Marconi Test Equipment Mains Leads.

[David Simpson]

There seems to be a school of thought who believe that mains equipment displayed &/or sold at BVWS Swapmeets must have their 3 pin mains plugs removed. However, as folk who are familiar with Marconi Test equipment, & Sig Gens in particular, know that the mains leads(rare as rocking horse manure) are often of a very small diameter & jolly awkward to replace due to the small grommets & P clips which Marconi used.
I'm working on a 995A/5 for a Forum chum who'd bought it at a Swapmeet last year & the mains lead had been brutally severed close to the cabinet. Surely, anyone who is active in the vintage fraternity must be able to, at least, be able to use a screwdriver to remove a plug - if required by a BVWS swapmeet official. Fair enough, if the lead is badly damaged, then obviously it needs replacing. But random snipperty snip with a pair of pliers is a no-no in my book.

Regards, David

[barrymagrec]

Any piece of equipment that has had the mains lead cut off needs to be valued as scrap. Along the same lines as equipment advertised with the old "believed working but cannot test as mains lead is missing" refrain frequently used for kit using the old style Bulgin connector.

[FIXITNOW]

local auction house here does the same if hard wired snip it off, if plug in take lead and throw it away ,then sell as collectable for display only. can be a real pain for some of the hard to find types

[turretslug]

I agree that it's basically speed/laziness that guides folk who do this and have encountered the "Marconi problem", (notably thin mains leads) too. In fact, I specifically look out for pieces of 3-core 0.5mm. sq. mains lead for this reason- not quite rare yet, but far less common than 0.75mm. Though even 0.5mm sq. is usually thicker than the original Marconi flex. As someone who dislikes captive mains leads anyway, one (slightly inelegant) solution could be to fit an IEC C14 line plug to a stub of cable- but this assumes that scissor-man has left 10cm or so on the equipment.

[Refugee]

If I want to stop something being plugged in I will make sure it is difficult to plug the item in.
If a bit of equipment had broken and I do not have time to get it sent away to be fixed I will make sure there is a warning and at least a bag tied over the plug or better.

[Station X]

That's fine where the user has common sense but, to use a cliché, common sense isn't very common these days.

[David Simpson]

Many thanks guys for all the helpful comments.
I suspect that most auction houses are bound by H & S regulations, and Insurance requirements. Most, if not all of their staff ken nothing about vintage radio & electronics. However, BVWS,( & VMARS, ARS, etc.,), auctions & sales are all, by definition, attended by supposedly knowledgeable sellers & purchasers. So hopefully word will get around about it only being fair to just remove plugs from hard wired items. If someone must weald a pair of pliers - then just an inch from the plug please.
Refugee's method of safely bagging removable mains leads is spot-on.
In general terms, some removable mains leads are becoming extremely rare. Solartron, AVO, Philips, & several other test equipment manufacturers used a variety of chassis mounted mains sockets.
Is there a definitive BVWS policy on 3 pin mains plugs, or does it depend on the venue building's owners ?
To digress slightly off-topic, how many other folk use a PAT tester after working on their own or someone else's test equipment( or radios & TV's etc. for that matter)?

Regards, David

[turretslug]

Not to mention that slim connector used on Telequipment scopes! It's often possible to fit an IEC C14 ("kettle"- though strictly speaking, kettles use the "hot" version profile) panel plug to old kit, though there seems to be a fundamental pre-emptive law of equipment design that when such connectors can be retro-fitted, they need to be located with sub-millimetre precision in both axes. Odd.

The main difference between PAT testing and old-style wisdom of 500V Megger on line-to-earth and low-ohm multimeter test of earth continuity (apart from an inflexible functionary with a roll of stickers) is that PAT assumes a significant and representative current, dependent on rating but 10A for the sort of stuff we use is sensible, to be passed round the earth loop for several seconds to check connection ruggedness whereas a multimeter only passes typically 10's of mA and doesn't really test earthing integrity under real-life fault conditions properly.

[Refugee]

If there is a loose earth connection PAT testers make it spark making the fault easy to find.
I have a PAT tester but do not always use it.

[murphymad]

BVWS policy on mains plugs and leads:

No equipment is to be sold at auction with a mains plug attached and available so that the prospective buyer or final buyer is able to plug the thing in at the venue to see if it works.

The reason for this is simple. We had a very nasty incident where something was plugged in at an event and it knocked out the main breaker on the hall which plunged us all into darkness (December RWB event some years back).
This happened in the middle of cashing up with many people still in the queue to pay.
The result was it took about 10 mins for the caretaker to contact someone to tell us where the main breaker was located as it was not in the same place as the fuse boxes.
We then had to wait for all of the computer stuff to reboot and get everything going again before we could continue.
It is not going to happen again!

I now always make a point of tucking in mains leads where possible and generally removing all plugs. Definitely those that do not meet current regulations as the BVWS could be liable under the current EU law.

Any really bad and crunchy cotton covered leads that have rotted away are cut off.

Plugs scratch cabinets and get caught up with other things (Murphy's Law).

We also get stuff from collections where they have previously bought from other auctions where the mains leads have already been cut off.

I know well that the Marconi equipment uses a very thin mains lead and I mostly leave it intact because it is unusual, unless it has been squashed or damaged and would be deemed to be in need of replacement.

Mike...

[David Simpson]

Many thanks to Mike for clarifying the BVWS position.

Regards, David