I was afraid you would say that. I have no experience with MEN regulations, but I can appreciate why we have them.

I will not run this equipment again until I source a 1:1 tranny for it.

Thank you,

G.

I am a moderator on the American site & it is fascinating to see the number of hot chassis sets. There are two types. One where mains could be on the chassis as they had two pin plugs that could be reversed and a later generation that where the mains was floated.

This of course did not stop them, from placing an RF bypass cap from Neutral to chassis, which often became active to chassis. To help in population control they also ran a cap & often resistor as well from the floating chassis to mains.

There is one post currently running, where a cap is used in a battery eliminator type PSU to go from Neutral to "C" on the set. Two wire mains cable no earth wire. The set has hum when the plug is in a certain position. and earthed. Clearly when you have active on that line cap; earthing the set completes a circuit: Active through cap, through radio to ground. as there is the full potential of the mains across the line cap.

Don't think your safe here. Someone, or several, were asleep at the wheel when some test equipment got in here: I have seen several metal cased bits of test gear & apparatus (with transformers) in metal cases with a cap, mains to cabinet & chassis: Not clever. Most of these are not proper line caps (X / Y) and are a death trap, as far as I am concerned

I can second Marcc about certain test gear and mains capacitors. I was vetting a large bench supply design from over there in asia with transformer (good) and then could not believe my eyes to see the mains cord green wire "earthed" not by connecting to the chassis direct but to the nearest negative output track on the control PCB. At some other point of the PCB track a thin green wire then connected to a chassis soldered earth point!! Worse still they had a pair of GREENCAPS one from active in and one from neutral connected to another point on the PCB track. What could possibly go wrong?!!!!!! This arrangement probably gave them the required hum/hash/ripple levels but safety went out the window!!!!
My solution was to wire the mains cable direct to chassis, the little wire then "grounded" the PCB assembly and the greencaps were tossed and proper mains rated 250VAC caps wired from the fused side of active and neutral to the case earth point and to hell with noise level created.
Fred.

We, have actually tightened up regulations here as far as plugs & sockets go & introduced a testing regime. Domestic wiring falls into the category of a protected trade, where who wires what is covered by legislation. Electricians here do have to issue a certificate of electrical safety for there work.

Technically, if I fit a new power cable to a radio, which is a commercial fix; I am obliged to test it per regulations. Its a pretty common occurrence here as I get several with power cables that are just plain scary. The place here was originally wired in the early sixties & was recently upgraded with the exception of the house. I allowed around 1K to modify & fix things & bring them into compliance on my side of the fuse boxes (1 distributor 5 subs): Fascinating the dodgy stuff a couple of "electricians" had done (100% inspection of all wiring).

One would note among the many an LSG-10 clearly showing on the circuit, caps line to ungrounded chassis and Heathkit IT-22 and an Honor (Laffayette) TE-46, RC bridge (all with transformers, 2 wire cables and metal cases ) same deal.

Modifications done: Not having that.

If the chassis is connected to Neutral and then Earthed it will trip the RCD (if the house has one). If the mains wiring feeding the unit is reversed then you have Active shorted to Earth!! and a blue flash just before the breaker trips.

Irext you're correct. I have an early 1930's console which is AC/DC and the chassis is wired to the neutral. It had a bayonet fitting on it when I

got it, but I wired a plug and used my multi-meter to make sure I had it wired correctly with the chassis neutral and not live. The ground wire

and aerial both have a .005μF cap in series and if I remove this on the ground the RCD trips so I have left them as is, as the ground is just for

the antenna circuit integrity, it's a good set, but must only be used in a plug I've tested beforehand for correct polarity, something I've done to

the plugs in my home as I was nearly electrocuted as a kid when I stuck my finger in a bedlamp socket which was switched off and burn't the

end of my left index finger off. The earthed shade completed the circuit with my hand, quite shocking at the time so I have much respect for

electricity and like to eliminate the chance of any surprises!

If I remember correctly those bayonet fittings were ambidextrous which means the chassis could be active or neutral depending on how you plugged them in. The radio would still work but don't touch anything while switched on. Always make sure the knobs are are on their spindles as they can be live . Hence it was illegal to have on off switches on radios at the time so you had to turn them off at the light switch.

In earlier times here radios were plugged into light sockets. The US NEMA two pin plug can be reversed. Their wiring seems not to be a s regulated as much a s ours

Well in the US, where we have A and N, they have what I think they call L1 and L2. The voltages are balanced about ground by the pole transformer out in the street. So max RMS to ground is 55 volts. A lot safer, not so much need for regulation.

Our friends in the US will correct me if I'm wrong.

With either a bayonet plug or 3 pin plug the manufacturers were able to fit double pole power switches but generally chose not to in order to keep costs down. Upmarket radios had them as standard but the radio for Joe average didn't unless it was fitted as an after-market accessory.