[ICOM] 756 ProII Temp Problem

[D C Macdonald]

I suspect that continuous fan operation at a slower
speed (and noise) actually gives  MORE  total cooling
air in the long run than the intermittent higher speed
operation.

Mac, K2GKK/5
Oklahoma City



----Original Message Follows----
From: "MikeR" <nf4l at nf4l.com>
Reply-To: ICOM Reflector <icom at mailman.qth.net>
To: "ICOM Reflector" <icom at mailman.qth.net>
Subject: Re: [ICOM] 756 ProII Temp Problem
Date: Wed, 22 Sep 2004 18:26:49 -0400

Bill -
I'm puzzled as to how a slower running fan could result in more cooling.
Less noise, sure. BTW I have a PROII and it does get very warm just sitting
there, but so far (crossed fingers) so good.
73, Mike NF4L



----- Original Message -----
From: "Bill Archer" <bfarcher at comcast.net>
To: "ICOM Reflector" <icom at mailman.qth.net>
Sent: Wednesday, September 22, 2004 9:08 AM
Subject: [ICOM] 756 ProII Temp Problem

 > As the proud owner of both a 706MkIIG and a ProII I have been following
the
 > discussion on cooling the ProII during extend RX periods.
 >
 > The 706 has a similar problem in that the case temp would get VERY warm
 > while in RX. A simple fan mod whereby a 200 ohm 1 Watt resister was place
 > between a +12v source and the + lead on the cooling fan. This causes the
 > cooling fan to run at a low speed with about 4.7V applied to the fan. The
 > effect of this mod is the case temp is reduced by  about 30° F.
 >
 > It would seem to me that a similar approach could be taken with the ProII
to
 > apply a reduced voltage to the cooling fan to achieve the same results.
 >
 > Since this reflector is blessed with an abundance of talented and
 > knowledgeable techno-wizards
 > would any of you care to comment on this approach?
 >
 > KC5GNB
 > Bill in Plano