[Amps] Advice

[k7rdx]

A single YC-156 if run at 6kv will make a pair of 8877`s look meek...And 
that`s with 100 watts drive...The 3CX3000A7 makes good suds too but requires 
about double the drive of the 156.Only drawbacks (IMO) of the 156 is 6+ 
minutes heater warm-up,and plate C limits high efficiency on the bands above 
20 meters..Also be prepared to invest serious $ for a capable HVPS.I just 
finished deck #4 since building the first in 2006 and still enjoy working 
with the 156..Pics availiable to anyone interested..Jim..K7RDX..
----- Original Message ----- 
From: "Carl" <km1h at jeremy.mv.com>
To: <dezrat1242 at yahoo.com>; "Roger" <sub1 at rogerhalstead.com>
Cc: <amps at contesting.com>
Sent: Thursday, December 03, 2009 2:22 PM
Subject: Re: [Amps] Advice


>I believe that goes way back to the "if one is good then 2 must be better
> phrase"
>
> Since a single ended 100TH, for example, couldnt make a KW on CW then 
> using
> a pair solved the problem. It actually goes mack to the original discovery
> of PP or parallel tubes sometime in the 20's or earlier.
>
> Its also a lot easier to run a pair of 8877's then stepping up to 3 kW + 
> Pd
> tube such as the 3CX3000A7 which is a drive and filament power hog. The 
> tube
> of choice then is the YC-156 which has its own issues.
>
> And for the cost involved 3 or 4 813's can make some serious RF. I use 4 
> in
> one of my AM amps.
>
> Carl
> KM1H
>
>
> ----- Original Message ----- 
> From: "Bill, W6WRT" <dezrat1242 at yahoo.com>
> To: "Roger" <sub1 at rogerhalstead.com>
> Cc: "Carl" <km1h at jeremy.mv.com>; <amps at contesting.com>
> Sent: Thursday, December 03, 2009 4:21 PM
> Subject: Re: [Amps] Advice
>
>
> ORIGINAL MESSAGE:
>
> On Wed, 02 Dec 2009 22:13:02 -0500, Roger <sub1 at rogerhalstead.com> wrote:
>
>>Tubes should always be used as a pair,
>>except for 813's and 572's and then you use 4 of them.
>
> REPLY:
>
> First time I've ever heard "tubes should be used as a pair". I have heard
> the
> opposite: "If you need more power, don't use two tubes, get a bigger 
> tube".
>
> Care to elaborate?
>
> 73, Bill W6WRT
>
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps


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