[Amps] copper vs steel /SS /brass conductors in a HF tank circuit

[Robert Harmon]

Ray,

Good question.  
I would like more information on this too.  My meager understanding
is that copper or silver plated copper strap is preferable for HF tank circuits.
I took the liberty of changing the title of the thread for this subject.

Bob
K6UJ



On Mar 19, 2011, at 11:07 AM, Ray Benny wrote:

> Carl & Bob,
>  
> You both mentioned not using steel or stainless steel hardware. I've always known not to use steel and have used SS instead. I just did some work on my AL1200 amp recently and replaced most of the tank circuit hardware from steel to SS.
> 
> Can you all explain the difference between steel, SS and brass? I haven't heard of anyone giving a short analysis of the each. I think others would be interested.
>  
> Tnx,
>  
> Ray,
> N6VR
>  
>  
> On Fri, Mar 18, 2011 at 7:01 PM, Robert Harmon <k6uj at pacbell.net> wrote:
> Carl,
> 
> I hear what you are saying on higher voltage caps and yes it is cramped, I checked the available room
> and there really isn't any room for adding much larger caps.
> RF Parts has some ceramic doorknobs in stock that look suitable.  They are 2000pf at 7.5kv and they are about 7/8" in diameter. A pair of these conected in parallel would fit o.k.
> 
> No steel or stainless, I am thinking of using 3/8" wide copper strap for the doorknobs. I would love to find some
> silver plated strap like the plate strap is,  but maybe getting too carried away.
> 
> 
> Bob
> K6UJ
> 
> 
> 
> 
> 
> 
> 
> 
> 
> On Mar 18, 2011, at 1:42 PM, Carl wrote:
> 
> > I see no reason to go higher voltage in that amp. Similar B+ level products have been using the standard 5KV ceramic doorknob for many decades. The antenna safety chokes are there for a reason and if there is an antenna fault while transmitting saving the 8874's will be your major concern....always monitor the grid current.
> >
> > With Russian caps you first need to have the room which is already cramped, and metric brass or screws and washers....you arent going to use steel or stainless are you?
> >
> > Carl
> > KM1H
> >
> >
> > ----- Original Message ----- From: "Robert Harmon" <k6uj at pacbell.net>
> > To: <dezrat1242 at yahoo.com>
> > Cc: <amps at contesting.com>
> > Sent: Tuesday, March 15, 2011 2:47 PM
> > Subject: Re: [Amps] doorknob cap suppliers ?
> >
> >
> >>
> >> I see your point.  I'll see if I can find higher voltage caps
> >> that will fit O.K.
> >> I have been looking at the Russian caps on ebay,
> >> good prices.
> >>
> >> thanks Bill,
> >>
> >> Bob
> >> K6UJ
> >>
> >>
> >>
> >>
> >> On Mar 14, 2011, at 10:51 AM, Bill, W6WRT wrote:
> >>
> >>> ORIGINAL MESSAGE:
> >>>
> >>> On Sun, 13 Mar 2011 12:00:53 -0700, Robert Harmon <k6uj at pacbell.net>
> >>> wrote:
> >>>
> >>>> Yes that is what is in there, two 2000pf 6kv discs in parallel.
> >>>> I'm going through and upgrading caps in the amp,
> >>>
> >>> REPLY:
> >>>
> >>> For what it's worth - IMO, 6kV is a little bit marginal. If you ever
> >>> have an antenna fault while transmitting (broken wire, shorted coax,
> >>> whatever) the voltage across the cap can easily exceed 6kV. As long as
> >>> you're upgrading, why not put in a 12 or 15 kV cap? The cost is only a
> >>> little more and the peace of mind is priceless.
> >>>
> >>> I recommend the Russian doorknobs on eBay. Good stuff.
> >>>
> >>> 73, Bill W6WRT
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> >>
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