[Amps] Updated amp pictures

[Carl]

> ORIGINAL MESSAGE:          (may be snipped)
>
> On Tue, 28 May 2013 17:15:33 -0700, you wrote:
>
>>Thanks. I'm not the best metalworker, and I'm no kind of an engineer, so 
>>my work doesn't
>>compare with that of some of the guys who regularly post here. But 
>>hopefully it will be of
>>interest.
>
> REPLY:
>
> Hi Vic:  I have three comments on the 4CX1000A amplifier which might be of
> use to you.
>
> 1. The load cap appears to be a standard broadcast band variable. If that 
> is
> so, it's voltage rating is right on the edge. As long as your SWR is 1:1 
> it
> will probably work, but much above that and you can expect some arcing at
> that power lever. Once an air variable arcs, small blisters form at the
> point of the arc and it becomes even more prone to arc. If you ever
> accidentally transmit into the wrong antenna, bye-bye load cap.
>
> 2. The plate choke is much too close to the tube's anode, IMO. I made this
> mistake once and eventually the choke burned. Even though there is only a
> few pF between the anode and the windings, at the extreme voltages 
> present,
> a lot of current can flow especially on the higher frequencies. You might
> get lucky and not have a problem, but watch for burned insulation on the
> turns nearest the anode. Not only that, but you are inadvertently setting 
> up
> a second parallel resonant circuit with that same capacitance and a 
> portion
> of the plate choke. Again, you might get lucky, but beware.
>
> 2. The band switch looks awfully small for a legal limit amp. A REAL legal
> limit bandswitch should be about four inches across and cost several 
> hundred
> dollars. One should not skimp here. Ask Carl how many undersized band
> switches he has replaced over the years.  :-)
>
> Otherwise, looks good. Having fun?
>
> 73, Bill W6WRT


I cant count that high! Mostly in Heath, Kenwood, Yaesu, low to mid range 
Ameritrons, some Dentrons, etc. using the standard Centralab and Oak 2.5" 
ceramic switch that in the Class C days was used at the 100W (400W PEP on AM 
at 100% modulation) level and then up to around 1200W in linears.

Carl
KM1H