I actually haven’t blogged about this beast on my website yet. Why? I don’t know!
I picked up this 1959 Hammond M3 (A4 body style) with a Rhythm II unit bolted to it in Waterloo late last year. That Rhythm II box is a little rare on these things.
A friend of a friend was looking for a home for it, or it was possibly going to the dump. NOOOO!!!!!!!!
He had inherited it from his grandmother, but had no interest in keeping it. Fair enough.
One look at the beauty and I knew it should not be destined for the dump! It was physically in amazing condition! Even the bench wasn’t that aged!
And my draw dropped when I heard the bench was supposed to go to an in-law. I paid for that to stay with the organ.
It’s kind of like removing a seat from a jet. Ya just can’t! It’s meant to be with the machine capt’n!
What was wrong with it? Besides the power cord crumbling, he mentioned that a service tech had mentioned that a tube was blown.
I figured, “OK, no problem. Tubes are easy to test, and power cords are easy to change.”
I pick up a new restoration project with the aid of my neighbours and friends.
The Hammond M3 sat in my dining room all winter waiting for me to give it some TLC. Today was the day. Let’s find out what I’ve gotten myself into this time.
Old Hammond organs are ‘tone-wheel’ organs. By old, we’re talking early 1970’s back to the 1930’s. There’s a spinning rod with tone wheels attached to it inside that pick ups work off of to generate tones. Look that up on the web along with Telharmonium if you want to study how tone-wheels generate sound. You also want to keep a constant pitch with those tone wheels, and Hammond had invented the machine to do it – Synchronous motors from his clock designs. Nowadays in North America, we take constant electrical power levels for granted. Back in the early days of electric power, it wasn’t so steady, and that would throw electric time clocks out of whack frequently. Hammond invented a motor that could isolate the power fluctuations from the clock speed and keep a more steady time. So, with these two technologies in the organs, a Hammond tonewheel organ keeps a steady A440!
SO, you’ll find two switches on the older tone wheel organs to get them running. One to start up the spinning of the tone-wheel spindle, like a car ignition switch, and the second to keep it spinning at a constant speed.
So, work with me through this. Run your analytical skills along with me as you go through this.
Initial symptoms:
1. Scanner start worked – check
2. Scanner start a little noisy – OK, more noisy than my other M3 at home – raised eyebrow
3. Push power switch after 8 second of scanner start, no continuing scanner sound – hmmm
4. Test output on keyboard – nothing from keyboard or foot pedals, just a quiet hum – hmmm
Diagnostics time:
1. OK, let’s pull out the Rhythm II unit – yep, that’s working – so the amp is working, not a tube issue there
2. Wiggle the tubes – no change to the keyboard output, but it’s bugging me why the tone wheel scanner didn’t continue to spin after starting it up.
3. Read online – keywords ‘Hammond M3 scanner stops when powering on’ – Details: Scanner powers up, but the synchronous motor has a resistor on the circuit, thereby less power to the scanner, and if not oiled, will stop because the synchronous motor does not have a lot of torque. If the bearings are not oiled, the motor can’t turn the scanner shaft.
4. Read online – keywords ‘Hammond M3 oiling instructions’ – 1/2 on the left most filler, 3/4 for the middle and right most filler cups. Holy crap, that’s a lot of oil! OK. Do it.
5. Notice a couple of other spots where there are foam pieces just over the scanner shaft. I dab oil on them too (just a dab!)
Test time:
1. Switch the scanner start circuit on… wow, still kind of noisy. Well, there appears to be a rail down the middle of the scanner area under those oil fillers. I shake the scanner slightly back and forth…. Voila! Quiet and happy!
2. I turn on the power switch. Voila! It lives! I test the keyboard and bass pedals. EVERYTHING WORKS BEAUTIFULLY!
3. Drawbars rather scratchy – out comes the fader remedy lubricant. Works like a charm now.
So, all that’s left is to change the power cord, which I’ve already acquired, and polish up the keyboard/body, and it will be put up for sale.
Poor old beauty almost met a sad fate on the count of lack of oiling to the tone wheel scanner bearings.
Folks, be kind to your old Hammond organs! Remember to oil them!
