Reminder to check AC power wiring in older consoles

[David Anderson]

This is very basic Hammond information, but it bears repeating, especially for newer members, that you should check all AC lamp cord power wiring in Hammond consoles. This includes the lamp cord from the outlet box to the AC line panel and, in C cabinets, the lamp cord to the pedal lamp. The insulation can deteriorate and crack, leaving exposed conductors. Unplug the organ before checking since these wires are always live whenever the organ is plugged in.

You can replace it with standard brown or black 18/2 lamp cord.

I just saw an organ today sold by an "organ dealer" where the pedal lamp cord had exposed conductors that had not been replaced.

[geoffbrown]

Yes quite correct this something many people would overlook but an organ dealer has no excuse

[enor]

The brown type of internal mains wire with the slight ridges on the surface - those wires are particularly dangerous. They look perfectly ok to the eye at first glance, but try to bend them and they crack and crumble.

[David Anderson]

I don't think I've ever seen brown wire in a U.S. Hammond from the factory, only black.

[Grez A-100]

Great advice! Problem is, the people you are targeting (new Hammond owners) are the same people who might not understand your description of "AC Lamp cord power wiring." I know where the run motor power lamp is in my A100, and I can trace the (yellow) wire part of the way back toward the power amp, but I'm not 100 percent sure where else to look. Also, I'm not sure what the "outlet box" and the "AC line panel" is. Thanks. I'd be glad to mark up the photo below if you can give me more info.

http://www.hammondtoday.com/wp-conte...2/IMG_4768.jpg

[Drawbar Dave]

Fortunately it's already explained in the service manual!

[David Anderson]

As it happens, A-100s do not contain any of this wire. They don't have outlet boxes or pedal lamps.

The AC Line Panel is at the left end of the tone generator, looking from the back. It's the junction box for all the AC wiring.

[Goff]

The AC power cable (aka zip cord-lamp cord) is the black 2-conductor cable coming down out of the brown plastic tube (from the motors) going to the outlet box on the back of the B3.

After 50-60 years, needs replaced.
The black AC cable on this 1959 B3 was replaced in 2010 along with the rest of the wires seen in the loom above.

[gtc]

The original power cable on my 240 volt M-102 (1963) was rock hard and the insulation cracked off like shelling a peanut.

I replaced it with 3-core and grounded the power amp and will also run a ground wire to the reverb amp in due course.

[enor]

Don't forget the manual chassis and the tone generator!

[Alek Z]

This reminder certainly hasn't gone to waste! Hopefully it isn't too shameful to say I've owned a CV for 3 months and haven't thought to check the lamp cord... hehe, time for a little more work!

[gtc]

Don't forget the manual chassis and the tone generator!

Yes, I can do those, too. With my 240 volt S-6 I ran a ground wire to the metal knee-bar.

[muckelroy]

This reminder certainly hasn't gone to waste! Hopefully it isn't too shameful to say I've owned a CV for 3 months and haven't thought to check the lamp cord... hehe, time for a little more work!

My 1945 CV had surprisingly supple and thick round rubber sleeved lamp cord. It was probably still fine but I replaced it anyway. It also had a very well insulated and supple cloth + rubber outlet box run. Also, I probably could have kept using it but after 70 years I didn't want to throw the dice.

[David Anderson]

I think Hammond probably sourced lamp cord from a number of different suppliers. Some of it has held up just fine, and some of it is falling apart.

With the old outlet box wiring, the #1 failure in those is the red/black G-G wiring. It's run as a twisted pair separate from the other four wires, and the red & black insulation fails, causing the signal to short and disappear.

[Baldwin51]

might want to check your cables going to speakers, this is something I over looked for decades as my old c-3 has been through hell since 1955 and just kept going including two floods, now needs lots of work, when I turned it on yesterday one of my 4 tone cabinets went to roaring, so I started looking for a ground fault, I finally found the wires in the cable were rotten so I am replacing them, gonna take a good look at all the rest of the wires. as well. this organ has been a work horse for me since 1955 never had any real problems and one of the nicest sounding ones I ever heard. now needs a lot of work including recapping the tone generator. and rebuilding the Ao-28.

[WDH2]

This is an issue I'm seeing a lot of in the Washington, DC/Baltimore Md area. In August, following a particularly bad thunderstorm, I was called in by the pastor of a church which had taken a huge power surge when the transformer behind the church was struck. The resulting power surge fried nearly everything in the church, Circuit breaker panel, fire and burglar alarm and the C3/21H attached to it. the AO 28 after the surge.
I immediately replaced the preamp and began checking for any other problems. I touched the lamp cord power and the insulation crumbed in my hands. This surge even fried the Hamptons speed control in the Leslie.
Now I check all organs I service for this dry-rotted insulation on the power lines.
BTW, the same is true for the audio lines, some of them have crumbling insulation as well.
-WDH2

[tpappano]

Probably a good idea to also retrofit fuses to any old equipment you encounter that doesn't already have one, and use surge protectors, too. That was certainly a bad hit. I've had a couple surge protectors get blasted into another dimension from direct hits but the computers served by them were not damaged.

[theseacowexists]

What about old Leslie cables? Should those be retired at some point?

[David Anderson]

What about old Leslie cables? Should those be retired at some point?

Yes, they should be checked to make sure the insulation on the individual conductors is still in good condition. The wire used in Leslie cables came from various manufacturers over the years, and like all insulated wire, some of them had insulation that's still good, while others are turning brittle and failing. On some old cables, if you bend the cable, you can hear the insulation cracking inside the cable.

On very old Hammond Tone Cabinet cables, the outer jacket was black, and this material holds up very well; however, the wiring inside may be failing. The most common failure in older cables is a short of the G-G (red/black) wires that were run through the cable as a discrete twisted pair. The insulation on the red & black wires breaks down. I have seen a couple of cases where someone paralleled replacement G-G wires on the outside of a cable, securing it with electrical tape!

With organs that used lengths of 6-conductor cable between the preamp and outlet box like the CV, those cables should also be checked for insulation and G-G shorts. I saw one case where someone told a CV owner she needed a new preamp when, in reality, there was a G-G short between the preamp and outlet box.

[theseacowexists]

The most common failure in older cables is a short of the G-G (red/black) wires that were run through the cable as a discrete twisted pair.

Are the G-G wires twisted in Leslie cables, and is it necessary to have them twisted in a replacement cable?