"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 ----------------------------------------------------------------------
