Does anyone have any further thoughts or comments on this? Is it OK to put the
amp into WSJT service at 400 watts?
73, Bill NZ5N
--- On Sat, 5/22/10, Bill Dzurilla <billdz.geo@yahoo.com> wrote:
> From: Bill Dzurilla <billdz.geo@yahoo.com>
> Subject: Re: How to read the 3-500Z spec sheet?
> To: amps@contesting.com
> Date: Saturday, May 22, 2010, 5:54 PM
> Thanks for the reply, but I don't
> think I follow.
>
> Guess I had interpreted the spec sheet as meaning that, if
> you configure the tube in class B grounded grid and apply HV
> of 2000v, you should expect to see 400ma of plate current
> and 500 watts of peak "useful" output.
>
> I am just trying to figure out if this homebrew amp, which
> does not have any manual or detailed info, is working as it
> should. If the spec sheet means what I think it means,
> it seems the amp is in the ballpark.
>
> 73, Bill NZ5N
> >Spec sheets don't know anything about load or no load.
> If it says for
> >example, 3000 volts at 500 mA, that's what it means.
>
> >73, Bill W6WRT
>
>
> --- On Sat, 5/22/10, Bill Dzurilla <billdz.geo@yahoo.com>
> wrote:
>
> > From: Bill Dzurilla <billdz.geo@yahoo.com>
> > Subject: How to read the 3-500Z spec sheet?
> > To: amps@contesting.com
> > Date: Saturday, May 22, 2010, 10:39 AM
> > Hi,
> >
> > I'm looking at the spec sheet for the 3-500Z at
> > http://www.scottbecker.net/tube/sheets/088/3/3-500Z.pdf
> >
> > At the top of the second pages, it gives numbers for
> > various parameters at different levels of high
> voltage
> > (3000, 2500, 2000, and 1500). Are these voltages at
> > load or no-load? And how do Single-Tone DC Plate
> > Current and Peak Envelope Useful Output Power
> correlate with
> > key down plate current and output?
> >
> > The reason I ask is because I picked up a homebrew 6m
> amp
> > with a single 3-500Z, which uses a power transformer
> from an
> > SB-200. Key down power output is 400w. Assuming
> > the amp's meters are accurate, no-load plate voltage
> is
> > 2300v, and plate voltage under full load is 1950v.
> > Plate current with no drive is 100ma and plate current
> with
> > full drive is .52a. About 40 watts of drive
> produces
> > the full 400w out. Further increases in drive, up
> to
> > 100w, do not increase output.
> >
> > Judging from the spec sheet's 2000v table, my guess is
> that
> > the amp is performing as well as it can with this
> power
> > supply. I know that a converted AL-80B with a
> single
> > 3-500Z can produce 900w or so on 6m, but it has a
> 3000v
> > p/s.
> >
> > Do you think it would be OK to run this amp at the
> full
> > 400w in WSJT (continuous carrier) modes?
> >
> > 73, Bill NZ5N
> >
> >
> >
> >
>
>
>
>
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|