Phonoland

I have recently acquired a Rockola 434 Concerta which according to the manual is supposed to have a.02 mfd 1400 V.D.C. capacitor soldered across the leads. It is missing but the remnants of the leads are still there. A previous owner has rigged it for free-play so the solenoid is energized all the time. It seems to work fine as is. My question is should I replace it? Does it's removal have something to do with allowing the free-play? I have the capacitor (and 4 more if anyone needs one.)

Usually a cap of that type located on a "coil" is there for noise suppression, only. I doubt it serves any other function-However, if my great, but not too long memory serves me, that "solenoid" is the Guardian built, INTERMITTENT duty, type. It should not have been modified for free play, as the solenoid is prone to overheating, and thus, catching fire !
Ron Rich

That's what I was afraid of. I also wish it wasn't modified. Now to figure out what was done. I assume some modification was done to the credit unit. I recently acquired the jukebox and have had the amp rebuilt and gone through the mechanism (cleaning, lube etc.) There are a lack of service tech's in this area that I can call to check it out unfortunately.

Unfortunately, also, there are "several ways" that they can be modified--almost always in the credit unit, by "messing" with,or removing, the subtract pawl, or the subtract relay can be "spun" so that it does not engage with the credit wheel on a subtract (credit) pulse. Ron Rich

I'm pretty sure they removed the subtract prawl. Im pretty sure that i found it in the bottom of the box while cleaning it. luckily I have an OCD habit of not throwing out small parts, screws etc. I'll get into it this weekend and see if that's the case. I'm going to replace the missing capacitor as well.

OK--please read the PM I sent you also--
Ron Rich

To follow up:
The subtract prawl and spring were removed to set it on free play. I replaced the prawl and spring and it's taking coins again and the buzz is gone. I also replaced the capacitor which was the original reason for this post. Thanks!

Thanks--but please post a response to questions to the forum, so all can (hopefully) learn something---
Ron Rich

When a coil is energized, then de-energized using contacts, arcing occurs. The capacitor reduces the arcing, and by doing so lengthens the contact life and carbon build up. Think of the points/coil/capacitor(condensor) on a vintage car. Without a condensor (capacitor), the points burn up quickly. That is why the capacitor is there. I guess the tech who did the free play figured the capacitor wasn't needed since the coil stayed energized all the time. Arcing causes noise. So as a side benefit, noise (hash) is reduced also.

eddie wrote:When a coil is energized, then de-energized using contacts, arcing occurs. The capacitor reduces the arcing, and by doing so lengthens the contact life and carbon build up. Think of the points/coil/capacitor(condensor) on a vintage car. Without a condensor (capacitor), the points burn up quickly. That is why the capacitor is there. I guess the tech who did the free play figured the capacitor wasn't needed since the coil stayed energized all the time. Arcing causes noise. So as a side benefit, noise (hash) is reduced also.

I think you are correct. After playing it for a while the thing got pretty buzzy. It was almost drowned out by the buzzing of the ballast in the upper display box that I replaced. The capacitor has been replaced and it's taking coins and working fine. Thanks!