[Amps] GU-84b Cooling

Wed Jul 20 08:23:47 EDT 2005

I read this today on the amps reflector.

"On a webpage somewhere, I cant remember now where, I read about
the GU-84B (4CX1600) having an undersized radiator"

The GU-84B tube is NOT the same tube as the 4cx1600 tube.......they are 
entirely different in size, and power output.

There was a tube called the GU-91B that is almost identical to the 4cx1600b 
tube......the only difference being the GU-91B does have a slightly smaller 
radiator than the 4cx1600b tube.......The GU-91B WILL WORK IN PLACE OF THE 
4CX1600B TUBE.....The only thing you need to watch out for is that if you do 
a lot of continious duty type modes like RTTY or SSTV ect, the GU-91B could 
overheat unless you are careful........but for normal SSB useage, the GU91B 
will work just fine.

I hope I have not confused the issues here, (my mind is still a little foggy 
after my hospital stay) but if I have got things mixed up please excuse my 
mistake.

73

Tom.....w4th......Tom's Tubes

Tom's Tubes: Amateur Radio Amp Tubes & Sockets, CTHRD Hand Made CW Keys, 
K4POZ Screwdriver Antennas & G3SEK Triode/Tetrode Boards & Kits. 
http://www.tomstubes.com

----Original Message Follows----
From: amps-request at contesting.com
Reply-To: amps at contesting.com
To: amps at contesting.com
Subject: Amps Digest, Vol 31, Issue 35
Date: Wed, 20 Jul 2005 07:47:12 -0400

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Today's Topics:

1. Re: Amps Digest, Vol 31, Issue 34 (K3vw at aol.com)
2. GU-84B Cooling (Will Matney)
3. Re: GU-84B Cooling (Dan K9ZF)
4. Fw: GU-84B Cooling (PA3DUV)
5. Re: GU-84B Cooling (gdaught6 at stanford.edu)
6. Re: GU-84B Cooling (Will Matney)
7. Re: GU-84B Cooling (R.Measures)
8. Re: GU-84B Cooling (R.Measures)
9. Re: GU-84B Cooling (pa3duv at planet.nl)

----------------------------------------------------------------------

Message: 1
Date: Tue, 19 Jul 2005 13:35:41 EDT
From: K3vw at aol.com
Subject: Re: [Amps] Amps Digest, Vol 31, Issue 34
To: amps at contesting.com
Message-ID: <42.6d6427b6.300e93ed at aol.com>
Content-Type: text/plain; charset="US-ASCII"

Did he run it grounded grid? What is filament voltage/ current of a GU-84B ?
Did he have to build a socket or can you buy them. What is plate disapation
of the 84B ? I think 2500 watts. Willy

------------------------------

Message: 2
Date: Tue, 19 Jul 2005 14:53:19 -0500
From: "Will Matney" <craxd at engineer.com>
Subject: [Amps] GU-84B Cooling
To: amps at contesting.com
Message-ID: <20050719195320.5FB054BEAD at ws1-1.us4.outblaze.com>
Content-Type: text/plain

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
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------------------------------

Message: 3
Date: Tue, 19 Jul 2005 15:15:14 -0500
From: Dan K9ZF <n9rla at yahoo.com>
Subject: Re: [Amps] GU-84B Cooling
To: Will Matney <craxd at engineer.com>
Cc: amps at contesting.com
Message-ID: <42DD5F52.7030806 at yahoo.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Will Matney wrote:

>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.
>
>Best,
>
>Will
>
>
>

Water cool it?

73
Dan

--
K9ZF /R no budget Rover ***QRP-l #1269
Check out the Rover Resource Page at: <http://www.qsl.net/n9rla>
List Administrator for: InHam+grid-loc+ham-books

------------------------------

Message: 4
Date: Tue, 19 Jul 2005 23:19:26 +0200
From: PA3DUV <pa3duv at planet.nl>
Subject: [Amps] Fw: GU-84B Cooling
To: amps at contesting.com
Message-ID: <025101c58ca7$8afbc4f0$6c9a390a at TVLT001>
Content-Type: text/plain; format=flowed; charset=iso-8859-1;
reply-type=response

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 at engineer.com>
>To: <amps at 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 at contesting.com
>>http://lists.contesting.com/mailman/listinfo/amps
>

------------------------------

Message: 5
Date: Tue, 19 Jul 2005 15:47:47 -0700
From: gdaught6 at stanford.edu
Subject: Re: [Amps] GU-84B Cooling
To: amps at contesting.com
Message-ID: <42DD20A3.19877.1A01FDD at localhost>
Content-Type: text/plain; charset=US-ASCII

On 19 Jul 2005 at 14:53, Will Matney wrote:

>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.

The radiator is comparatively small. But why not take to heart what
Rich, AG6K, says? "The only time there's too much cooling air is
when it blows the tube out of the socket!" (or something like that.)

If the blower is too loud, wear headphones. I wear them all the
time.

73,

George T. Daughters, K6GT

------------------------------

Message: 6
Date: Wed, 20 Jul 2005 03:12:04 -0500
From: "Will Matney" <craxd at engineer.com>
Subject: Re: [Amps] GU-84B Cooling
To: Amps at contesting.com
Message-ID: <20050720081204.3E61C4BEAD at ws1-1.us4.outblaze.com>
Content-Type: text/plain; charset="iso-8859-1"

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 at planet.nl>
To: "Will Matney" <craxd at 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 at engineer.com>
>To: <amps at 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 at contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps

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___________________________________________________________
Sign-up for Ads Free at Mail.com
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------------------------------

Message: 7
Date: Wed, 20 Jul 2005 04:02:10 -0700
From: R.Measures <r at somis.org>
Subject: Re: [Amps] GU-84B Cooling
To: "Will Matney" <craxd at engineer.com>
Cc: Amps at contesting.com
Message-ID: <0695c7b77d5d4292cc35d734e726c82b at somis.org>
Content-Type: text/plain; charset=US-ASCII; format=flowed

On Jul 20, 2005, at 1:12 AM, Will Matney wrote:

>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.

An IR thermometer would work.

>...
>
>----- Original Message -----
>From: PA3DUV <pa3duv at planet.nl>
>To: "Will Matney" <craxd at 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 at engineer.com>
>>To: <amps at 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 at 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 at contesting.com
>http://lists.contesting.com/mailman/listinfo/amps
>
>

Richard L. Measures, AG6K, 805.386.3734. www.somis.org

------------------------------

Message: 8
Date: Wed, 20 Jul 2005 04:07:27 -0700
From: R.Measures <r at somis.org>
Subject: Re: [Amps] GU-84B Cooling
To: Dan K9ZF <n9rla at yahoo.com>
Cc: amps at contesting.com
Message-ID: <fffd55ee21291825e84cf7ea3237c09a at somis.org>
Content-Type: text/plain; charset=US-ASCII; format=flowed

On Jul 19, 2005, at 1:15 PM, Dan K9ZF wrote:

>Will Matney wrote:
>
>>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.
>>
>>Best,
>>
>>Will
>>
>>
>>
>
>Water cool it?

Large electric generators are cooled with hydrogen gas, which removes
heat c. 5-times more efficiently than air-cooling.
>
>73
>Dan
>
>--
>K9ZF /R no budget Rover ***QRP-l #1269
>Check out the Rover Resource Page at: <http://www.qsl.net/n9rla>
>List Administrator for: InHam+grid-loc+ham-books
>
>
>_______________________________________________
>Amps mailing list
>Amps at contesting.com
>http://lists.contesting.com/mailman/listinfo/amps
>
>

Richard L. Measures, AG6K, 805.386.3734. www.somis.org

------------------------------

Message: 9
Date: Wed, 20 Jul 2005 13:47:04 +0200
From: pa3duv at planet.nl
Subject: Re: [Amps] GU-84B Cooling
To: amps at contesting.com
Message-ID: <18c76a518ce2e4.18ce2e418c76a5 at planet.nl>
Content-Type: text/plain; charset=us-ascii

Van pa3duv at planet.nl
Verstuurd op woensdag, juli 20, 2005 11:49 am
Aan Will Matney <craxd at 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 at 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 at planet.nl>
>To: "Will Matney" <craxd at 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 at engineer.com>> To: <amps at 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 at 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 at contesting.com
>http://lists.contesting.com/mailman/listinfo/amps
>

------------------------------

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End of Amps Digest, Vol 31, Issue 35
************************************