fv1609

Have you got a picture of the exchange can't find a 6/7 line one. I have EMERs on exchanges with lines: 25 16 40/160 5 9 100/150 48/64

Pete I hadn't actually thought about an equilibrium of metal transfer. But I suppose it must be so, when arc welding I assume that all the metal from the rod does end up in the weld.

But Pete the rotor doesn't erode. It receives the metal lost from the pillar electrodes in the cap, so in a 4-cyl a quarter of the metal lost it is shared between the pillars. Each losing a quarter share of metal. If the HT was wired incorrectly to give a positive spark then all the loss would be from the rotor arm (not to mention the other issues with a positive spark)

Pete I had always assumed it was a minimum gap to allow for manufacturing tolerances plus a bit to allow for slight wear/minor misalignment of the rotor arm to avoid the risk of the arm ripping into the posts in the cap. Interesting to shave some metal off the rotor arm & see if that did the job of a "spark enhancer".

Ah I've certainly got pictures of one, not sure that I knew there was another.

Yes it does work Pete but not with a metal button as that would just be a short circuit. Here is my effort some years ago. This the basis of the spark enhancers that are basically two self tapping screws with a head to head gap. I don't know what effect it would have to increase the gap for the rotor arm, would it be similar?

Pete thank you for that it makes an interesting read. It is written in sensible English by a bloke who has thought things through & sought to investigate things for himself, which is excellent. He writes: "Once the plug fires the resistance comes into being. The coil cannot get rid of its energy in the shortest possible time due to the resistance. This reduces current flow in the spark and it takes quite a bit longer until the energy in the coil has expelled itself via resistor and spark gap. This results in a longer spark. However the spark is weaker due to energy loss in the resistor." Yes that is the whole point! To reduce the erosion at the plug gap, we all know that the higher the current of a welder the greater will be the loss of metal from welding rod. That of course is why the designers & manufacturers incorporate resistance in ignition systems.

Sorry it was at Otterburn

Any of the Commer APC?

Pete there are two purposes for incorporating resistance in the secondary circuit. To reduce erosion at the gap (& the distributor cap). This is said to be in the order of 1,000 - 4,000 ohms, but is not sufficient to reduce RFI. To suppress RFI 10,000 - 20,000 ohms is needed. Driver Training (All Arms) Vol II "Contrary to popular belief held in some quarters, they [resistors] do not affect the performance of an engine in any way. In fact, in some engines, they improve the cold starting" I did some experiments to measure the current flowing through the secondary circuit & found it to be very low. I think the introduction of 10,000 ohms only reduced the HT by 7 volts. The thing to bear in mind with the voltage for the primary circuit, provided the battery is fully charged, that this voltage is just to build up the magnetic field so it can collapse & produce a back EMF to be stepped up by the coil secondary winding. The equivalent 12v coil the HT output would be of similar strength. Admittedly a load from the starter motor will reduce the energising voltage a bit but it is not necessary for the coil to be 100% saturated with magnetism to give a satisfactory output. Have you still got the reference to that article?

The "New Code" is the 1967 code, oddly I can't find a code for Shermans in the 1955 system in my 1963 list.

Excellent info, you go to work early

Yes (although strictly speaking it would be 56 in BS 381, it became 356 in 1948 with the introduction of BS 381C)

Indeed, I should have re-read my own posts on this old thread that was I trying to find earlier http://hmvf.co.uk/forumvb/showthread.php?49270-RAF-UIN-Unit-Idenification-Numbers&highlight=Joint+Supply+Chain+Services

Oh right. Just misled by JSCS, thinking the CS bit might have been the same as in SVCS. Richard, you & that Mr Google

Excellent stuff, well I would never have got that one. What is your take on SVCS?

Sounds plausible Richard that seems rather large for an abbreviation. In official lists of abbreviations, anything that has Services in it is just represented with "S". The other thing is that CS is now common to other places eg CVD Ashchurch is now JSCS Ashchurch. Which might be something like Joint Service Close/Combat Support? I thought there was an old thread along these lines, but I've not been able to find it.

If you roll the shutter for the map light down it should switch off. I rewired mine so that it only worked with the ignition on & it is easy for it to get left on & not notice this on a sunny day like today. The problem with the fuse ratings is that the figures quoted on the lid are for the holding current not the blow current. So it is easy to end up with fuses that blow only too easy as they are about half the value of the blow current.

A 1963 list has 11 Churchills they are all RE types but have 1955 Asset Codes structure.

In the 1967 lists no Churchills listed, of course lots of Centurions, some Conquerors, a few Comets, a few Chieftains & a couple of Sherman ARVs.

Chris I have quite a number of listings of MOD abbreviations & acronyms but none give a straight answer. So piece by piece dissection is the only way until someone can give a straight answer. There are one or two on here who work in that line who may help out. In the meantime might I suggest: LOG - Logistics SVCS- SV often is Support Vehicle & must be referring to a type of depot in that there is also SVCS for example: DEP SVCS THATHAM SUB DEPOT JT SVCS INTERROGATION ORG HQ ARMY MED SVCS TA RAMC TRG GP CS - often means Combat Support NESBS no idea but obviously the location of the depot MAT PK (V) - Materiel Park (as in TA)

So Chris I assume the UIN is A6205K

I seem to remember we have talked Asset Codes before, not something that interests that many people. Are you building up a database or similar?

Here you go: