I bought a nice shortwave phillips radio a 114-K. I have been looking for a nice shortwave set to restore for a while.
I opened it up and gave it a clean and recapped the whole thing straight away. When I turned on power to the beast the 6X5GT rectifier gave me a nice little lightning show, then promptly died. Putting it down to an old tube, I bought another and installed it, same thing.
So I bought a lot of 5 of the tubes cheap of ebay just incase I managed to have 2 dodgy tubes (unlikely I know), put a third one in and lost that too.
Over the duration of the three tubes I have checked everything I can think of, made sure there is no crossed wires checked polarity of electrolytic caps and even checked that the pins are clean.
Any other suggestions? This was meant to be a fun project...

Dear Marcus,

Indeed it is fun, except when things go horribly wrong. First thing I would do is take the chassis out, remove all valves, up-end the chassis so that it can be probed with a multimeter, making sure that the chassis cannot move and then apply power to the chassis. Next step is to test the rectifier filament voltage on the rectifier's valve socket. If it is higher than 6.3 volts then it is likely that you have a shorted high tension winding in your power transformer. The plate voltage should be about 325. Again, any higher and there is a big problem.

Polarity of condensers shouldn't result in a higher voltage. If they are oriented the wrong way they'll let you know about it very quickly - they'll explode, showering the bottom of your chassis with the foil innards. One thing I would check with the condensers is that they are only on the high tension circuit. Triple check your connections there.

Dear Marcus....just been crusing through the archives and came across this.

Ya gotta be kidding....3 rectifier blow-ups in succession.?! Could have been worse and blown them all LOL. What did you eventually find after Brad's spot-on advice?

6X5's are notorious for going short heater to cathode and some designs of them are worse than others.

Check this with an ohm meter. Cathode is pin 8 Heaters 2 & 7

Has this got 6 Valves?

Have a look at the valve socket Rectifier & fingers out

Using a Voltmeter on AC measure from pins 2 to 7 should be 6.3V approx. If not or the pin number 7 has nothing on it? Check pins 2 and 8 &see if there is 5V.

If there is then its the wrong valve & possibly not that model.

Do not feed it any more valves. Check that you did not miss changing any paper or electrolytic's and that the electrolytics are the correct way around.

This looks very much like a HT short. As you have worked on it, check for short circuited wires, misplaced wires and especially solder dags that have mangaged to get where they should not be. Alo check that the valves are in correct order & place?

6SQ7 in the wrong place can be interesting as it's heaters are 1 & 8 not 2 & 7 like the rest of them.

Marc