[TenTec] Ten-Tec Centurion 422 , looking for a new Tuning Air Cap

[David Sturm]

Hola Bob,
Thx for the comeback and suggestions.
SWR is 1.3.1
I found this on RF Parts, do you think if will work?
https://www.rfparts.com/73-1100-49.html
*David-*
*HC5DX*


*http://carmenlaveranda.com <http://carmenlaveranda.com>*

*I follow the DX CODE of CONDUCT*

[image: http://nfarl.org/picts/nfarlLogoTransparentBackground_medium.gif]

*From Ecuador, at 8,300 (2,500m) feet in Altitude, a 60'(19m) tower is tall
enough I say!*
*Love getting QSL cards*
*Excellent Coffee here, drink some and stay awake for some great DX*

*"It is not the class of license the Amateur holds, but the class of the
Amateur that holds the license."*
*David-*


On Thu, Oct 15, 2020 at 9:33 AM Bob McGraw <rmcgraw at blomand.net> wrote:

> David:
>
> The buzz is the result of arcing between the plates of the capacitor.
> This typically is the result of the amplifier being too lightly loaded
> resulting in excessive RF voltage in the output network.   Or perhaps
> the SWR is high.   In either case, the voltage in the PA tank was
> excessively high resulting in the arc.   Grounding has nothing to do
> with the issue but all equipment should be bonded to a common point for
> safety reasons.
>
> You can remove the capacitor and disassemble it.  Then using a file,
> carefully file away the rough areas of the affected plates. Then finish
> smoothing them with fine steel wool.   The plates are very soft and can
> be damaged by excessive force.  I suggest laying each plate on a flat
> surface when you are working on it, applying a downward force.  Then
> reassemble and install the capacitor.
>
> I suggest you check your SWR on your antenna system.  Any value of 3:1
> or greater is not suitable for the amplifier.  Address and correct the
> antenna system.    Also when tuning the amplifier be sure to TUNE and
> LOAD the amplifier correctly always adjusting for maximum output.  Then
> reduce drive to the desired operating power, but DO NOT change any
> tuning or loading.
>
> 73
>
> Bob, K4TAX
>
> On 10/15/2020 6:32 AM, David Sturm wrote:
> > Good morning all,
> > I have an excellent condition Centurion that I purchased in 2015 from a
> Ham
> > in Marietta GA
> > ( NK9R) and he purchased it in 2001 from another ham and then sent it
> into
> > Ten-Tec for a QSK installation and a new fan.
> > The 422 has been working faultlessly for years until last week. I got a
> > buzzing sound of 20m. So I stopped using it. I got a similar buzzing
> sound
> > at 40m.
> > Nothing has changed, all grounding and bonding in place( I'm in Ecuador
> and
> > have been operating with the same coax, 4" copper flashing for a ground
> and
> > bonding)
> > I opened up the cover and found on the stationary plates and the rotor
> > plates small pitting and some small melting.
> > *What would cause this?*
> >
> > *I'm looking for an option on cleaning the plates. Can/should this be
> > done?( short term)*
> > *(Long term)Where can I purchase a Tuning Air Capacitor to replace this
> > one? I was trying to find the uf and voltage rating, but I can't seem to
> > find it in the manual? Looking in the wrong schematic.*
> > Any help would be appreciated.
> > Thx
> > *David-*
> > *HC5DX*
> >
> > *WB4OZM*
> >
> >
> > *http://carmenlaveranda.com <http://carmenlaveranda.com>*
> >
> > *I follow the DX CODE of CONDUCT*
> >
> > [image: http://nfarl.org/picts/nfarlLogoTransparentBackground_medium.gif
> ]
> >
> > *From Ecuador, at 8,300 (2,500m) feet in Altitude, a 60'(19m) tower is
> tall
> > enough I say!*
> > *Love getting QSL cards*
> > *Excellent Coffee here, drink some and stay awake for some great DX*
> >
> > *"It is not the class of license the Amateur holds, but the class of the
> > Amateur that holds the license."*
> > *David-*
> > _______________________________________________
> > TenTec mailing list
> > TenTec at contesting.com
> > http://lists.contesting.com/mailman/listinfo/tentec
> >
>
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