[Moon-net] AIR FLOW 3CX1500

[Peter Voelpel]

I imagine the back pressure on the blower is caused by the tube itself and
not by the compartment.
The construction of the anode cooler, size, density of the fins etc. are
responsible for the back pressure and can not be reduced at a given air flow

73
Peter

-----Original Message-----
From: Moon-net-bounces at list-serv.davidv.net
[mailto:Moon-net-bounces at list-serv.davidv.net] On Behalf Of Lance Collister
Sent: Freitag, 18. August 2006 15:16
To: Pat Barthelow
Cc: Moon-net at list-serv.davidv.net
Subject: Re: [Moon-net] AIR FLOW 3CX1500

Pat Barthelow wrote:

>Philippe:
>
>Re heavy duty use of the 3CX 1500  (8877) on 2m, the site:
>
>http://www.g8wrb.org/data/Eimac/3CX1500A7.pdf
>
>Shows for HF, a minimum of 38 CFM at .6 " Hg  backpressure is required,
with 
>higher values called for at higher frequencies.
>That is a pretty strong blast of air,  requiring a pretty strong squirrel 
>cage type blower...Or, If I was building it  here in the US, I might go to 
>Walmart, and find a cheap, small Shop Vac Vacuum Cleaner and route its 
>output hose into the amp air plumbing, from some distance, or through the 
>wall of the shack to minimize in-shack noise.   Good luck...
>
>73, DX, de Pat AA6EG aa6eg at hotmail.com;
>                  Skype:  Sparky599
>
>  
>
>>From: "F1DUZ" <duz at wanadoo.fr>
>>To: "Moon-net" <Moon-net at list-serv.davidv.net>
>>Subject: [Moon-net] AIR FLOW 3CX1500
>>Date: Fri, 18 Aug 2006 10:01:01 -0000
>>Hi all,
>>
>>I would like to use a 3cx1500 on 2m in JT65, what is the minimum air flow 
>>needed to have a good and safe cooling (in CFM or m3/h ) ?
>>
>>Thanks for answer
>>
>>best 73 all
>>Philippe
>>F1DUZ IN97nj
>>Philippe Levron
>>Malvaux
>>49570 Montjean-sur-Loire
>>France
>>duz at wanadoo.fr
>>    
>>
>
>
>
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>  
>
You will be surprised at how much air you can get from a blower if you 
reduce the back pressure on it.  Here in my shack, I have used high 
volumne fans to "suck" air out of the top of the tank compartment to 
reduce the back pressure on the blower and let it really push the cool 
air through the tube.  Here is a photo of the way I did this on 8877 
amps for 2m and 6m:

http://www.bigskyspaces.com/w7gj/W7GJ8877AMPS.jpg

GL and VY 73, Lance


-- 
Lance Collister, W7GJ (ex: WN3GPL, WA3GPL, WA1JXN, WA1JXN/C6A, ZF2OC/ZF8)
P.O. Box 73
Frenchtown, MT  59834  USA
QTH: DN27UB
TEL: (406) 626-5728
URL: http://www.bigskyspaces.com/w7gj
2m DXCC #11/6m DXCC #815


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