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MrVa1ve · 6th Mar 2017, 5:02 pm

Hi,

I have a Philips 310 with a broken variable capacitor blade. The vcap is in two sections and each section is 500pF (measured as 520pF on the LCR meter).

The broken blade is the end rotor blade of the LO section (I think - I'll confirm later). In fairness, this blade is the most delicate since the end blades in this model (they have sun-burst style gaps in the metal) are not secured by a tie-bar across the top and so are only secured to the axle. When I went to straighten the blade (as delicately as I could) - snap! ******!

I've tried soldering the broken blade back to the axle and whilst it's holding sort-of, I'm not entirely happy. It seems my venerable soldering iron isn't hot enough to out-do the thermal mass of the axle plus blade. Also, I'm not entirely sure the axle will take solder properly anyway.

Here are some of the options I've considered; feedback and comments greatly appreciated!

1) Dismantle it completely and try a better soldering effort. Does the axle readily accept solder?

2) Carry on without the blade. It measures as 500pF minus blade, so maybe I could try re-tuning the relevant section?

3) Add additional capacitance using trimmer

Regards.

6th Mar 2017, 5:02 pm	#1
MrVa1ve Tetrode Join Date: Mar 2017 Location: Dublin, Ireland Posts: 75	Variable Capacitor Blade Broke Off Hi, I have a Philips 310 with a broken variable capacitor blade. The vcap is in two sections and each section is 500pF (measured as 520pF on the LCR meter). The broken blade is the end rotor blade of the LO section (I think - I'll confirm later). In fairness, this blade is the most delicate since the end blades in this model (they have sun-burst style gaps in the metal) are not secured by a tie-bar across the top and so are only secured to the axle. When I went to straighten the blade (as delicately as I could) - snap! ******! I've tried soldering the broken blade back to the axle and whilst it's holding sort-of, I'm not entirely happy. It seems my venerable soldering iron isn't hot enough to out-do the thermal mass of the axle plus blade. Also, I'm not entirely sure the axle will take solder properly anyway. Here are some of the options I've considered; feedback and comments greatly appreciated! 1) Dismantle it completely and try a better soldering effort. Does the axle readily accept solder? 2) Carry on without the blade. It measures as 500pF minus blade, so maybe I could try re-tuning the relevant section? 3) Add additional capacitance using trimmer Regards.