Can any one help with a model number for this radio ,valve line up 6N8 ,6AN7 ,6N8 ,6N8 ,6M5. Thanks.

Rectifier?, photograph? Not enough information sorry.

Photos uploaded.

Possibly in the era of a 125 around 1951? Would be handy to know valve line up? probably two 6N8, 6AN7, 6M5 and rectifier 6X5. It will be distinguished from 5Y3, by having heaters wired pins 2 & 7, one of which may ground?

Watch the transformer; I have seen several of those with windings popping out the side. Do not touch them. Refer back if its happening?

Would be handy to know valve line up?

See post #1: "valve line up 6N8 ,6AN7 ,6N8 ,6N8 ,6M5"

It is a Model 140 or 140K.

"Models 140 & 140 K differ from one another in dial scale, baffle assembly and cursor assembly only."

"Electrically these receivers are almost identical with Model 125."

http://www.kevinchant.com/uploads/7/1/0/8/7108231/140140k.pdf

http://www.kevinchant.com/uploads/7/1/0/8/7108231/125.pdf

The Model 140 & 140K is basically a Model 125 chassis in a Model 124 case.

UPDATE: Going by the dial it is almost certainly a Model 140K.

Thank you to all especially Monochrome TV, I downloaded the info. for the 125 (a very nice copy) . The set is in original condition nothing appears to have been changed even the electro's have not been replaced the only exception to this is the 6X5 has been replaced with a diode , I will probably go back to the 6X5 .The radio is physically difficult to work with ,the dial and dial cord mechanism protrude so it can't be turned upside down or stood on its end ,I will have to construct a stand to be able to work with it. Thanks again.
regards john.

A couple of bits of wood screwed onto the sides (holes are there) and braced to stop them spreading, works wonders. No hammering with valves in.

Despite being designed (badly) for car radio, some of the early designs of them were seriously flawed & in Zenith radio's in particular proved seriously unreliable. The most common fault was a heater cathode short & that normally was the demise of the transformer. Based on comments on another large radio forum Zenith transformers were marginal & the US upping its mains voltage did not help matters.

Unless there was added series resistance, or a serious dropping of the first cap of a choke input filter; Neither of which seems to have happened, that will cause a surge greater than would happen with a 5Y3 as the diode is more efficient.

Why I point this out is that that "surge", on start, can be twice that of the running "B" voltage at the cathode (filament with 5Y3), before the heaters cause the heater valves to conduct & load it down That Solid State diode has the potential to destroy any cap on B+ that cannot handle that sort of voltage. As there is virtually no current flow "on surge", all of the "B" supply will get to that voltage.