Thanks to the list for this idea, made a good morning project. I'd found a junk PC fan just the right size, and found a 5V wall wart from an old cellphone, and even the right long screws which threaded into the fan just right.
Chuck, K1OM On Dec 26, 2007 1:33 PM, Howard Traxler <[EMAIL PROTECTED]> wrote: > > "Howard Traxler" <[EMAIL PROTECTED]> made an utterance to the > drakelist gang > ---------------------------------------------------------------------- > Well yes, I'm sure it will live longer; not sure about prosper. A friend > gave me that thought in 1969; just a "something to think about". He's > dead > now. Thought I'd throw it out for comments and I got some, thanks. I > think > I'll look for a couple little fans. > > WA9RYF > ----- Original Message ----- > From: "Dennis Monticelli" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Tuesday, December 25, 2007 12:01 AM > Subject: Re: [drakelist] Cooling Fan on finals > > > : > : "Dennis Monticelli" <[EMAIL PROTECTED]> made an utterance to > the > drakelist gang > : ---------------------------------------------------------------------- > : Just a moderate amount of air assist makes a big difference in terms > : of reducing peak component temp, reducing temp gradients, and > : minimizing temp change between TX and RX modes. > : > : As for the Drakes being built to run at that elevated temp and > : performing worse if run cooler, I find that very hard to believe. The > : only scientific basis I can find for it (and a weak argument at that) > : is non-linear temp correction was used in the design. In other words, > : parabolic parameter change with temp for certain temp compensation > : components was established at a given elevated temp. But this degree > : of sophistication of temp correction was probably beyond the bag of > : tricks at the disposal of the Drake designers at the time. And it > : does not explain that temp reduction properly done will also reduce > : temp change and that helps out any circuit, however the temp > : compensation is performed. > : > : Bottom line, cool the sucker. It will live long and prosper. > : > : Dennis AE6C > : > : On Dec 24, 2007 9:11 PM, Garey Barrell <[EMAIL PROTECTED]> wrote: > : > > : > Garey Barrell <[EMAIL PROTECTED]> made an utterance to the > drakelist > gang > : > ---------------------------------------------------------------------- > : > Peter - > : > > : > I haven't, but I can tell you that the cabinet top of the T-4X(any) > can > : > be too hot to comfortably hold you hand on it after extended > : > transmission, especially on high duty cycle modes such as RTTY and AM. > : > Even on CW or SSB this area can get quite warm. Of course this is > even > : > more evident with the TR-3/4 series with 50% more dissipation in only > a > : > slightly larger cage. > : > > : > On the other hand, with a small, silent fan exhausting air out the > back > : > of the PA cage the cabinet top is only slightly warmer than the rest > of > : > the cabinet, even after long transmissions. The fan really makes a > big > : > difference in that area, and in the rest of the cabinet as well. > : > > : > 73, Garey - K4OAH > : > St Charles, IL > : > > : > > : > Peter Bent wrote: > : > > "Peter Bent" <[EMAIL PROTECTED]> made an utterance to the drakelist > gang > : > > > ---------------------------------------------------------------------- > : > > Just curious, has anyone actually measured the temps in the cages-- > before > : > > and after? > : > > > : > > -----Original Message----- > : > > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On > : > > Behalf Of Ron Wagner > : > > Sent: Monday, December 24, 2007 8:18 PM > : > > To: [EMAIL PROTECTED] > : > > Subject: Re: [drakelist] Cooling Fan on finals > : > > > : > > > : > > Ron Wagner <[EMAIL PROTECTED]> made an utterance to the drakelist gang > : > > > ---------------------------------------------------------------------- > : > > The way I went about his was a half wave (single diode) and filter > cap > : > > from the 12VAC filament line. I drive a 24 volt fan drawing air out > of > : > > the final cage. Turns the fan on as I turn on the rig, shuts down > when > : > > turned off. Runs slow and quit, but really makes a difference on > the > : > > temp of the final cage. I attach the fan to the rear of the cage > (so > the > : > > cabinet comes off without problems) with grommets and black nylon > wire > : > > ties. This arrangement does not seem to damage the cabinet, and > does > a > : > > nice job cooling. > : > > > : > > As far as stability, as long as you do not blow the warm air in, it > should > : > > make the rig more stable. The cabinet and associated circuits > should > : > > stay much more constant in temperature. In a good oscillator > design, > : > > which Drake has, it is typically temperature change that causes the > drift. > : > > > : > > 73, > : > > Ron WD8SBB > : > > > : > > > : > > : > ---------------------------------------------------------------------- > : > Submissions: [EMAIL PROTECTED] > : > Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in > body > : > Hopelessly Lost: [EMAIL PROTECTED] - help in body of message > : > Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net > : > ---------------------------------------------------------------------- > : > > : > : ---------------------------------------------------------------------- > : Submissions: [EMAIL PROTECTED] > : Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in > body > : Hopelessly Lost: [EMAIL PROTECTED] - help in body of message > : Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net > : ---------------------------------------------------------------------- > : > : > : -- > : No virus found in this incoming message. > : Checked by AVG Free Edition. > : Version: 7.5.516 / Virus Database: 269.17.9/1197 - Release Date: > 12/25/2007 8:04 PM > : > > > ---------------------------------------------------------------------- > Submissions: [EMAIL PROTECTED] > Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body > Hopelessly Lost: [EMAIL PROTECTED] - help in body of message > Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net > ---------------------------------------------------------------------- >
