Lowrey Holiday TLO Tuning.

[squidgelet10]

Hi again guys.
I have a slight tuning problem on this beast, although only a few notes are affected. I don't have a service manual, but have been told there are tuning pots on the back panel. There are indeed 12 can pots to be seen BUT, the question is: Can I safely assume that these tune the 12 chromatic notes of a scale which is then repeated/divided/multiplied down/up the the entire tonal range of the organ, ie one of them would control all the C's for example please?
Be good!
Cheers.
Mike C.

[indianajo]

Can potentiometers are typically about 1 cm high with a visible screwdriver slot in the top. Tuning capacitors typically have a screwdriver slot and a visible wedge shaped blade under the plastic cover.
Can tuning coils are typically 1-2" tall square cans with a hole and something down in there not necessarily near the top. Sometimes the slot is flat screwdriver, sometimes the slot is hex allen screw.
Your 12 cans are probably tuning inductors, They are a coil with a sintered iron slug in them to screw up and down and change the inductance. As sintered means made of powdered metal, the slugs are a bit fragile, and act differently with a steel tool touching them than if you touch them with brass or plastic. The slugs are also likely to be rusted and stuck.
Divider organs before top octave generator IC's (about 1974) have 12 oscillators and 12 tuning devices, and divide the top octave by 2 for each octave below the top one.
I would check the power supplies to see if they are nominal before I went buying tuning tools and risking breaking slugs if you have coils. Things don't work properly if the power supplies are way off, and the electrolytic caps in the power supplies are pretty well guarenteed to have decreased in value due to leakage of the water inside past the 20 or more year old rubber seal. These caps have a plus on one end, or after 1980 minus's in balls on a stripe, pointing at one lead. They are measured in microfarads, mf before 1980 and uf afterwards.
For a tuning reference, if your ear is not perfect, toy keyboards from the charity resale shop are portable. I use my H100 organ to tune my piano, but at 350 lb it is certainly not portable.

[Jan Girardot]

Hello, Squidge;

As a Lowrey tech of 55-years experience, a few words of advice. The TLO used 12 individual tuning coils, those silver cans across the back. DO NOT USE ANY KIND OF METAL SCREWDRIVER in tuning the slugs! Most Lowreys had a small plastic screwdriver in a clip inside the case. If not, pick up a set of alignment tools at Radio Shack. If you have a friend with a guitar tuner, you are in luck, as they are quite accurate and easy to use.

Good luck and let us know if you need further help,

. . . Jan
the OrganGrinder

[andyg]

Indie, OT. just curious to know how your piano sounds when tuned according to the 'mathematically correct' temperament of the H? Don't you find it slightly out of tune compared to what a piano should be, with its proper equal temperament, and probably 'stretched' tuning?

[squidgelet10]

Greetings each.
Thanks for all your helpful information. I did manage to download a service manual for the thing in the meantime, which gives me more information than I had before my original posting on here.
JAN: I didn't have any choices really as, after I had constructed a plastic tool for slot-head tuning slug, I discovered the poxy things are hex! Using a metal hex key doesn't appear to cause any problem after removal so tuning is quite easy really. I am just waiting to borrow an electronic tuner now as I am going to "tweak" all 12 while I am at it.
ANDREW: Unfortunately my esteemed colleague has both his tuners down at Beer for tuning their poxy Wurlitzer. You will no doubt already know about that heap of junk?
Stay good!
Cheers.
Mike C.