Re: [Amps] Ten-Tec Centurion

[R.Measures <r@somis.org>]

On Nov 10, 2004, at 5:25 PM, k7fm wrote:

> Rich said:
>
> "RF sensed switching invariably results in the amplifier hot-switching
> because RF is already present when the relays in the amplifier begin to
> switch.  Hot-switching creates current transients and those in turn 
> ring the
> anode circuit's vhf resonant circuit formed by the Tune-C, the Anode-C 
> and
> the anode lead's L.  In my opinion, such ringing is the seed signal 
> that
> gets fed back by anode-cathode C and initiates a regenerative 
> condition."
>
> Rich, it appears your theory is not consistent with Tom's results.

Yea, verily.   Mr. Rauch asserts that, unlike Cu and Ag, the RF-R of 
Ni-Cr alloy conductors decreases as frequency increases.  Does this 
make sense to you. Colin?

>  Tom said
> that when the amplifier was rf sensing, it would never arc.  This does 
> not
> support your theory that the arcing is due to the rf sensing, does it?

RF must be in the amplifier to trigger the RF sensing which causes the 
relays to close.  How could RF not be on the NO relay contacts as they 
are closing and yet be on the RF sensing circuit that is energizing the 
relay coils?
> One theory would be that the rf sensing would delay the turn on point 
> of the
> amplifier until after the spike of the TS-850 subsided.
>
> I note from the facts presented that the antenna is resonant and swr is
> "reasonable".  I suspect a likely combination of the leading edge 
> spike and
> enough reactance on 160 meters to allow excess voltage buildup.  On the
> other bands, the amplifier is loaded better and the leading edge spike 
> alone
> will not cause the arc.

Agreed.  The fly in the ointment is that if 2, 3-500Zs are being driven 
with 140w, driving them 280w will not double the output.  During the 
parasitics debate, Mr. Rauch claimed that a spike over-driving a SB-220 
could produce tank circuit potentials of triple the DC PS voltage - 
which would be c. 8500V.  If this were true, the max peak output from a 
SB-220 would be c. 13,000w.	
>

Richard L. Measures, AG6K, 805.386.3734.  www.somis.org

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