[Amps] Ideal bandswitch brand for 3 kW out am?

[R L Measures]

A spark gap is much like a bi-directional transient-suppressor.   
There is no reason to use spherical conductors.  I make the gap screw- 
adjustable so that it can be calibrated with a high-potential  
tester.  Also, a sturdy 50 -500 ohm globar type resistor seems to  
help snub things during a glitch.  Setting the gap for about 2.2 x  
the anode supply voltage seems about right.  In most cases, this  
procedure will protect the Tune-C.

On Jun 30, 2006, at 8:51 AM, Larry Carman wrote:

> Concerning the calibrated spark gap: Is this consistent to what  
> I've seen in
> the Henry Plasma Gens? On the 3cx3000a7 RF gens they incorporated two
> aluminum half spheres with a small air gap between them. One of the  
> half
> spheres was connected to ground and the other to the tube anode.  
> What would
> be the formula to calculate the gap between the two? I'm sure it's  
> based on
> operation frequency, so this brings up another question. Would a  
> spark gap
> protect components on 160 as well as 10 meters??? Also, would this  
> protect
> the tune cap and bandswitch both? Would the load cap be protected  
> to any
> extent? I'm full of questions today.....
>
> Larry N5BIP
>
> -----Original Message-----
> From: amps-bounces at contesting.com [mailto:amps- 
> bounces at contesting.com] On
> Behalf Of R L Measures
> Sent: Friday, June 30, 2006 6:16 AM
> To: Tom W8JI
> Cc: amps at contesting.com
> Subject: Re: [Amps] Ideal bandswitch brand for 3 kW out am?
>
>
> On Jun 30, 2006, at 2:20 AM, Tom W8JI wrote:
>
>> We couldn't possibly know the ideal bandswitch anyway based
>> only on mode, frequency, and power.
>> There isn't enough information.
>>
> Good point.  As a rule of thumb, the bandswitch needs to have a
> comfortably higher BDV than that of the Tune-C, and the Tune-C needs
> to have a BDV slightly higher than the anode's DC supply. The idea
> here being that an arc at an air variable cap is no big deal, but an
> arc at a bandswitch is.   Also, vacuum-variable caps do not tolerate
> arcs well, so they need to be protected by an external, calibrated
> spark gap.
> .. end
>> 73 Tom
>>
>>
>> _______________________________________________
>> Amps mailing list
>> Amps at contesting.com
>> http://lists.contesting.com/mailman/listinfo/amps
>>
>
> R L MEASURES, AG6K. 805-386-3734
> r at somis.org
>
>
>
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>

R L MEASURES, AG6K. 805-386-3734
r at somis.org