[Amps] TL-922 and overdriving

[R.Measures]

On Dec 9, 2004, at 6:09 AM, k7fm wrote:

> "Hello,
> I recently changed my TRX for a TS-950SDX which has 150 W power 
> output. I'd
> like to know if it is dangerous to drive a TL-922 with 150 W, instead 
> of the
> recommended 100 W ?
> I ask that because I usually run 150 W and when  I turn on the 
> amplifier, I
> forgot to reduce power  sometimes...
> Maybe the best solution is to set the TRX max power to 100 W ?
> Regards
> Olivier"
>
> That depends.  First, I assume you have a callsign and this is not 
> about 11
> meters, because different rules apply there.
>
> It is most dangerous to do if you have neighbors, because they may 
> come over
> and choke you or shoot your cat.  Overdrive will cause serious 
> distortion
> and splatter - which is like bad breath except on 11 meters.  That 
> should be
> sufficient.
>
> If that is not enough, the grids of a pair 3-500 tubes are not rated to
> dissipate 150 watts, although doing so is not dangerous - it will 
> simply
> burn up the 3-500Z tubes.

My guess is that only c. 16% of the driving power for a g-g 3-500Z is 
dissipated by the grid.  //  RE:  burning up the grid:  Running a 
3-500Z's or /3-400Z's  grid red-hot will not burn it up.  (molybdneum 
melts at 2617ºC)
>
> If you use the power reduction control on the 950, that control may 
> not be
> effective until after the first spike, so you may save the grids but 
> still
> splatter.

The solution -except on 11m of course - is to back off the mic. gain 
control until barely any ALC is indicated.
>
> Best procedure is to use a scope to see what happens - or listen to the
> splatter created.
>
> Colin  K7FM
>
>
> ---
> Outgoing mail is certified Virus Free.
> Checked by AVG anti-virus system (http://www.grisoft.com).
> Version: 6.0.783 / Virus Database: 529 - Release Date: 10/25/04
>
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>

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