Trying a Hammond 158Q choke......NOT!

mightymike · Post by **mightymike** » Wed Nov 15, 2006 1:36 pm

Cost me 16 bucks and looks to have the right mount to fit George's chassis. "2.81 mount" I call it 2 and 7/8 light, but it's really 2 29/32".

How do these numbers look as far as the Ohms? Right spec for a Plexi?
I'm gonna find out soon.

It's 5 hy 150mA--105Ohm---400v---1.25lb---and has the right 2 7/8 light mount.

I almost got the 157Q which is 3.5 Hy---150mA--98 Ohm--400v---2 7/8"L mount as well.

The 159 Q which was 7Hy was too wide on the mount.

I'm still gonna get some Heyboers from George, but I allway heard good thing about Hammond forms Larry Rodgers and Chris ******.

robert · Post by **robert** » Wed Nov 15, 2006 1:39 pm

Hi mike,

beware of the choke's 400 Volt rating! I would go to 500V or higher, just for safety.

Regards

Robert

mightymike · Post by **mightymike** » Wed Nov 15, 2006 1:40 pm

shit!

The 159Q is 500v, but too wide. Crap

THanks for the heads up. I was able to cancel the order in time.

mightymike · Post by **mightymike** » Wed Nov 15, 2006 2:02 pm

Guess what,

I just got off the phone with someone at Heyboer (Phil?)
and he was reading off the spec of my Heyboer Choke part # HTS 7262, that's installed in my Aluminum 12000, and I just found out that it is:

5 Henry---150mA----105ohm---2 7/8 L mount

so far exact to the Hammond right?

wrong...

This thing is only rated for 250 Volts
It's been working fine in my 12000 for a long time.
But now you got me scared.

getting out my volt meter.

Now I'm curious what George's new Chokes are going to be rated for.
I think he said they were the same as my Heyboer, just different on the Varnish/finish.

robert · Post by **robert** » Wed Nov 15, 2006 2:31 pm

250Volts-

of course, they for shure would have a big safety margin, especially the Hammond chokes as a industrial product...

Let's wait what Larry recommends

Regards

Robert

mightymike · Post by **mightymike** » Wed Nov 15, 2006 2:38 pm

Hell and I thought the mA rating was what I needed to watch out for.
Chris ****** told me at least 150mA.

I'm putting a B string on, and as soon as I can, I gonna crank this on 10 and see what kinda voltage I'm getting at the choke dimed playing a low E power chord into feedback.

mightymike · Post by **mightymike** » Wed Nov 15, 2006 2:57 pm

Shit I'm at 430 duh.... How can that choke be 250v?

And I just shorted the Choke to the diode in the bias circuit when I pulled my clips away too fast. SOB.

Hope all I fried was that diode or a fuse.

I'm having a heck of a day today.

rockstah · Post by **rockstah** » Wed Nov 15, 2006 2:57 pm

mightymike wrote:Shit I'm at 430 duh.... How can that choke be 250v?

And I just shorted the Choke to the diode in the bias circuit when I pulled my clips away too fast. SOB.

Hope all I fried was that diode or a fuse.

I'm having a heck of a day today.

DOH!

mightymike · Post by **mightymike** » Wed Nov 15, 2006 3:04 pm

Well all I have to say is thank goodness for that fuse. (what's left of it

)

whew....Wipes forehead.

Maybe Phil was wrong. How can that Heyboer be a 250v choke, and still work in a 430v circuit, that goes up to 482v on the high taps.

I'm calling him back..

mightymike · Post by **mightymike** » Wed Nov 15, 2006 3:13 pm

Ok I just talked to Alden at Heyboer, Phil was gone for the day.
He said Phil must have calculated things wrong, because this choke should handle above 500v according to ALDEN, and it is for Marhalls, and they have been selling them for years.

So I'm safe, and you are totally correct Robert.

Thanks again, and I guess I'l just wait till George get's his new chokes and stop trying to think so much...

On a side note, I think I have the same choke in my JTm 45/100 with way over 500v.

And when I played the E Power chord on the 12000, the voltage goes down to the 390s, but as soon as I stop it goes back up to 430. I figured it would be the other way around.

Double Duh...

robert · Post by **robert** » Wed Nov 15, 2006 4:26 pm

Hi Mike,

good to hear that both you and your amp are allright!

The voltage rating is IMO a surprisingly often overseen fact- especially regarding wires and resistors.

I think, that we all should choose the "safe way" when we select the parts for our beautiful hobby.

Regards

Robert

novosibir · Post by **novosibir** » Wed Nov 15, 2006 4:57 pm

A choke rated for 250V might withstand the use with 500V even for years or decades, because they all have their safety margin with a factor between 1.5 and 2.5, but you don't have any guarantee for that.

Under bad circumstances (moisture, suddenly rain on the oper air stage, aso.) the core may spark to the (grounded) lams, what makes your guitar suddenly very very quite

Hopefully your amp is correctly grounded in this moment, otherwise you could say 'hello' to Petrus

Larry

mightymike · Post by **mightymike** » Wed Nov 15, 2006 7:01 pm

If it turned out the first guy was right at Heyboer, I would be ripping it out right now. 6 months or no 6 months.

Like you said it could last for decades, but I want it to be safe above all.
I don't like taking chances with safety.

novosibir · Post by **novosibir** » Wed Nov 15, 2006 7:15 pm

mightymike wrote:I don't like taking chances with safety.

I fully agree!

NEVER with safety!

Larry

mightymike · Post by **mightymike** » Thu Nov 16, 2006 9:02 am

If I was going to get one of the Hammonds, I think I would get a 600v rated one. That way I'm covered all the way up to JTM 45/100 @560v.

But that one is way bigger than 2 7/8 mount.