MCI JH-110 Series Sync Relay

[Al_Huero]

I've got a dead sync relay on one of my channels in my machine. The original relay was made by Aromat with a number K4E24V-9. I've found replacements at few old component resellers on the web; but one quote I received was for $145 a pop. I'm waiting on a quote from the guys over at Blevins; but does anyone know of a currently manufactured replacement that would work?

[The Scum]

I think Aromat is now marketed as Panasonic.

Take some careful measurements, then leaf through the Digikey catalog to see if you can find a physical match. I'm almost certain that the "4e" means 4 pole, and the "24V" means a 24 Volt coil.

[Al_Huero]

Right on, thanks. My only question is whether it's running AC or DC; but I can check the schematic; and I sort of doubt there's a voltage transformer in there.

[CurtZHP]

I'm thinking 24V coil as well, because that's what the power supply puts out.

You could just find a generic 24V relay, tie wrap it to the chassis and run wires to it. Not pretty, but it's inside the machine. It's not like anyone will see it.

[The Scum]

Relays are the backbone of industrial electronics. They've got moving parts and they wear out, but there are reasons that can't be replaced with some other technology. I'd seriously doubt a relay that MCI used in the 70's is truly obsolete. The vendor may have changed hands 3 times, and renumbered their parts at each step, but the a nearly same part will be out there.

Seriously - the Panasonic stuff I saw at DK had numbers pretty darn close to the one mentioned.

As for AC vs DC - you could always actuate the one on the channel that's working, and measure the voltage present. Also, just because a coil is spec'd at a particular voltage, it doesn't mean that's what's switching it.

[Al_Huero]

Good info you guys, thanks.

[Al_Huero]

So, after some searching this is the closest match I can find at this point:

http://search.digikey.com/scripts/DkSea ... Z4-V700-ND

I got some more info off the Aromat relay:
24 VDC coil
Contacts rated 2A @ 28 VDC; 1A @ 125 VAC

The dimensions between the two relays match pretty well. The one thing I'm having trouble determining is whether the contacts/terminals are set up the same way and will interface with the existing socket properly. Here's a photo of the schematic off the existing relay. It's a bit hard to see, but if you can make out the way one set looks the are basically four equivalent ones.

[Nate Dort]

Page 4 of that datasheet has the wiring diagram for the new relay. Looks like the same layout and default state to me.

[Al_Huero]

Right on, thanks Nate!

[cjmnash]

i restore MCI machines and have thought i had a few bad sync (& record) relays in the past, but turns out a simple cleaning of the pins did the trick....never actually had a bad relay.

try that, hopefully it'll work for ya.

chris mara
www.nobraineraudio.com
www.welcometo1979.com

[Al_Huero]

Yeah, I've cleaned them like crazy without luck. I've had a couple more go bad switching back and forth from repro to cue mode. If I swap relays around between "good" and "bad" channels; the problem always follows the suspect relay. I'll try scrubbing on the terminals of the actual relays a bit more to see if that helps.