Cooking radars

[gunnarsilins]

I saw a posting here below regarding magnatrons. There was written that a new radar, or one left unused for more than 3 months should be "cooked in" by leaving it in standby mode for at least 30 mins. Not doing this procedure could shorten the life of the most expensive part in the radar up to 50%
I never heard about this and I have not found any information in the manuals for any of the radars I have owned.
I do not doubt the source of this information, but I would be happy to know some about this.

 

[davidwf]

My Radar has a 70 second warming up period, hopefully thats enough.

 

[Guest]

Here is the information

Normally the built in warm up timer in the radar is sufficient. It allows time for the filament to reach temperature and also for any gas molecules that have migrated out of the magnetron components to be absorbed before the high voltage is applied.

HOWEVER

If your radar has been off for more than about a year, you should extend the warm up period for a couple of minutes for every month it has been turned off to give any excess escaped gas molecules more time to be removed.

I blew the magnetron on my radar through not knowing this. When I replaced the magnetron, this information was included with the installer's instructions. It applied in particular to a magnetron that may have sat on a vendors shelf for a couple of years and suggested at least a 1/2 hour warm up time. I presume that the necessity for this decreases with age as fewer gas molecules will be available to escape into the vacuum but the one I blew was quite old and had been idle for over a year.

I can't explain why this important information is not included in the radar owner's manuals - it would have saved me a bunch of money.

tech@yandina.com

 

[Guest]

Colin is correct in his explanation. It is not the physical heating but the ionisation. Even turning off the radar and back on again immediately would not effect a temperarure difference by much, yet the standby timer starts again, which should tell you something. Keep in mind the power capacity of magnetrons vary from 2,000 Watts to 25,000.