Amps
[Top] [All Lists]

Re: [Amps] GU-84B Cooling

To: "Gary Smith" <wa6fgi@sbcglobal.net>, "PA3DUV" <pa3duv@planet.nl>,<amps@contesting.com>
Subject: Re: [Amps] GU-84B Cooling
From: "Gary Smith" <wa6fgi@sbcglobal.net>
Reply-to: Gary Smith <wa6fgi@sbcglobal.net>
Date: Wed, 20 Jul 2005 07:32:23 -0700
List-post: <mailto:amps@contesting.com>
my error, the url is www.towerhobbies.com
Gary
  ----- Original Message ----- 
  From: Gary Smith 
  To: PA3DUV ; amps@contesting.com 
  Sent: Wednesday, July 20, 2005 7:29 AM
  Subject: Re: [Amps] GU-84B Cooling


  To the list: 
  In this thread is the mention of IR thermometers.  As I fly r/c airplanes, 
such thermometers for reading cylinder head temps have found their way into my 
hobby.  Raytek is one brand name, it sells for $70.00 or so.  Go to 
www.towerehobbies.com and search for temperature gauge, found one that read +- 
2% from -27 to 428 Fahrenheit.  Price is $24.95, comes with many features 
including a "temp hold." 
  A price such as this beats the dickens of having to pay for a lab grade 
instrument.
  73 to all,
  Gary... wa6fgi  
    ----- Original Message ----- 
    From: PA3DUV 
    To: amps@contesting.com 
    Sent: Wednesday, July 20, 2005 4:56 AM
    Subject: Re: [Amps] GU-84B Cooling


    oops.. UV should read IR...
    Thanks Rich.

    ----- Original Message ----- 
    From: <pa3duv@planet.nl>
    To: <amps@contesting.com>
    Sent: Wednesday, July 20, 2005 1:47 PM
    Subject: Re: [Amps] GU-84B Cooling


    > Van   pa3duv@planet.nl  
    > Verstuurd op  woensdag, juli 20, 2005 11:49 am 
    > Aan  Will Matney <craxd@engineer.com>  
    > Cc    
    > Bcc    
    > Onderwerp  Re: [Amps] GU-84B Cooling 
    > Will,
    > 
    > Perhaps I could measure the anode cooler temperature with a UV 
    > thermometer.
    > "Contesting conditions" is a rather vague performance indicator, I 
    > could run the amplifier flat out full carrier for a defined period of 
    > time and then measure the cooler temperature afterwards.
    > I will set up a measurement session, measuring the pressure in the sub 
    > chassis in mm-H2O and the temperature in degrees Celcius. It is very 
    > difficult to measure the actual airflow without proper anemometers and 
    > a measurement-tube. 
    > 
    > The B+ current is approx. 3.5 amps @ 6000 watt output. The power gain 
    > is approx 20 dB and the output power is adequate. The 3-phase B+ 
    > transformer is switched in a delta configuration, AC voltage between 
    > the phases is approx 390 VAC @ 50 Hz. The airflow noise is of no 
    > concern to me since I always use a headset. I'll get back with some 
    > more detailed measurements later on.
    > 
    > Cheers, Dick Knol
    > PA3DUV
    > 
    > 
    > 
    > ----- Oorspronkelijk bericht -----
    > Van: Will Matney <craxd@engineer.com>
    > Datum: woensdag, juli 20, 2005 10:12 am
    > Onderwerp: Re: [Amps] GU-84B Cooling
    > 
    >> Dick,
    >> 
    >> I'm not saying it's a bad tube, and dont want none to think that. 
    >> I just dont want anyone to undercool the tube so it will last. Who 
    >> knows, the 4CX1500 may have an over-sized radiator too! About the 
    >> only way to tell about the temp would be to use a thermocouple 
    >> connected to the anode. Then the temp read under contesting 
    >> conditions both under SSB and AM using the air flow they 
    >> recommend. AM/CW creates a good bit more load on one as does SSB 
    >> transmissions. Then if the temp stays down where it should, one 
    >> would know it would be ok. I'm like Rich, and what George 
    >> mentioned, use the largest blower possible. Another thing too is 
    >> maybe mount and external blower and duct it to the amp. You can 
    >> set one of these in another room to help kill the sound down if 
    >> it's a concern. On yours, you may have the right combination by 
    >> using enough fans both pushing and pulling. Have you measured what 
    >> the air flow and pressure is on your amp? If so, let us know so we 
    >> all have a starting point.
    >> 
    >> Best,
    >> 
    >> Will
    >> 
    >> ----- Original Message -----
    >> From: PA3DUV <pa3duv@planet.nl>
    >> To: "Will Matney" <craxd@engineer.com>
    >> Subject: Re: [Amps] GU-84B Cooling
    >> Date: Tue, 19 Jul 2005 22:45:03 +0200
    >> 
    >> > 
    >> > Will,
    >> > In my twin tube GU84B amp one fan is used to pressurize the 
    >> > subchassis and two axial fans to draw the air out.
    >> > With a B+ of 2900 VDC, from the 3 phase PSU the two GU84B tubes 
    >> > generate an easy 6 kW of output. During normal (6 dB compressed) 
    >> > SSB transmissions the exaust air stays below 55 degrees celcius.
    >> > Cheers, Dick Knol
    >> > PA3DUV
    >> > 
    >> > 
    >> > 
    >> > ----- Original Message ----- From: "Will Matney" 
    >> <craxd@engineer.com>> To: <amps@contesting.com>
    >> > Sent: Tuesday, July 19, 2005 9:53 PM
    >> > Subject: [Amps] GU-84B Cooling
    >> > 
    >> > 
    >> > > On a webpage somewhere, I cant remember now where, I read 
    >> about 
    >> > > the GU-84B (4CX1600) having an undersized radiator. I think it 
    >> > > was on a Russian amateur website. What I had read was this 
    >> tube 
    >> > > was actually designed for running in a missle by the Russians, 
    >> > > and was designed for a 1 time use. So, they undersized the 
    >> > > radiator a good bit because of space limitations. They were 
    >> > > making the comparison to a 4CX1500's radiator size being 
    >> larger 
    >> > > in the discussion. However the guts of the GU-84B supposed to 
    >> be 
    >> > > really good. So this brings the delima of how to cool it so 
    >> one 
    >> > > would get a long life out of it. One way would be add some 
    >> sort 
    >> > > of extra aluminum heat fins, or some made of brass, with fins 
    >> > > sticking out to catch more air, thus increasing the overall 
    >> > > surface area. The only other way would be to increase the 
    >> amount 
    >> > > of air flow and volume over the fins that's there. When doing 
    >> > > this though, the noise goes up from the blower. However, if 
    >> one 
    >> > > is going to dealve into using the GU-84B, I'd s
    >> > > uggest looking into this and compare the sizes between its 
    >> > > radiator and the one for the 4CX1500. Even though the tube is 
    >> > > cheaper than some others, it's still expensive if you have to 
    >> > > re-tube all the time. If I can remember where I seen this, 
    >> I'll 
    >> > > post the link.
    >> > >
    >> > > Best,
    >> > >
    >> > > Will
    >> > >
    >> > > -- ___________________________________________________________
    >> > > Sign-up for Ads Free at Mail.com
    >> > > http://promo.mail.com/adsfreejump.htm
    >> > >
    >> > > _______________________________________________
    >> > > Amps mailing list
    >> > > Amps@contesting.com
    >> > > http://lists.contesting.com/mailman/listinfo/amps
    >> 
    >> 
    >> -- 
    >> ___________________________________________________________
    >> Sign-up for Ads Free at Mail.com
    >> http://promo.mail.com/adsfreejump.htm
    >> 
    >> _______________________________________________
    >> 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
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps

<Prev in Thread] Current Thread [Next in Thread>