[Collins] 30L-1 vs 30S-1

[Glen Zook]

The 30L-1 definitely does NOT have 500-watts of plate dissipation!

The 811A is rated at 65-watts of plate dissipation and, having 4-tubes, the 30L-1 has a total plate dissipation of 260-watts!

Collins definitely pushed the envelope with the 811A.  Art Collins reportedly worked with RCA and their 811A tubes and got permission to push the tubes.  The rated input power for the 30L-1 on CW was 1000-watts NOT to exceed 30-seconds key down time.  The rated input power for the 30L-1 on SSB is also 1000-watts continuous service.  However, the FCC equivalent power rating for SSB is only 20% which makes the average plate dissipation somewhat lower than on CW.  As such, the continuous rating for SSB as opposed to 30-seconds maximum key down with a 50% duty cycle for CW.
 Glen, K9STH Technical Adviser CCA
website:  http://k9sth.net 


    On Thursday, December 10, 2015 4:34 PM, Dr. Gerald N. Johnson <geraldj at netins.net> wrote:
 

 

On 12/10/2015 3:24 PM, Jim Isbell, W5JAI wrote:
> What can the 30S do that the 30L cant?
> ______________________________________________________________
>
At least 1500 watts from the S1 with a KW of plate dissipation with a 
tube designed in the 1950s where a linear is often barely 50% efficient 
vs a tough KW pep input from the L1 with only 500 watts of plate 
dissipation in tubes designed in about 1937. Basically a conservative 
design vs a ham style living on the edge design in the 30L1. I noticed 
in the catalogs from the 60 when power was limited to 1 KW input, that 
both had the same ratings but the S1 showed low intermod values and the 
L1 didn't mention them. To acheive that conservative design the S1 does 
take up a lot more space. And I think the S1 can run RTTY at full power 
which could fry the L1 quickly.

73, Jerry, K0CQ, Technical Adviser to the Collins Radio Association.

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