[TenTec] Centaur Tubes odd ones in parallel

[Mike Schatzberg]

I've already done it. I've also tried the grid fuse as well. 

My SB 220 has the grids strapped like this. 

See Richard Measures pages pages on SB 220 mods. Seems to me he is the main advocate for this. 

This is nothing new, but if you want to see it work, stop by and I'll pull that amp with all of my mods from RF negative feedback to QSK out for you to play with. 

73,

Mike 
W2AJI 

Sent from my iPhone

> On Apr 1, 2015, at 11:59 PM, Rick - DJ0IP / NJ0IP <Rick at DJ0IP.de> wrote:
> 
> Mike,
> 
> Do you mean to unground the grounded grid and connect it through a resistor
> to ground?
> Hmmm, not sure about that.  Might work.
> Normally the 3-500z has two pins connected with big straps to ground (if I
> remember correctly).  
> This gives it some really solid grounding.
> Raising with a small resistor would enable controlling the current, but how
> good of quality of RF ground would it then be?
> 
> I'll tell you what.  You try it with your amp and let us know!  (hi)
> These tubes are now a couple hundred bucks a piece.
> 
> 73 - Rick, DJ0IP
> (Nr. Frankfurt am Main)
> 
> -----Original Message-----
> From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of Mike
> Schatzberg
> Sent: Wednesday, April 01, 2015 10:39 PM
> To: Discussion of Ten-Tec Equipment
> Subject: Re: [TenTec] Centaur Tubes odd ones in parallel
> 
> Why not equalize the grid current for each tube. Small resister to ground
> should do the trick. Some folks turn it into a grid fuse by using a very
> small wattage resister. If the grid current goes too high, they pop open. 
> 
> I've played with that concept, but I'm not a fan. 
> 
> 73,
> 
> Mike
> W2AJI 
> 
> Sent from my iPhone
> 
>> On Apr 1, 2015, at 2:06 PM, Rick - DJ0IP / NJ0IP <Rick at DJ0IP.de> wrote:
>> 
>> Mike, that's a good procedure.