Hi all, I recently obtained an early vacuum tube tester (Radio City Products 314 model). It has obviously been stored in a very damp area and it has taken some time to get all the switches and pots moving freely and the continuity reliable. Brought up the voltage on my lamp limited isolated supply but no movement on the meter. The 6X5GT works ok and the resistors are all within spec. My mistake was not checking the meter before starting. Removed and carefully removed the moving coil meter face plate to discover the mechanism is beyond repair (Many moons ago I used to calibrate and repair AVO 7 & 8 multimeters, so I recognise a lost cause).
This tester can be revived, but I need a replacement meter. No luck at the moment in the usual places. It occured to me that we on this forum probably all have a store of used removed parts for that rainy day. There may be a possibilty that one of you has one looking for a good home or knows where I may source one. (I hope this doesn’t break the ad rules).
I am hoping to get this to a good working condition and then add a couple of more modern bases for 9pin valves and start building an additional settings data chart by testing known good valves.
Hi, not a reply but an update. I obtained a working replacement meter from a well known auction site and the tube tester is now working well. I have added a 9 pin and 7 pin valve base and started testing some of the 1950’s 60’s valves I have to build an additional database. The very first one I tried was an EL84. On the shorts test it showed pin 2 the grid was shorted. I checked the datasheet and it did not appear to be connected to any other pins internally. So I tried a known good working valve from a Bush radio and that passed all tests and I now have guide settings for any subsequent EL84’s. I can update if a better valve is tested, but I believe the valve is very strong. This tester will only do shorts, noise and emmissions tests. Very pleased, it just needs a good clean to get rid of the funky cellar smell.
@dave1956 great to hear! I didn’t reply as I was no help on sourcing a meter. Seems like you are on the right track with it.
Radios + Tubes + Scopes + Cars= Nothing better!