To the TenTec net
I recently bought a Centurion amp from my neighbor here in Cedaredge,
CO.this summer. I used it for about a month
when one day in a QSO it quit transmitting. I had the same situation as
the current case being discussed.
I finally gave up and sent it into TenTec as my time is limited being a
caregiver.
Well to make a long story short there was a cold solder joint in the
3-500 filament wiring around the tube socket area.
If I had a presence of mind I would have looked to see if the tubes were
lit.
Having built a home brew amp w/pair of 3-500Z amp 40 years ago (160M to
10) with vacuum relays, Vacuum variable
etc. I felt kind of embarrassed not to have checked the tubes to see if
they were lit.
BTW I love the amp working with the Orion II
73, Curt WØALC
On 10/24/2014 6:55 AM, Bob McGraw - K4TAX wrote:
When you lift the cover, there is a HV shorting bar that should short
the HV to ground. Notice I say SHOULD. Never take anything for
granted when working with any product that uses high voltage. Use a
screwdriver with a well insulated handle to short the Cap on the top
of the tubes to chassis.
If you've spoken with Gary then take his advice.
73
Bob, K4TAX
----- Original Message ----- From: "Richards" <jrichards@k8jhr.com>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Friday, October 24, 2014 7:29 AM
Subject: Re: [TenTec] Centurion is on the Fritz
Hi Rick -- Thank you for the suggestions.
1) Your diagnostics mirror those I received from Gary at TT and from
another qualified technician/repairman. Unfortunately, the amp
failed multiple diagnostics, and a conversation with Gary Green
confirms it requires a trip to TT HQ for a full debriefing.
2) Contrary to assumption, the amp failed right away. It failed
after just just few quick exchanges with my relay man in Texas, even
before the second check in. DARN !
3) Contrary to assertion, the amp has AMPLE ventilation. I don't
want anyone to get the impression it was boxed in. Perhaps you do not
recall our previous discussion on this, we worked this over pretty
well some time ago. The stand you mention has HUGE cut outs (larger
than the vents in the amp cabinet) and is open on the front and
back. I added a pair of 120 mm fans to move air around it. There is
a four inch clearance on one side, and 10 inch clearance on the
other, so there is no chance the amp overheated because it is
enclosed. It has better ventilation than if something were stacked
directly on or next to it. I am sure you just don't recall how hard
I worked to avoid boxing it in as it has been some time since then.
THANK YOU ALL FOR YOUR QUICK AND HELPFUL SUGGESTIONS - All of which
confirm it is, as Rick correctly states, outside my expertise. I
appreciate all the suggested diagnostics which could be done with a
closed cabinet as I am surely disqualified from doing anything
inside, especially when it is powered on.
MY ONLY REMAINING QUESTION IS... Is there anything inside that can
give me a jolt (like a capacitor that needs to be discharged) while I
remove the tubes for shipping ? I would hate to discover that by
surprise.
Thanks again... it all helped to confirm it requires a qualified
technician to fix.
Happy days.
-------------------------- JHR ---------------------------
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