Yea..... Sure.....
Jim W7RY
> -----Original Message-----
> From: n7rt@cox.net
> Sent: Mon, 23 Aug 2010 19:41:14 -0700
> To: k4vud@hotmail.com, amps@contesting.com
> Subject: Re: [Amps] Can I cool too much the tubes or ants?
>
> To all :
> Melting antennas is a very good sign since I am the last one to relate
> this
> story.
> Circa 1957. San Fernando Valley, CA
> W6HX, Ted Gillete builds a 20 meter amplifier for W6YMD using 2-- 4-1000D
> tubes. They run 7000VDC on the plate at 2 Amps. This causes the driven
> element to glow at the ends as neighbors knock on Bill's door to tell him
> there are invaders from outer space. Actually they worked many AP, VU, &
> 3B8
> that night. The antenna did not survive.
> Anyway that's what was relayed to me.....
> 73 Hardy N7RT
>
>
> ----- Original Message -----
> From: "Charles Harpole" <k4vud@hotmail.com>
> To: <amps@contesting.com>
> Sent: Monday, August 23, 2010 7:03 PM
> Subject: Re: [Amps] Can I cool too much the tubes or ants?
>
>
>>
>> Melting antennas is a very good sign. If u have never done so, ur ham
>> ticket is in jeopardy.
>>
>> Charles Harpole k4vud@hotmail.com
>>
>>
>>
>>> From: sam@owenscommunication.com
>>> To: keepwalking188@yahoo.com; ranchorobbo@gmail.com;
>>> apolloeme@live.com;
>>> amps@contesting.com
>>> Date: Fri, 20 Aug 2010 12:32:34 -0400
>>> Subject: Re: [Amps] Can I cool too much the tubes?
>>>
>>> Could it be the antenna heating up and causing it to click off-line? I
>>> don't know if the amp has any VSWR or Over Current Protection but I
>>> have
>>> had antennas heat up, catch on fire or melt from time to time. My amps
>>> would protect themselves and go to stby when that happened.
>>> N9FUT
>>>
>>> Original Message:
>>> -----------------
>>> From: Jeff Blaine keepwalking188@yahoo.com
>>> Date: Fri, 20 Aug 2010 11:20:53 -0500
>>> To: ranchorobbo@gmail.com, apolloeme@live.com, amps@contesting.com
>>> Subject: Re: [Amps] Can I cool too much the tubes?
>>>
>>>
>>> Gentlemen,
>>>
>>> You should take a look at the plate dissipation at the reduced power
>>> levels.
>>>
>>> In my amp, as the power output drops back, the efficiency drops at a
>>> faster
>>> rate on some bands. Which means that running the amp at half power, for
>>> example, as is the current rule of thumb for RTTY operation, may not
>>> actually reduce the effective plate dissipation very much.
>>>
>>> Of course, one point does not make a trend. But it's easy to make the
>>> calculation and then a guy can KNOW rather than just guess.
>>>
>>> And if we were perhaps talking about an SB220, that transformer is
>>> pretty
>>> light weight to begin with, and a guy would definitely want to check
>>> the
>>> efficiency there.
>>>
>>> Hope to see you in the SARTG.
>>>
>>> 73/jeff/ac0c
>>> www.ac0c.com
>>>
>>>
>>> --------------------------------------------------
>>> From: "Rob Atkinson" <ranchorobbo@gmail.com>
>>> Sent: Friday, August 20, 2010 10:09 AM
>>> To: "Patrick Barthelow" <apolloeme@live.com>
>>> Cc: <amps@contesting.com>
>>> Subject: Re: [Amps] Can I cool too much the tubes?
>>>
>>>> Pat,
>>>>
>>>> I have the amp, manual with schematic. There is nothing in there
>>>> about any sensor that throws the amp in standby if it gets too hot.
>>>> That's why I asked.
>>>>
>>>> It must be an aftermarket mod in your amp Rudy.
>>>>
>>>> But, I am always willing to be surprised and eat crow. Why not give
>>>> Ten Tec a call and ask them? There might be something in there
>>>> having to do with current draw I don't know about, thay may have been
>>>> taken out in later models. Anyway, my comment about specifiying mode
>>>> was not directed at you.
>>>>
>>>> It's up to you whether or not 400 w. is enough, but in my opinion a
>>>> new Alpha is not the answer if you want a really robust amp. If you
>>>> can afford a new Alpha you can afford an old one back before they
>>>> tried to jam everything into a teeny desk-top cabinet, or an old
>>>> Henry, or two, or homebrewing one in a rack....maybe an old TMC or
>>>> Collins commercial communications amp...
>>>>
>>>> On Thu, Aug 19, 2010 at 11:40 PM, Patrick Barthelow
>>>> <apolloeme@live.com>
>>>> wrote:
>>>>>
>>>>> Does anyone have a schematic for the amp under discussion, or perhaps
>>>>> looked
>>>>> to see the sensor device that senses excessive heat to
>>>>> trigger a shutdown? I am curious what they sample for the heat trip
>>>>> function. And, if it is an internal sensor for the transformer core,
>>>>> it
>>>>> might not help, but perhaps some extra muffin fans, mounted external
>>>>> or
>>>>> internal to the amp could add enough cooling to extend its duty cycle
>>>>> on
>>>>> RTTY.
>>>>>
>>>>> Back in the olden days, as a kid, I used to sit a muffin fan right on
>>>>> top
>>>>> of my Drake TR-4 Finals Cage, drawing upward, and the whole radio
>>>>> became
>>>>> and
>>>>> ran dramatically cooler.
>>>>>
>>>>> Best Regards,
>>>>> 73, de Pat Barthelow AA6EG
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>> Date: Thu, 19 Aug 2010 20:16:13 -0700
>>>>>> From: r_bakalov@yahoo.com
>>>>>> To: amps@contesting.com; ranchorobbo@gmail.com
>>>>>> Subject: Re: [Amps] Can I cool too much the tubes?
>>>>>>
>>>>>> Rob,
>>>>>> I am the second owner of this amp and don't know its age. It is the
>>>>>> grey
>>>>>> model. I can certainly look up the serial number when I am back to
>>>>>> VE3
>>>>>> where
>>>>>> my contesting QTH is.
>>>>>> As far as mode goes, my very first post noted that this is with
>>>>>> respect
>>>>>> to
>>>>>> RTTY where I can't really run it longer than 30 min at full power. I
>>> am
>>>>>> not
>>>>>> a SSB guy; CW runs all day long at full power. Standby or not, some
>>> sort
>>>>>> of
>>>>>> protection kicks in when the amps gets too hot and the orange STBY
>>>>>> LED
>>>>>> is
>>>>>> on.
>>>>>> So now my dilemma is if I should run low power, without the amp, or
>>>>>> high
>>>>>> power at only 400 W during the upcoming CQWW RTTY contest :-) Or
>>>>>> time
>>>>>> for an
>>>>>> Alpha :-)
>>>>>> Rudy N2WQ
>>>>>> --- On Thu, 8/19/10, Rob Atkinson <ranchorobbo@gmail.com> wrote:
>>>>>>
>>>>>> From: Rob Atkinson <ranchorobbo@gmail.com>
>>>>>> Subject: Re: [Amps] Can I cool too much the tubes?
>>>>>> To: amps@contesting.com
>>>>>> Date: Thursday, August 19, 2010, 4:28 PM
>>>>>>
>>>>>> Rudy,
>>>>>>
>>>>>> Is this automatic standby mode protection a new thing with the
>>>>>> Centurion? Mine is around 10 years old and it has nothing like this.
>>>>>>
>>>>>> When did you get yours?
>>>>>>
>>>>>> N.B. When you guys write about transmittion time at some power
>>>>>> level,
>>>>>> it is very important that you specify the mode.
>>>>>>
>>>>>> There is a huge difference between "1.5 KW no time limit (operating
>>>>>> SSB) and 1.5 KW no time limit carrier.
>>>>>>
>>>>>> SSB is the "Coors Light" of transmission modes.
>>>>>>
>>>>>> 73
>>>>>>
>>>>>> Rob
>>>>>> K5UJ
>>>>>>
>>>>>>
>>>>>> On Wed, 18 Aug 2010 10:34:58 -0700 (PDT), Rudy Bakalov
>>>>>> <r_bakalov@yahoo.com> wrote:
>>>>>>
>>>>>> >Experience trumps specs. The amp goes into standby mode after about
>>>>>> >30
>>>>>>> minutes
>>>>>> >running at full power, i.e. about 1200 W. If I run it at around
>>>>>> >400-500
>>>>>>> W it
>>>>>> >is fine.
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>>>>>
>>>>>
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