Okay! From Carl and Dave's lips to God's ears, or is it the other way
around. The authorities have spoken and I now proceed with
confidence....
tnx
Rob
K5UJ
p.s. to the original poster--pse accept my appology for intruding on
the "voodoo" thread....I shall now step out of the way....
On Thu, Jul 15, 2010 at 3:00 PM, Carl <km1h@jeremy.mv.com> wrote:
> Agree with Dave. In the past I turned out many 1-2 holers grid or cathode
> driven to order; most covered 160 or 80-10M. Then I used 20-25W Globars or
> surplus 68 Ohm 50W Carborundums which I bought almost 100 in sealed packages
> for real cheap.
>
> Stopped that when all the local AM stations used the tubes until they were
> even almost dead as modulators or went SS. I did about 10 3CX3000A7's and a
> few 4CX5000A's after that.
>
> Carl
> KM1H
>
>
>
> ----- Original Message ----- From: "DAVE WHITE" <mausoptik@btinternet.com>
> To: <amps@contesting.com>; "Rob Atkinson" <ranchorobbo@gmail.com>
> Sent: Thursday, July 15, 2010 3:34 PM
> Subject: Re: [Amps] parasitic suppressor voodoo
>
>
> On a 2 times 4-1000A amp (5.5kv, grounded grid, cathode driven) I used two
> separate parasitic suppressors, each with 3 paralleled 50 ohm carbon
> resistors inside a 15mm diamater two-turn coil of 2mm copper wire over about
> 10mm length. The amp has worked flawlessly (80 thru 10m) for many years.
>
> If yours is a low band amp, you could probably make REALLY certain by
> increasing the number of turns on the coil. Initially with four turns the
> resistors smoked a little on 10m. I guessed "too much L". There was no
> science to building these suppressors - it was a case of looking at the
> W6SAI "Radio Handbook" and seeing if it worked. Voodoo? Maybe.
>
> I didn't try the amp without parasitic chokes but it seemed to work and "if
> it ain't broke, don't fix it"....
>
> Hope this helps
> Dave G0OIL
>
> --- On Thu, 15/7/10, Rob Atkinson <ranchorobbo@gmail.com> wrote:
>
> From: Rob Atkinson <ranchorobbo@gmail.com>
> Subject: Re: [Amps] parasitic suppressor voodoo
> To: amps@contesting.com
> Date: Thursday, 15 July, 2010, 18:40
>
> I would love to know what if any p.s. is needed on a pair 4-1000A at
> 4.5 KV triode connected cathode driven for 160, 75 and 40 m.
>
> rob
> K5UJ
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