[AMRadio] Intermittent Filament Pin

[Bill Fondren]

This may seem to be a simple question but I have a 100th modulator tube that has a intermittent filament pin.  I have resoldered it a dozen times and it may operate for 2 weeks or 5 minutes.  Its in a BC 610 that I have just redone and have had it on for about 2 weeks.  the tube is a new or nos.  Is there a special type solder that would be better to use than just regular radio type solder    Bill Fondren K5PML