[Amps] Collins 30L-1 / 572's B

[R.Measures]

On Sep 19, 2004, at 7:25 PM, k7fm wrote:

> Rich said:
>
> "With 1700VDC on the anode, there would be virtually no advantage to 
> 572Bs
> for SSB."
>
> Well, maybe not if you have no problem with holes in the plate.  Many 
> years
> ago, before I realized that you should have about as much plate 
> dissipation
> as you have output to be safe, I burned a hole about the size of a 
> dime in
> an 811A.  The 572B is much more tolerant to normal abuse because of the
> superior plate construction.  Even normal tuneup can push the envelope 
> of
> the 811A.  No, you will not get any more output - but if the 572B 
> tubes are
> available they should last longer.

Colin -- 'Normal' tune-up for an 811A or a 4-65A is Not to use NØN 
(hammer-down) tune-up due to it's delicate anode.  A tuning pulser is a 
safer method of tune-up for SSB or CW.  Another method is a string of 
50wpm dits.  Also, the 30L-1 does not have a HV PS that maintains good 
V-regulation with NØN, so there would be a slight error with a 
hammer-down tune.
>
> Colin  K7FM
>
>
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Richard L. Measures, AG6K, 805.386.3734.  www.somis.org