6X5G

OR

6X5GT?

John

Can't go by the tube number alone. Internal construction is more important. Most consider X shaped plate construction being the best. No "G" style tubes have this construction but some "GT" are like older shoulder type tubes.

The safest is the "solid state" sub. Easily built.

Weren't the majority of 6x5 failures found in Zenith sets?
.. if so what would that seem to indicate?

There was a three page discussion (w/ pictures) of this topic in May/Jun. A search on "6X5" finds it just below this thread. Much Zenith and 6X5 bashing and defending. For those looking to keep there posting numbers up, I suggest you look there for ideas, then rehash here. Those looking for info should probably just go there.

Please excuse my ignorance ... but what is that?

... is that the number by the avatar that indicates total posts?

If so.. why would anyone want to "keep those numbers up"??

I don't get it?

Do you lose your membership or something if you don't post?.. or post frequently?

It indicates that Zenith used them in a way that caused them to have a high failure rate. The problem was with the sets that used two, one in each leg of the HV. One theory is that differences in warm up times allowed one tube section to be overloaded as the sets were coming up.

I have 60 year old HP stuff with good original ones.

RRM

Guess it depends on what you want to use the 6X5G or GT in.

Most of the complaints come from people who own or fix Zenith radios. Maybe that says more about Zenith than it does about the tubes. The 6X5 was not a high power rectifier, it was for situations where conventional filament type rectifiers could not be used. It was designed for car radios and other applications where it had to operate on heater supplies that had one side grounded. It cannot handle more than 70 mA, and one has to be very careful not to allow the voltage from the cathode to the heater to go negative, or the insulation between them will break down in short order.

But in applications where it is used below its maximum operating limits--including small table radios, test instruments, and various other devices, I've never really had any problems with the 6X5 or the 6X4, which is a repackaged miniature version. But like other tubes and components, deficiencies in the original design of the 6X5 were probably corrected over time, so if one had a choice, a later production GT tube would be preferable to an early G version.

True of dual 6X5 sets. I had one short out while on the bench, caught it just in time.

6X5 GT safer, but still a bummer if pushed to limits. Best replaced by a pair or diodes and a dropping resistor or bucking transisformer. Plenty of informtion nere, so will not repeat it.

I totally agree with Chris and the others that Zenith gave the 6X5 a bad name. I have a Zenith 7S529 and so far I've been lucky. 2 times in a year the set went dead. I checked the 6X5 and even though it still lit, it was brain dead. No reading on either plate. Now, the second tube did the same thing and it was a Raytheon that l was built like Fort Knox,X plates, brown base and all. I assume the cathode opened up in both tubes.
The radio still works with another tube, but is not used much. It seems more a Zenith issue. so in my opinion, no matter how the tube was built, its gonna tank in a Zenith.

Now, I have a Pentron recorder that uses a 6X5 that I am listening to now. It is the staggered 6X5 design. The recorder has a 6V6 output, and this tube has lasted for 50 years. So, I believe, that the tube is fine within it's ratings . If you note, there has never been many complaints about the 6X4 which is the minitiature version. I wonder why? Not used in Zenith?

John

A 6X5 in a Zenith will be always swapped out for a solid-state replacement. I have encountered too many fried transformers in Zeniths due to poor planning by Zenith. I have many other items of equipment with 6X5's installed and they work just fine. Zenith apparently used 6X5's with a narrow margin of power consumption which resulted in overloading of the transformers so I will always replace the original with a solid-state sub. I have restored more than one Zenith to it's original configuration with a solid-state plug-in over the years. I believe in restoring a circuit to it's original state so it will match the schematic and will notate the schematic I pass on with the radio to reflect the substitution.