In my industry we also use rack mounting which is quite the reverse , with fan
forced air flow to move the heat so in my experience I stick by the comments
.Frankly having just installed a 3000 va ups here recently I prefer it being
off the floor anyway .
To: Repeater-Builder@yahoogroups.com
From: [EMAIL PROTECTED]
Date: Sat, 24 Nov 2007 16:14:59 -0800
Subject: RE: [Repeater-Builder] 19" rack positioning question
Barry,
With all due respect, I think the appropriate response to your statement is:
"Not necessarily."
The typical Motorola Micor 100 watt repeater station will have the duplexer
at the very bottom of the cabinet, with the power supply just above it.
Then follows the unified chassis, and finally the 100 watt PA at the top.
While your desire for cooling fans is well-intended, I daresay that the vast
majority of 100 watt Micor stations- many of which remain in service today-
are cooled solely by convection, and they seem to survive without fans.
Let us keep in mind that fans do not "cool" anything; they simply move air
around. If the ambient temperature in an uncooled transmitter shack is 120
degrees Fahrenheit, the fan will simply raise the temperature inside the
cabinet to 120 degrees F- which might be higher than the temperature inside
the cabinet if no fans were used.
73, Eric Lemmon WB6FLY
-----Original Message-----
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of Barry C'
Sent: Saturday, November 24, 2007 3:37 PM
To: repeater-builder@yahoogroups.com
Subject: RE: [Repeater-Builder] 19" rack positioning question
Just remember heat rises so the hottest items usually go high in the stack ,
assuming you have a top mounted fan.
________________________________
To: Repeater-Builder@yahoogroups.com
From: [EMAIL PROTECTED]
Date: Sat, 24 Nov 2007 18:50:41 +0000
Subject: [Repeater-Builder] 19" rack positioning question
In the sprit of the only stupid question is the one that goes un-
asked.
Here goes:
I have a Micor UHF repeater mounted in a 46" x 19" cabinet.
It is now a ham band repeater that I have added a new NHRC-5
controller and IRLP interface. The modules are mounted as follows:
Top: Custom built 12V PA cooling fan rack controlled by the NHRC-5
aligned with the top door vents.
75W PA
Transmitter/ Antenna Network
Control module (mostly empty now replaced with NHRC-5 and mods from
this site)
Receiver module
Massive TPN1110B power supply
4" space
Bottom: WaCom duplexer cannisters (4)
I would like to put the power supply on the bottom so that it aligns
with the vents in the cabinet doors and I can add some fans to cool
the transformer (you can cook a grilled cheeze sandwitch on it) An
added plus is that it will make the cabinet more stable with the
weight on the bottom.
Is there any issues mounting the duplexers between the receiver and
the power supply with the powersupply on the bottom.
I hate to move things around and have problems.
And yes I will get help to lower the power supply and save some
digits. I know the best solution is to replace the powersupply with
a
more modern one. I plan to do this when funds are better. When this
time comes who makes the best replacement powersupply unit? (ok two
Questions)
Thanks gang
Bill N5ZTW
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