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Title: R390 won't turn off??!! - - - - Post by: W2INR on March 08, 2009, 09:48:11 AM When I go to turn the rig off the light on the Read out stays on. The standby position is working because the receiver goes dead.
Is there a relay? Anyone experienced this or am I just a lucky person? G Title: Re: R390 won't turn off??!! - - - - Post by: Dave KA2J on March 08, 2009, 10:19:51 AM Hi Gary. This is very common. The little micro switch is hanging up. Both of my R-390A's do this on occassion. Turn of the receiver and give the "on/off" knob a lite tap with a soft mallet or piece of wood. Works everytime for me. Dave KA2J
Title: Re: R390 won't turn off??!! - - - - Post by: W2INR on March 08, 2009, 10:42:19 AM Got it Dave. TNX
I shot some De Ox down in there and flipped the switch back and forth two times and it started working. G Title: Re: R390 won't turn off??!! - - - - Post by: W2PHL on March 08, 2009, 05:36:19 PM That little micro switch can be a problem. If it continues to act up, drop the front panel and unscrew the switch from the mounting plate. Be careful not to lose the washers/spacers on the assembly. The switch is riveted together, but it can be GENTLY pried enough to shoot some deoxit straight inside. That should fix it for awhile.
Phil Title: Re: R390 won't turn off??!! - - - - Post by: W1VD on March 08, 2009, 10:30:49 PM The quick fixes only work for a while. Fair Radio sells replacement switches.
Title: Re: R390 won't turn off??!! - - - - Post by: Roy K8VWX on March 09, 2009, 08:07:45 AM I use a thermister for a soft start in the ac line in all my receivers.I have had no trouble with welding of the micro switch contacts in my 390A's since doing so.I don't remember what value I used but use one that can handle the current and have the highest ohmic value COLD. You can see this soft start in the pilot light when first turned on.Do not cut the leads on the thermister and place it away from any other components,wires etc. IT DOES GET HOT. 73/Roy
Title: Re: R390 won't turn off??!! - - - - Post by: Roy K8VWX on March 09, 2009, 11:18:54 AM Just found the thermistor data I used. Mouser part # 527-CL80 3 Amps @ 47 Ohm cold. It is a good Idea if only to save the inrush current on the tube filaments.
Title: Fix it. Post by: KA2PYQ on March 10, 2009, 07:12:48 PM With no power plugged in, work the switch strongly while AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
blowing (maybe through a straw) on any holes on the switch. Allow your breath inside to dry a few minutes. Then squirt some freon through a nozzle or pipe until the switch about turns into an igloo. Work the switch every now and then as the switch goes from cold and snowy to wet to warm and dry. This sometimes cleans things "forever". This works on potentiometers too, and sometimes flakes dirt or grease off too. |