Young technician seeking instruction

[Th'Rift]

My first organ was an Electone. I had it for awhile, didn't really interest me then so I gave it away. I got into Hammonds a couple of years ago when I found a 123xl someone was throwing out. It had an internal Leslie, and lots of little innards to screw around with and it was a blast, but unbeknownst to me at the time wasn't what I wanted. Soon I picked up a Piper, which I still have and love to make awful sounds with. Then I found my first tonewheel spinet. The T-524 introduced me to "The Sound" and I was hooked. It was in rough shape when I got it, so I learned how to care for it, changed its fuses, oiled it, checked the connections and got it back sounding awesome. But it's fragile transistor based amplifier and what not didnt last through a half baked chop. It was a bad idea built on lofty goals. So now it sits waiting for my skill to rise, but meanwhile I had acquired an L-112 in FANTASTIC condition and an L-122 for parts with a Leslie 125. Working with, upkeeping and modifying these organs has become my whole world. The time came for me to upgrade and I went looking for the elusive 147. I live in a small town but there is a piano/organ service company here, and upon visiting there I've made a friend out of the owner who quickly offered me a gig doing small repairs on Hammonds.

So here I am. I have no schooling in electronics, I have a lot of experience working on instruments, soldering, knowing what not to touch, reading schematics, and a knack for making the thing do what its supposed to do, but I really need some guidance, some contacts, and some helpful friends to help me find my way to becoming my areas only Hammond tech. I'm looking for online resources, knowledge, suggestions for where to learn and people to bounce ideas off of.

Really I'm looking for help starting out, ideas. Conversation. I've never done anything besides play gigs, and fix instruments and I love these organs with my whole being, this is my path. I'm a believer in things happening the way they're gonna, and it's all being laid out in front of me. We have thousands of Hammonds and no dedicated tech, only one real sales guy, and I'm the only one he's ever met who is interested in Hammond the way I am.

Anyway, I came here, the biggest resource for this kind of work, seeking friendship and guidance. Cheers to you.

Regards,
Mitch

[David Anderson]

I still have the Dawes Electrical Engineering textbooks my grandfather used in the 1920s and 1930s. All the basics of circuit analysis are still the same, plus, in older textbooks, you will still find discussions of vacuum tubes, which have not been taught in EE programs since the early 1970s. Dawes is only one example of older textbooks on the subject.

You start with Ohm's Law: Voltage = Current x Resistance. Once you understand Ohm's Law and all its permutations, you will have a solid foundation upon which to build.

Too many people want to start out by trying to repair or build things without understanding how they work, at which point they run into one frustrating roadblock after another, roadblocks that are non-existent to people who understand the underlying principles. We see people beating their heads against the wall in this forum all the time because they are disinclined to put in the time to learn the basics.

If you don't understand the general principles, each repair is only an isolated event. When you understand the theory, each repair fits into the framework of a greater overall comprehension of the field.

[Th'Rift]

Thank you for the literature tips David, I'll be sure to seek out old electronics texts. I am the classic example of the uneducated go getter, though I do research things carefully and usually do trial runs before I make irreversible changes. Not having the electronics background is definitely holding me back at the moment. I'll be spending a lot of time learning the basics of electronics and seeking out relevant texts. I'm also going to take classes for electronics.
Any other suggestions for literature?

[JJMcS]

Really I'm looking for help starting out, ideas. Conversation. I've never done anything besides play gigs, and fix instruments and I love these organs with my whole being, this is my path. I'm a believer in things happening the way they're gonna, and it's all being laid out in front of me. We have thousands of Hammonds and no dedicated tech, only one real sales guy, and I'm the only one he's ever met who is interested in Hammond the way I am.

Anyway, I came here, the biggest resource for this kind of work, seeking friendship and guidance. Cheers to you.

Regards,
Mitch

What you seek is here:

http://list.hamtech.org/listinfo.cgi...ch-hamtech.org

Good luck.

[David Anderson]

One classic is the RCA Radiotron Designer's Handbook, but it written for people who already understand the basics. Since I have the Dawes books, I've never reviewed other texts, but I presume that they weren't the only introductory electrical engineering texts out there in the 1930s - 1950s.

Randall Aiken has a lot of good material on the Aiken Amps website, but I still think it's better to start with a book where all the topics are laid out in sequence. He covers many specific applications of the basic concepts as they relate to guitar amps.

The reason that some of the older textbooks are good for doing this kind of work is that they talk about the devices we run into in older amps that were state of the art at the time, but are now obsolete. You're never going to see pentode vacuum tubes mentioned in a modern EE text or any discussion of why they were developed. Solid-state circuits don't really operate the same way. I have to switch gears mentally when doing SS work.

[Sweet Pete]

My thrift store Radiotron Designers Handbook,AARL,1947(Amateur Radio) has the tables,theories,equations,all the basics.
It explains in detail how to build a power supply,audio amp,transmitter etc,and has vacuum tube data and illustrations.
Like David said,a few days of theory will speed things up considerably.

It's like playing from a chart. I'll ask this; Do you perform the written music the same on a second take of that tune?
Although my sight reading is limited,I do see chord structure and I can still hear.
Intuition is what we develop once we master the theory! Or at least have a general understanding of ohm's law!

[Th'Rift]

I have found most of the literature you've suggested! The Dawes electrical engineering textbooks have actually been reprinted by Forgotten Books, in case anyone is looking for them they're available from amazon and there are hundreds more than just the dawes texts. I've also discovered that google is making efforts to digitize old textbooks and make them available for free online, which is an invaluable resource for the modern tech. A fellow on youtube that does hammond tech work (though not particularly well) suggested that I start gathering the Hammond restoration books for non-techs, has anyone had much experience with these books?

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I greatly appreciate the advice, thank you.