Al,
Unfortunately 2016 is not 1999.
It's tough to find good tubes anymore.
A few years ago, RF-Parts stopped the sales of 572B entirely until they
could work with their Chinese supplier and get the quality up to snuff.
They refused to sell an inferior product.
On their web site, RF-Parts writes "The Taylor Select 811A is the best
quality tube in current production." Obviously they mean best quality 811A.
The cost of a matched set of 3 is currently $95.85.
572B's are scarce. They are available in very limited quantities with a
matched set of 3 costing $239.85. More than twice the price of 811A.
It seems there is a waiting list.
See: https://www.rfparts.com/572b-tubes
73 - Rick, DJ0IP
(Nr. Frankfurt, Germany)
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Al Sirois
Sent: Thursday, February 04, 2016 6:53 PM
To: km2km@twc.com; tentec@contesting.com
Cc: Ron Sirois; k8mp@aol.com
Subject: Re: [TenTec] Model 411 amp (aka Centaur)
TUBES..........My T-T Manual says to use 811-A, not 572-B.....>
I bought matched tubes from RF Parts in 1999 and they are still in the amp
and working fine. I got 450 W out of them this morning on 80 meters.
I do have spare 572-B's, but they are for my back-up amp a FL-2100-B.
I've never swopped the tubes between the two amps..... I probably don't want
to.
Good Luck with you guys in this discussion group.
N1MHC@arrl.net
Al Sirois
East Boothbay, ME 04544-0002
==========================
-----Original Message-----
From: Joe Papworth via TenTec
Sent: Thursday, January 28, 2016 9:54 AM
To: km2km@twc.com ; tentec@contesting.com
Cc: k8mp@aol.com
Subject: Re: [TenTec] Model 411 amp (aka Centaur)
Thanks Kris,
If I was desperate, I'd run it on two tubes.?
BTW- I haven't bit the bullet on a new tubes yet cuz from what I read on the
net, the ones on the market now just plain suck.
Seeeeeeeeeeeeya, Joe
-----Original Message-----
From: km2km <km2km@twc.com>
To: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Cc: k8mp <k8mp@aol.com>
Sent: Thu, Jan 28, 2016 9:45 am
Subject: Re: [TenTec] Model 411 amp (aka Centaur)
Good morning Joe,
Yes, my AMP does make a "thunk" when turned on, but, for example, I have
been
using it for an hour. Then I turned it off. Now, 15 minutes later, I turn
it
on and it does not "Thunk".
I found that this AMP was built well, and the only issues for over 20 years
have
been the tubes, and of of the toggle switches (IP/EP). The change to 10
meters
was a snap.
Yes, it could have a quieter fan, but it is a good AMP and makes an S-unit
difference.
Good luck with the tubes. BTW I have used it with only two tubes, while
waiting for a new set.
Kris
Kris KM2KM
MERSCHROD
123 Warren Road
Ithaca, NY 14850
---- Joe Papworth via TenTec <tentec@contesting.com> wrote:
=============
Hi Kris,
Thanks for the info.
It sounds like that store proprietor had gone a few rounds with some rigs.
Hi hi
I'll try the tubes by adding one at a time tomorrow.
Say, does your Centaur make a loud in-rush clunk when you fire it up?
And where did you buy your matched set?
Later, Joe, K8MP
Sent from AOL Mobile Mail
-----Original Message-----
From: km2km <km2km@twc.com>
To: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Sent: Tue, Jan 26, 2016 06:28 PM
Subject: Re: [TenTec] Model 411 amp (aka Centaur)
I'm late chiming in. My problem with the fuses has always been a shorted
tube.
You are on the right track. Test one fuse at a time, or start with one,
add
another, then the third. BTW a matched set is better than an unmatched set
HOWEVER, I had three misc tubes gathered over the years and put them in and
do
pretty well with them. I did that while waiting for a new matched set. Now
the
matched set is on the shelf waiting their turn!!!
The guy at the local electronics store said to me one day when I bought a
dozen
fuses, "You do know that if you don't fix it then it will still blow fuses!"
good luck,
Kris
Kris KM2KM
MERSCHROD
123 Warren Road
Ithaca, NY 14850
---- Joe Papworth via TenTec <<a
href='tentec@contesting.com?'mailto:tentec@contesting.com'>tentec@contest
ing.com>
wrote:
=============
It has stayed on with the tubes removed for a while.?
I'm examining/ohming the tubes now.
-----Original Message-----
From: Carl Moreschi <<a
href='n4py3@earthlink.net?'mailto:n4py3@earthlink.net'>n4py3@earthlink.ne
t>
To: wb5jnc <<a
href='wb5jnc@centurytel.net?'mailto:wb5jnc@centurytel.net'>wb5jnc@century
tel.net>;
Discussion of Ten-Tec Equipment <<a
href='tentec@contesting.com?'mailto:tentec@contesting.com'>tentec@contest
ing.com>
Sent: Tue, Jan 26, 2016 3:03 pm
Subject: Re: [TenTec] Model 411 amp (aka Centaur)
Don't overlook the possibility on an intermittent short in one of the 811's.
Carl Moreschi N4PY
58 Hogwood Rd
Louisburg, NC 27549
<a href="http: www.n4py.com" target="_blank">www.n4py.com
On 1/26/2016 2:54 PM, Al Gulseth wrote:
> Joe,
>
> Just an ohms check may not be enough. You may be dealing with an
intermittent
> breakdown under high voltage. A "hi-pot" (high potential) test with an
> insulation tester etc. would be the only way to know for sure. A
winding
> layer to adjacent layer partial short in the HV side could also account
for
> your symptoms, and might not be obvious because the winding resistance
could
> show right at the low edge of the manufacturer's spec. (I went through
that
> scenario years ago with a HV filter choke in a small AM BC
transmitter.)
>
> 73 es GL, Al
>
> On Tue January 26 2016 11:28:03 am Joe Papworth via TenTec wrote:
>> Thanks Andy. Was it the HV secondary that shorted?
>>
>>
>> I isolated the HV secondary from the HV board and it reads open
to the
>> frame and chassis. (Reads about 45 ohms when connected to the
board)
>>
>>
>> Thanks, Joe, K8MP
>>
>>
>> -----Original Message-----
>> From: P C Andy Anderson<<a
href='xtraham58@hotmail.com?'mailto:xtraham58@hotmail.com'>xtraham58@hotm
ail.com>
>> To: Discussion of Ten-Tec Equipment<<a
href='tentec@contesting.com?'mailto:tentec@contesting.com'>tentec@contest
ing.com>
>> Sent: Tue, Jan 26, 2016 11:52 am
>> Subject: Re: [TenTec] Model 411 amp (aka Centaur)
>>
>>
>>
>>
>> Joe, I had a similar problem with my Centurion AMP. It
eventually failed
>> completely. The secondary of the power transformer shorted to the
frame. I
>> had the Xformer rewound at TRS. BTW this transformer problem is a
known.
>>
>> 73' Andy, W3LI
>>
>> ________________________________________
>>
>>
>> Tuesday noontime, Joe:
>>
>> I have a Centaur..............keep it covered when not in use.
>>
>> My Elmer told me to always keep it covered..................dust
is the
>> problem.
>>
>> Even when covered, open it up every two-three years and do a
internal
>> cleaning.
>>
>> N1MHC/alsirois
>> =============
>>
>>
>>
>> Gents,
>>
>>
>> Have any of you gone a few rounds with a Centaur amp?
>> I have a one that blows fuses very intermittently. It vaporizes
them both,
>> simultaneously, so it's apparently a dead-short somewhere. This
happens
>> even in stand-by. (i.e. No key-down)
>>
>>
>> Before I tear into it, anyone have any ideas of common failures
in these
>> amps?
>>
>>
>> Later, Joe, K8MP
>>
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