[Amps] AL-811 & 572's

[Vic K2VCO]

150 ma. on the grid and 400 ma on the plate (due to power supply limitations). The 572B's 
absolute maximum rating is 275 ma per tube, but at the low plate voltage in that amp it 
probably isn't possible to obtain that anyway.

The absolute maximum grid current is 50 ma. both for the 811A and the 572B. So if the amp 
documentation specifies 150 ma for four tubes in RTTY, I would follow this recommendation.

The 572B has a greater plate dissipation than the 811A but requires a higher plate voltage 
to get more output.

The only advantage of replacing 811As with 572Bs is supposedly that they last longer due 
to the greater plate dissipation, but even that is controversial.

On 1/21/2011 9:50 AM, Thomas F. Giella NZ4O wrote:
> I have an AL-811 running 572B's instead of 811's. The manual says for RTTY
> mode to use a maximum of 150 ma on the grid and 400 ma on the plate for the
> 811's.
>
> What would be the maximum grid and plate current that I could use on the
> 572B's on RTTY?
>
> 73&  GUD DX,
> Thomas F. Giella, NZ4O
> Lakeland, FL, USA
> nz4o at tampabay.rr.com
>
> NZ4O Solar Space Weather And Geomagnetic Data Archive: http://www.nz4o.org
> NZ4O Daily LF/MF/HF/6M Radiowave Propagation Forecast:
> http://www.solarcycle24.org
>
>
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps

-- 
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/