Hello Jordan, You should have figured it already, but... It will be impossible to diagnose temporary shorts between the plates of C225 A+B as long as all the antenna coils are left in place, because they have a so low resistance value on their secondaries that this will mask any leakage coming from the variable capacitor sections. Check the schematic, you will see it.
What I believe can be done by leaving C225A+B in place is: 1_ Tune MHz knob to 00. 2_ Locate T201 and remove the related slugs rack. Take care to not loose the springs in the RF deck... 3_ Remove T201: with the MHz tune in 00 position, the A+B sections of C225 are connected in parallel between pins 3 and 6 of the T201 socket. 4_ Using a sensitive ohmmeter connected between those pins, any (even temporary) leakage of the capacitors can be measured, and with a capacitance meter connected to the same pins, the total value of the variable sections can be checked for any rotation angle of the control shaft. Let us know... 73, Jacques, VE2JFE in Montreal Hi again group... I'm ready to re-mount the RF deck temporarily in the radio, but before I do that, I'd like to know if there is a test technique or method I haven't tried yet. I was getting some scratching noises and "dead spots" at some positions of the Ant Trim control. After an attempt at repair, without being able to pull the variable cap out of the can, I've used a 50 Mohm impedance VTVM with a 500 Mohm scale as well as the Insulation test of my Sprague TO-6 and checked between every line and each line to ground and I can't provoke even the slighest twitch of the metering when rotating the cap Is there anything else I should try..? 73...Jordan VE6ZT ______________________________________________________________ R-390 mailing list Home: http://mailman.qth.net/mailman/listinfo/r-390 Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
