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.
> >>> _______________________________________________
> >>> Amps mailing list
> >>> Amps@contesting.com
> >>> http://lists.contesting.com/mailman/listinfo/amps
> >>> _______________________________________________
> >>> Amps mailing list
> >>> Amps@contesting.com
> >>> http://lists.contesting.com/mailman/listinfo/amps
> >>
> >>
> > _______________________________________________
> > Amps mailing list
> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
> >
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>
> --------------------------------------------------------------------
> mail2web - Check your email from the web at
> http://link.mail2web.com/mail2web
>
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|