Tnx.
Bob, K4TAX
Sent from my iPhone
>> On Oct 22, 2020, at 8:01 PM, Bob McGraw K4TAX <rmcgraw@blomand.net> wrote:
> I hope it gets posted to the site. I was notified it was held due to too
> many recipients.
>
> Bob, K4TAX
>
>
> Sent from my iPhone
>
>>> On Oct 22, 2020, at 7:51 PM, Matt Harper <mharper2240@gmail.com> wrote:
>>
>> Excellent. Thank you Bob. Much appreciated!
>>
>> I hope our paths cross again.
>>
>> All the best,
>>
>> Matt, K4KIU
>>
>>> On Thu, Oct 22, 2020 at 8:45 PM Bob McGraw K4TAX <rmcgraw@blomand.net>
>>> wrote:
>>> I’ve posted to the Tentec group. Factually, this is a small issue to
>>> resolve. I’ve applied my repair approach to AM broadcast transmitters as
>>> far back as 1960.
>>>
>>> The biggest issue is to figure out what caused the flash over and determine
>>> how to prevent this from occurring again. I also touched on that in my
>>> earlier response.
>>>
>>> Bob, K4TAX
>>>
>>>
>>> Sent from my iPhone
>>>
>>>>> On Oct 22, 2020, at 5:02 PM, Matt Harper <mharper2240@gmail.com> wrote:
>>>>
>>>
>>>> Hi Bob,
>>>>
>>>> Very helpful. Thank you.
>>>>
>>>> It's helpful that you've had good success with the repair process that you
>>>> described. Have you had any further communications with David on this
>>>> topic? That would be good to know since I'll be talking with David on
>>>> Tuesday for our regular sked, If you'd like to join us, you're very
>>>> welcome to do that.
>>>>
>>>> 73's and thanks again for sharing your knowledge on this topic. For the
>>>> record, I have a Ten-Tec Orion II and really like it. No problems with the
>>>> Orion whatsoever!
>>>>
>>>> Matt, K4KIU
>>>>
>>>> Matt Harper
>>>> (804) 399-3422
>>>> mharper2240@gmail.com
>>>>
>>>>
>>>>> On Thu, Oct 22, 2020 at 5:39 PM Bob McGraw K4TAX <rmcgraw@blomand.net>
>>>>> wrote:
>>>>> Matt et al:
>>>>>
>>>>> I doubt that Tentec would have a direct replacement. You might send an
>>>>> e-mail to SERVICE@Tentec.Com and ask for availability and price.
>>>>>
>>>>> From my take, the capacitor arced over thus resulting in burning one or
>>>>> two plates. From experience, they can be repaired using the method I
>>>>> earlier outlined. I've done it successfully several times. On my
>>>>> Centurion and other amps that use air dielectric variables.
>>>>>
>>>>> As to replacing it with an new one, there is no assurance that the same
>>>>> thing won't occur with a new one. After all, what caused it to happen
>>>>> in the first place? These things don't wear out. However, if they
>>>>> flash over, damage occurs and this damage can be repaired.
>>>>>
>>>>> Just my take and experience on the issue.
>>>>>
>>>>> 73
>>>>>
>>>>> Bob, K4TAX
>>>>>
>>>>>
>>>>>
>>>>> On 10/22/2020 12:15 PM, Matt Harper wrote:
>>>>>> Hi Jerry,
>>>>>>
>>>>>> Thank you for your research, message and overall help! All much
>>>>>> appreciated (along with the manual for the amplifier). After a number
>>>>>> of years of good service, it would seem like replacing the capacitor
>>>>>> would be the best solution, if possible. However, Bob’s excellent
>>>>>> suggested approach to repairing the current one may be the best and/or
>>>>>> only way to go.
>>>>>>
>>>>>> Thanks again!
>>>>>>
>>>>>> Matt, K4KIU
>>>>>>
>>>>>> On Thu, Oct 22, 2020 at 12:11 PM <ni4f@earthlink.net> wrote:
>>>>>>> Hi Matt. David posted a message to the Ten-tec reflector on 15 October
>>>>>>> posing the question to the reflector:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> > 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*
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> FIRST RESPONSE WAS FROM A TEN-TEC GERU K4KAX THE SAME DAY
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> > 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.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> THEN DAVID POSED ANOTHER MESSAGE AS FOLLOWS
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> 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*
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> DON’T KNOW IF BOB ANSWERED HIM OFF LINE OR NOT. I HAVE COPIED BOB
>>>>>>> K4TAX ON THIS EMAIL
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> 73, JERRY NI4F
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> From: Matt Harper <mharper2240@gmail.com>
>>>>>>> Sent: Thursday, October 22, 2020 11:04 AM
>>>>>>> To: ni4f@earthlink.net
>>>>>>> Cc: Barry Gold <n9bs@embarqmail.com>; Bobr1919@hotmail.com; Calvin
>>>>>>> <k1cal@bellsouth.net>; K8kas1@aol.com; bernsteinmarty@gmail.com;
>>>>>>> robertriley4180@att.net; voila1@optonline.net; w3frg1@gmail.com;
>>>>>>> w4vr@verizon.net; wc1t@arrl.net; wf8i@hotmail.com
>>>>>>> Subject: Request for Assistance
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Good Morning All,
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> My friend David, HC5DX near Cuenca, Ecuador is having a problem with
>>>>>>> his Ten-Tec Centurion amplifier. Here are the specifics from him that
>>>>>>> I copied from another email. This was from a noted he sent to Palstar.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> “My Ten-Tec Centurion Amplifier arced the other day on three Stator
>>>>>>> plates and 4 rotor plates.
>>>>>>>
>>>>>>> Do you sell the plates( if not would you know where I can purchase
>>>>>>> them?) or would you sell the entire capacitor?”
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Palstar either hasn’t replied or they can’t help him.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Do any of you know where he can get an exact replacement for this
>>>>>>> capacitor? After several COVID-related failed attempts to visit him, I
>>>>>>> have a trip planned to Cuenca on November 11. It too may get delayed,
>>>>>>> but it’s still on as of now. If I go then, I could take ithe part with
>>>>>>> me.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Any ideas you have would be appreciated!
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Thanks and 73’s,
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Matt, K4KIU
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>>
>>>>>>> Matt Harper
>>>>>>> (804) 399-3422
>>>>>>> mharper2240@gmail.com
>>>>>>>
>>>>>> --
>>>>>> Matt Harper
>>>>>> (804) 399-3422
>>>>>> mharper2240@gmail.com
>> --
>> Matt Harper
>> (804) 399-3422
>> mharper2240@gmail.com
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