proper chimney # for the 4-400?

[N3DRB The Derb]

I am planning a pair of 4-400's ( might as well, I've got everything I need) but I do need to scrounge 2 chimneys. Whats the eimac P/N on them suckas?   

[The Slab Bacon]

At the power level that you'll be running them at, you prolly wont need chimleys.
just be sure to blow some air up through the bases to cool the pins.
Maybe also put a muffin fan to blow a little air accross the glass if you cant find chimleys.

I have never had a chimley on my 4x1 and it does get a little "red in the face". Never had any problems. (other than killing plate iron)

[N4LTA]

I have used Coleman lantern chimneys on 3-500z and they worked pretty well.

Pat
N4LTA

[N3DRB The Derb]

yeah, but ratting up a pair shouldn't be too much bother. I just need to know what to look for.  

BTW, I gotz 2 HR8 heat caps for the 4X1 the the fest, let me know if you want em an I'll bring. I'm gonna bring that cardwell back too I think you need it more than I do. I spent 10 whole dollars at the show including admission.

[WBear2GCR]

Derbobium,

Glass mayo jars... temper in oven (I am told... think the comment was made here on amfone) after cutting & finishing.

The method is standard bottle cutting... score, then nichrome wire around, heat - <tink>!

You can see some of that on my Henry amplifier page - link on QRZ, not from my homepage.
Or search my call, bear and Henry 2k should come up.

                 _-_-WBear2GCR

[W2PFY]

just be sure to blow some air up through the bases to cool the pins.
Maybe also put a muffin fan to blow a little air accross the glass if you cant find chimleys.

Dat's all they do on the Desk KW and it runs a KW don't you know

[N3DRB The Derb]

I found it - SK406. 

[WQ9E]

Tim,

Those are pretty expensive unless you find a deal on them.  Unless you are running the 4-400A's pretty hard you don't need to deal with the chimney and associated blower since a couple of fans will provide plenty of cooling for them.  Even if you run them at the "classic" AM input level you should only be dissipating about 1/3 of rated and the fans are generally going to be a lot quieter.

As PFY stated, Johnson just used fans in the Desk KW (and also the T-Bolt) and tube heating has never been a problem.  Their triode cousins do pretty well in the Heath 220 with a single fan.  Heath used a pretty interesting air setup in the KL-1 with an air pipe to cool the anode seal if you want to go for the unusual.  My Drake L-7 is fan cooled and although I have never run into a problem with it I do prefer the cooling system (chimneys and blower) on the L-4B.  I think Drake did a real mismatch on these, especially if you run AM.  The 4 line used a "linear friendly" controlled carrier system while the TR-7 uses full carrier AM and the matching linear really gets warm in a hurry. 

Given the market price of chimneys, test the blower you plan to use first for noise before you spend the big bucks on a pair of SK-406's.

Rodger WQ9E

[Mike/W8BAC]

Tim,

The 4-400's in the Collins 20V-3 and V-2 ran a kilowatt, modulated 100% 24/7 for years with no chimneys or fancy sub chassis mounting. They (the chimneys) are fancy but (I think) unneeded. I'll be home this weekend and hope to hear you on the Derb-O-Phone.

Mike

[N3DRB The Derb]

I'll be on provided I get the ant in the air. I worked on it today but I just cant get the end up high enough. Guy next door hasn't been home enough for me to ask him to shoot some lines over. I'll try again this morning.

eh crap. nohing but rain all day and it's raining now. 

[N3DRB The Derb]

welp, I found a single chimney for 10 bucks. Could not pass that up. Now just gotta find another.   

[K1JJ]

welp, I found a single chimney for 10 bucks. Could not pass that up. Now just gotta find another.   

Good going, Derb!

I wasn't gonna say anything to avoid a debate, but if you have a choice of using a chimney or not, I would always go with one. 

A chimney evenly distributes the cooling 360 degrees around the tube with no hot spots. You can actually run the blower at a lower speed (less noise) when using chimneys cuz of the even flow.  Plus it just looks cool...

Now that you're gonna use them, consider drilling twelve  3/8"-1/2" holes in a circle around the tube socket so that the chimney JUST covers them. This will increase the flow around the tube glass and still let ample air flow thru the base socket seal area.

BTW, I use chimneys in every one of my nightmares, 4-1000A's, 3-500Z's, etc...

Later, OM.

T

[N3DRB The Derb]

well, my grasp exceeds my reach. not only is da man gonna send me a chimney, he's gonna send me some 4-400 broadcast pulls as well.
 


That's a thang, right there.

Plus it just looks cool... 

thats right, these are facts. Looking cool is important. It marks you as a man of fashion and distinction who styles and profiles at will wherever he finds his bad self, with the hot chix orbiting around his planet of hot buttered Soul like moons around Jupiter. You Dig? 

[Opcom]

Tim,

Those are pretty expensive unless you find a deal on them.  Unless you are running the 4-400A's pretty hard you don't need to deal with the chimney and associated blower since a couple of fans will provide plenty of cooling for them.  Even if you run them at the "classic" AM input level you should only be dissipating about 1/3 of rated and the fans are generally going to be a lot quieter.

As PFY stated, Johnson just used fans in the Desk KW (and also the T-Bolt) and tube heating has never been a problem.  Their triode cousins do pretty well in the Heath 220 with a single fan.  Heath used a pretty interesting air setup in the KL-1 with an air pipe to cool the anode seal if you want to go for the unusual.  My Drake L-7 is fan cooled and although I have never run into a problem with it I do prefer the cooling system (chimneys and blower) on the L-4B.  I think Drake did a real mismatch on these, especially if you run AM.  The 4 line used a "linear friendly" controlled carrier system while the TR-7 uses full carrier AM and the matching linear really gets warm in a hurry. 

Given the market price of chimneys, test the blower you plan to use first for noise before you spend the big bucks on a pair of SK-406's.

Rodger WQ9E

NO CHIMNEAS - OH THE HORROR!