The Organ Forum

My 62' L102 is in rough shape. I dismantled it and cleaned with contact cleaner and I think i made it worse! (Scratchy as hell).

I have a light-sensitive pedal removed from a later series L and was wondering how to hook it up.

Are the resitor/cap networks located on the fiber board at the end of the pedal assembly identical? Is it just a matter of finding a 6 or 12V source for the lightbulb? where is a good place to tap into this source? Is it as simple as splicing the grey wires (in from pre-amp / out to main amp)?

 Any help would be appreciated. Thanks!

You can try swapping them. There is only one source for the light bulb in exp. pedal. It is called filament voltage...

Jon 

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I hate jazz!

johnny b3:

My 62' L102 is in rough shape. [...]

I have a light-sensitive pedal removed from a later series L and was wondering how to hook it up.

--Wouldn't it be easier just to put in a new potentiometer, rather than convert to the LDR/bulb unit?  From what I understand, they switched to the light-sensitive unit because the pots would give out after long use.  But I imagine you could get by for some time with a new one, especially if you use a quality/heavy-duty replacement.  Just my $.02.  Good luck, TD

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"The Commander-in-Chief answers him while chasing a fly,
Saying, 'Death to all those who would whimper and cry';
And dropping a barbell he points to the sky,
Saying, "The sun's not yellow - it's chicken."
-Bob D.

I like your .02$... 

Any idea what type of pot is needed or will I have to remove the old one first and take it to a shop? 

Crap, I just looked at a PDF schematic I had on the L100, but it's the later model with the light-sensitive pedal.  Are you on the Hammond_Zone list?  If not, I can ask over there for you -- definitely somebody there will know the proper component value.  Or you could just pull it and see if they printed the value on the pot - seems like they never do though when you need it!  Or, if you have a meter you can get a pretty close fix on the value. -TD 

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"The Commander-in-Chief answers him while chasing a fly,
Saying, 'Death to all those who would whimper and cry';
And dropping a barbell he points to the sky,
Saying, "The sun's not yellow - it's chicken."
-Bob D.

Would be sweet if you could ask over at hammond zone for me. I guess there could be some preferred replacements.

Thanks Dude 

Why make your life difficult? Swap the pedals and forgot about potentiometers. It would include less soldering then replacing the pots. Take light bulb supply from filament voltage - pin 4 and 5 of one of the 6BQ5 tubes. Just solder in underneath and you have your job done. And plug those 2 white RCA plugs.

The pot is 250K, linear type, with 6 mm axis - value from the schematic.

Anything else?

Jon 

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I hate jazz!

Johnny, your L100 is here: http://captain-foldback.com/Hammond_sub/schematics/L100_early.gif
 

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I hate jazz!

Hi

You might find this interesting. The guy built a modified pedal.................

http://www1.tripnet.se/~flm/hammond/diff.htm

I found this when I was fiddling with my L122.

Cheers

Dave

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1960 Hammond RT3 & 1963 Leslie 122R
1966 Hammond L122
1968 Hammond T202
1975 Leslie 710
2007 Yamaha PSR S-900 Arranger Workstation

Thanks, but i find his instructions too vague. Seems like a cool idea though.

I think i'm going to try to swap the pedals.
 

So I swapped the pedals - got the 6.3v out of the filament pins.

However, the expression pedal behaves oddly. I slowly depress the pedal as I play and the volume gets louder as it should...but when the pedal hits the floor, the volume continues to rise for another few seconds. Its quite noticeable. Any ideas as to why this occurs?

 

Thanks