a nickel which has this tab inside. You can grab it with needle nose plyers and push and pull it. Moving it to a new location will give the contacts a new surface to strike.</p>
The T-series may have metal sides on the manuals like the E-series or H-series. Either way, there should be this tab there for shifting. Let me know if you find it.</p>
Re: Old '49 B-2 with scratchy sound and uneven notes
Will do. I'm waiting on some supplies from TW General. When they arrive, I'm going to pull the T away from the wall and get to work. I'll let you know how it goes.
Re: Old '49 B-2 with scratchy sound and uneven notes
Out of curiosity I looked for the busbar shifters on a T-422 I've got opened up at the moment and they are as George says. The upper manual is accessed from inside the back of the organ, lower manual from underneath in front of the organ.
Re: Old '49 B-2 with scratchy sound and uneven notes
[quote user="geoelectro"]
Scratchy keys and uneven volume is usually key contacts...turn the upper busbar shifter screw counter clockwise a couple of turns. Try ther upper manual and see if it improves. It may require hitting the keys several times but hopefully you will get improvement. If so, repeat on the lower manual.</p>
If you get no improvement leave it there and continue to try it. If it gets worse, turn the screw back to where it was so be sure to count your turns.</p>
Normally, shifting improves the keying by allowing the contacts to strike a new area on the busbars.
</p>
[/quote]</p>
thanks for the detailed instructions George and sorry to take so long to get back
</p>
here's a few photos to show you what I have - I can't tell which screw is which back there ...</p>
Re: Old '49 B-2 with scratchy sound and uneven notes
Looking in the back, there is a can looking device (matching transformer) located on the upper right side. It is fastened to the side of the case next to the preset panel. Right behind that can, is the backside of the upper manual. If you look under the can, at the upper manual, you should see a large brass screw. This is the busbar shifter. You will have to place your flathead screwdriver at an angle to reach this screw but it's not hard.</p>
Under that screw, deeper and under the upper manual, there is another screw just like it. This is for the lower manual. A long handle screwdriver will help here. Remember to cancel presets before turning the shifters. </p>
Re: Old '49 B-2 with scratchy sound and uneven notes
[quote user="geoelectro"]
Tell us... what was it?</p>
George
</p>
[/quote]</p>
</p>
I realized that you need to tap every key several times using one drawbar at a time. It was kind of tedious, but the organ not works without flaw. Mechanically, Hammond tonewheel organs must be one of the best designed products of all time! You just can't screw these things up![:D]
</p>
Scratchy keys and uneven volume is usually key contacts.Each key has 9 contacts under it. The contacts strike a busbar. There are then 9 busbars as well. There is a way to shift the busbar over slightly allowing the contacts to strike another spot. Looking in the back of the organ, to your right, (bass end) there is a large brass screw on the back of each manual. The upper manual had it located right behind the matching transformer so a little hard to see but easy to get to really. The lower manual is deeper into the cabinet and the brass screw located just below the same place the upper one is located.</p>
Now, turn the upper busbar shifter screw counter clockwise a couple of turns. Try ther upper manual and see if it improves. It may require hitting the keys several times but hopefully you will get improvement. If so, repeat on the lower manual.</p>
If you get no improvement leave it there and continue to try it. If it gets worse, turn the screw back to where it was so be sure to count your turns.</p>
Normally, shifting improves the keying by allowing the contacts to strike a new area on the busbars.
</p>
George</p>
thanks for that info, I tied it again today but it looks like the contacts are quite oxidized // ... I'll look around to see what the process for getting to the contact busses is like, etc ... ?
any advice is appreciated
---
ed. ... ok//
a busbar job ... reading further // thx for the info
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