[Amps] 813 efficiency

[Carl]

The 4E27A seems to be an audiophool contender and getting pricey plus it is 
a HV, low current tube to be efficient.

Eimac uses the first character to signal number of elements starting after 
WW2.

Another sleeper is the PL-175, very few realize it is a plug in swap with a 
4-400A, and is often almost given away. I picked up a pair NIB on Fleabay 
for $25 not long ago. I added a NIB Eimac 175A to the TX tube collection for 
$10.

I also picked up a pair of NIB QB5/1750's from the same place for $20, those 
will be modulating a NOS 4PR1000A.

There are also several other seldom heard of NIB TX tubes in the collection 
that are simply a standard tube with a funny ID on it (-;

Carl
KM1H



----- Original Message ----- 
From: "Bill Fuqua" <wlfuqu00 at uky.edu>
To: <amps at contesting.com>
Sent: Monday, February 25, 2013 1:22 PM
Subject: Re: [Amps] 813 efficiency


>   One tube in the 813 class never mentioned that is real cheap because 
> practically very few
> amplifiers or transmitters used them is the 4E27A Pentode.
> It has 125 watts plate dissipation and fits into a 813 socket.
>    Anyone out there use one in grounded grid operation? Should be similar 
> to
> 813's I would guess.
>
> It just dawned on me the designation used in that tube series.
>
> 3B28 is a diode
> 2C40 is a triode
> 4D32 is tetrode
> 4E27A is pentode
> the letter is describes how many element it has Obviously there is not an
> A designation.
> Wonder who came up with that one. Don't see a pattern for the numbers.
>
> 73
> Bill wa4lav
>
>
> At 11:09 AM 2/23/2013 -0500, Carl wrote:
>>For about the same money there are still many 4-250A and 400A's available.
>>
>>Carl
>>KM1H
>>
>>
>>
>>>Hi Guys,
>>>
>>>It absolutely gobsmacks me how some guys in this hobby would rather 
>>>whip-out the ol' VISA card & spend literally HUNDREDS on power amplifier 
>>>tubes, when the lowly ol' 813---paired with some twins, of course!---will 
>>>do the job as well, and at an absolute FRACTION of the price...
>>>
>>>Sure the tube has high interelectrode capacitance, & has been around 
>>>since before WW2: but so what? It's nothing that a bit of 21st century 
>>>technology can't master...and who cares about age? After all, I myself am 
>>>60 years old here, & hardly consider my existence to be "redundant"! Hi 
>>>Hi
>>>
>>>~73~ de Eddy VE3CUI - VE3XZ
>>>_______________________________________________
>>>Amps mailing list
>>>Amps at contesting.com
>>>http://lists.contesting.com/mailman/listinfo/amps
>>>
>>>
>>>-----
>>>No virus found in this message.
>>>Checked by AVG - www.avg.com
>>>Version: 10.0.1430 / Virus Database: 2639/5625 - Release Date: 02/23/13
>>
>>_______________________________________________
>>Amps mailing list
>>Amps at contesting.com
>>http://lists.contesting.com/mailman/listinfo/amps
>
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1430 / Virus Database: 2641/5634 - Release Date: 02/26/13
>