Pete & others,
First, thanks for the info. I'm not looking to increase the voltage
over what it is (unless you mean the increase is from it not being
loaded down so far). In the High V position, mine runs at about 3.2 to
3.3 kV unloaded then drops to about 2.8 kV under load.
I run AM quite frequently (Rich mentioned RTTY) and tune the amp with
~100W drive, then back the drive down until the amp is running at about
500W DC input (always in CW mode, BTW). Seems to work quite well.
That's why I'm interested this...
Maybe I should go buy the "5kW SB-220"... :-)
Joe
--- Pete Smith <n4zr@contesting.com> wrote:
> At 06:50 AM 3/19/03 -0800, you wrote:
> >Since I run a '922, I have a question: The "quarter S-unit" isn't
> my
> >concern. But would the added cooling + heavy duty XFMR provide
> added
> >headroom? In other words, I know it won't affect the signal
> strength
> >much, but would it be cleaner since it could handle higher peaks
> >instead of flat-topping & splattering (given the same drive level)?
> >Also, which Peter Dahl XFMR would work? I looked at their website
> and
> >found nothing for the '922.
>
>
> I think I would be very leery of any transformer that provided more
> voltage
> than the stock unit, because you could never be sure which components
> in
> the tank circuit would be the weak link. Could be the tune capacitr,
> or it
> could be the bandswitch (ouch). I'm not sure you can run more
> current to
> the 3-500Zs than the TL-922 will support now, so the power gain would
> be
> illusory. If it was a heavier transformer with the same voltage
> output,
> I'm sure it would give you more headroom, but you might accomplish
> the
> improvement much more cheaply by adding cooling.
>
> More cooling air never hurts -- I put the Harbach fan on my SB-220,
> and
> added a separate muffin fan exhausting from inside the power supply
> compartment, and my amp now runs usefully cooler under contest
> conditions.
>
>
> 73, Pete N4ZR
> The World HF Contest Station Database was updated 23 Feb 03.
> Are you current? www.pvrc.org/wcsd/wcsdsearch.htm
>
>
>
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