[Amps] Weird tubes in an amplifier

[Carl]

I had a pair of VT-4C's, aka 211 Special, as a self excited oscillator on 80 
CW a few years ago, took me 2 1/2 years to confirm DXCC at about 100W out. 
The note sounded pretty good once I used regulated DC for filaments and 
plate. As a Class C PP amp figure on about 250W max for CW and 200W on AM.

The receivers were a couple of my early 1930's sets such as a SW-58, AGSX, 
FB-XA....not exactly high performance!

Carl
KM1H



----- Original Message ----- 
From: "Eddy Swynar" <deswynar at xplornet.ca>
To: <k7fm at teleport.com>
Cc: <amps at contesting.com>
Sent: Wednesday, January 29, 2014 11:51 AM
Subject: Re: [Amps] Weird tubes in an amplifier


>
> On 2014-01-29, at 12:15 AM, k7fm wrote:
>
>>
>> On 01/28/14 7:24 PM, Mark wrote:
>>> Just when I thought I had heard of almost every type of tube in an 
>>> amplifier, I talked to a ham that has 2 VT4C's in an older home brew 
>>> amplifier he has for sale.
>> The VT4C is aka the 211.  They have 100 watts of plate dissipation each. 
>> Filament is 10 volts at 3.25 amps.  Maximum frequency ratings of 15 MHz 
>> (whoops mc for that vintage).  They were often obtained surplus from the 
>> BC-375.
>>
>> My opinion is that they are a terrible tube for a linear amplifier. There 
>> are a number of triodes that can replace it, however these group of 
>> tubes have been bought up by audiophools, who think these triodes put out 
>> better notes than other amplifier devices.
>>
>> You can substitute a pair of 805 tubes, but they have also increased in 
>> price.  It might make a nice AM final amplifier, but may need some work 
>> for a linear.  You could trade out the tube sockets and filament 
>> transformer and use almost any triode.  Two 572B tubes would work
>>
>> In short, you can make it work on the low bands - but why?
>>
>> 73,  Colin  K7FM
>
>
>
> Hi Colin,
>
> Those 211 tubes are lusted-after by the vintage radio transmitting crowd, 
> too. A coupla years ago I built a 2x211 Colpitts self-excited transmitter 
> for use in one of the Antique Wireless Association events (i.e. "The 1929 
> QSO Party")...
>
> It sure did have a VERY unique note / tone, bar none...! And it was an 
> absolute blast to see those big ol' jugs light-up, too...
>
> ~73~ de Eddy VE3CUI - VE3XZ
>
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