[Amps] 4K Ultra Restoration

Dave, K2DP k2dp at charter.net
Sun Dec 4 08:47:42 EST 2005


Bob,

We have one of these amps at our club station at work. If you do not have 
the manual for it, I can get you copy later this week. Don't know if it goes 
down to the PN of the blower fans. As for replacement parts, you might try 
contacting a company called "Radio Dan" at 
http://www.radiodan.com/index.html

He was the last of the Henry HF amplifier distributors/sales outlet before 
the Henry Company got out of the "tube" amplifier business. You might also 
contact Henry Radio directly and see what spare parts they have remaining in 
inventory. I would also suspect that either of those places could give you 
the proper part number for the fans.

73 and good luck with your amp. They need lots of TLC if they have been used 
heavily as the chain drive in the RF deck wears out and makes tuning a 
little more difficult.

Dave, K2DP, St. Louis
----- Original Message ----- 
From: "Bob Maser" <bmaser at tampabay.rr.com>
To: "AMPS" <amps at contesting.com>
Sent: Saturday, December 03, 2005 11:34 PM
Subject: [Amps] 4K Ultra Restoration


> Well, I found a 4K Ultra, brought it home, and started to clean up the 
> years
> of cigarette tar that this amp had been subjected to.  Not a pretty sight
> but fixable.  My first surprise was finding that some previous owner had
> replaced the original 240VAC blower with a pair of 115VAC muffin fans
> connected in series.  Does anyone out there have a blower that will fit?
> Can someone tell me what was the original blower used in the 4KU?  Looking
> at the Grainger catalog, it looks like the only one they sell that could
> possibly work is the Dayton 4C869, which is 230VAC @ 1600 RPM but I'm not
> sure of the opening size match.
>
> Also, I pulled out the 8877 and I believe it is the original.  It has what 
> I
> think is a date code printed on the top of the anode cap "7707" and I 
> assume
> that this is from the 7th week of 1977.  It may be older than the amp
> because the amp uses a ceramic 2000pf Jennings cap in C2, which I 
> understand
> was glass when the amp was first introduced in 1971 and later on they
> started using the more modern ceramic cap.  My amp does not have a serial
> number label so I don't know how old it really is.  I haven't gotten the 
> RF
> deck off the cabinet yet so I don't know how many surprises are under 
> there.
> The amp was operational when I first saw it about a month ago although it
> took about 100W to get 1500W out of it so I am going to have to replace 
> the
> 8877.  Anyone have one for sale at a reasonable price?  Ultimately I am
> planning on installing the new Eimac 3CX1500D7 but for now I just want to
> clean it up let it make RF.
>
> Help is appreciated,
> Bob Maser  W6TR
> Valrico, FL
>
>
>
>
> Bob
>
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