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From memory I think the 352 and 320 on transmit are more like 4 amps. I remember a chap in Wales did list mains power supply units built into a 1AH battery case on e-bay a couple of years ago but I havent seen them since. The problem with the 351/2 and 320 is that they were never designed for noisy supplies - in a vehicle the normal approach was to float charge a battery off a DCCU (which is a switch mode supply but rather well made and expensive). So direct connection to a 24 v vehicle supply or a simple switch mode type would be unwise. I think the larger 4AH cases would be adequate for a linear 24V 4A supply if adequately ventilated, but you might struggle to find one ready made and new today. The alternative which I know quite a few people have done with dead Ni-Cd packs is to fill them with a pair of small 12V Yuasa sealed lead acid batteries that can then be float charged from a cheap "mobility battery" charger without too much trouble. Even with periodic replacement of the lead acid cells this is likely to be cheaper than a DCCU and fresh Ni-Cads. From experience it's best to get the metal cased type as opening them by carefully drilling out the rivets is much easier than plastic. The actual metal is surprisingly soft and relies on the batteries and foam packing for strength when assembled. You will probably need to line it with something stronger if you plan on building anything inside. Hope this helps Iain 73 de G0OZS

Tony FCS1362 (formerly MPT1362) which is the standard for mobile radio (PMR) installations mentions the risk in section 3.4.4 but gives no recommended limit. See: http://www.fcs.org.uk/my%20files/fcs_pdfs/codesofpractice/08-05-12%20fcs%201362%20final.pdf I am sure I looked into this when I had the SUMB with vertical antennas (given that I live near a mainline level crossing between me and the nearest petrol station) and found that the lowest limit is for level crossings on electrified railway lines and is around 5 metres but I can't now find the reference on line. The HSE advice for agricultural work near overhead power lines at http://www.hse.gov.uk/pubns/ais8.pdf gives a minimum height of 5.2m for such lines in the UK over fields and 5.8m over roads and recommends that vehicles higher than 4m / 12 feet are not used near such lines. National grid give advice for higher voltage lines in ENA 43-8 which is summarised at: http://www.nationalgrid.com/uk/LandandDevelopment/DDC/devnearohl_final/appendixIII/appIII-part2/ and downloadable from: http://infrastructure.planningportal.gov.uk/wp-content/ipc/uploads/projects/TR040005/2.%20Post-Submission/Section%20127%20Application/130402_TR040005_WPD_Addendum_Appendix_9.PDF Note 2 to table 6.1 in the last referenced link explicitly states that the 5.8m clearance is intended to permit vehicles up to 5m in height to pass under conductors at up to 33KV. This is 0.8m separation between wires and top of vehicle. Given that antennas with pointed ends will cause higher electric field strengths (and more chance of a spark) than a vehicle roof I would be inclined to add some more safety margin and 4m from ground to tip of antenna is probably more sensible (and aligns with reported state laws on mobile antennas in the USA, I believe) Regards Iain

I think there must have been a show fairly locally to Ipswich & Colchester - I followed 2 very nice jeeps up the A137 from Brantham to the A14 at about 8.30am today and saw another coming on to the A12 at the Martlesham Black Tiles roundabout a few minutes later - this afternoon I passed a convoy of 2 x CCKW and several Dodge WC trucks going north on the A14 as well. I wonder if anyone knows what I missed so I can put it in next year's diary? Iain

Arjan The EMERs (repair instructions) are available from the Wireless Set No. 19 group at http://www.royalsignals.org.uk/testgear.html - at a guess its purpose can be deduced without retrieving them as "TMS" is likely Telegraph Measuring Set. One of the curators of the WS No. 19 archive is a member here and may be able to confirm or deny my guess ! The documents are dated 1947 so probably just post-war manufacture. Regards Iain

Phoenix Technical Services Norfolk (PTS Norfolk) trading as gten98 on eBay also holds stock and lists them from time to time - worth sending them a question if none are currently listed Iain

Hi Having had a V8 SUMB my problems were all with fuel supply to the engine rather than electrics. I'd check that the fuel pump is lifting fuel from the tank and the pipe is full all the way to the carburettor - easily tested by disconnecting the pipe to the carburettor and cycling the pump manually to see if fuel comes out - otherwise it will fire and run for a short while on what's left in the carburettor and then stop. There's a lever facing forward and down at the bottom of the fuel pump that needed 50-100 cycles to charge the system on mine before attempting to start after a few weeks standing. I have most of the manuals in PDF if you need anything PM me. Regards Iain

A reasonably successful factory conversion was the Simca SUMB upgrade from Ford V8 to turbo diesel by Renault - around 1000 of the then 30 year old vehicles were refurbished with the same turbo diesel engine as the TRM2000 (along with new electrics and brakes) in the early 1990s. The motive in that case was fuel economy and spares rationalisation, although there was a small increase in power (110 to 130HP from memory). I am also aware of some unofficial conversions - at least one UK owner used a Ford transit diesel engine and gearbox coupled to the existing transfer box. Iain

Paul Indeed an interesting item - the prehistoric anscestor of the modern scope/meter hybrids. The low DC Volts reading I now understand - the set zero on the meter movement is loose and ineffective I have some other similar meters to use as an exchange so that ought not to delay me very much - I note in passing that the meter scale has a 1959 date so the instrument is no earlier than that. I may actually get the original movement fixed (a the father of a colleague at work was a watchmaker and has done similar repairs for me before). The input test lead plugs are basically the same mechanically as a lot of small DC power plugs so I should be able to find something that fits & can be used with the outside left unconnected. That will be enough to get it going as a bench multimeter at least Regards Iain

Photos as promised (Tapatalk Willing!)

Thanks Caddy for the invite to pick this up ! We got it home safe (with my arm a few mm longer after carrying it the length of Duxford) and it powered up and even gave a scope trace 2/3 of the screen wide with no smoke or sparks ! It is definitely the worse for component ageing but I think it will be successfully revived once I get a circuit diagram. The bottom half is a Simple multimeter that works without mains power and reads about 12% low at the moment (so a good 1.5v battery reads 1.3v) - the top half is a single channel oscilloscope and still gives a trace and is even picking up electrical noise when one end of the Y input test lead is floating. The sweep is only 1/2 the width of the screen so I suspect there is an x amplifier problem though ;( Based on the components inside I would revise my age estimate earlier to late 1950s or early 1960s Now to find a circuit and more of the 10H/260B insulated test leads - I think the strange type was chosen so a lead with the probe attached to a high voltage circuit under test was safe if the instrument end is loose on the bench unlike most modern ones! A circuit needs to be found too ... I will try and post the internal pics I took when I got home - expect an update in a few months! Iain 73 de G0OZS

Hi To do continuity tests you need one each of the test adapter 5124 and the shorting adapter 5125 thus Tester - 12 pin cable - 5124 - cable under test - 5125 The tester connects pin 1 via the shorting adapter to each of the other conductors in the cable under test lighting the green lamp if there is continuity. As I understand it (and I have a 5125 in the post to find out) to do short circuit tests remove the shorting adapter 5125 from the end of the cable under test and turn the switch to each position in turn - if there is a short to another conductor the red lamp will light Hope this helps! Iain

Caddy I am probably close enough to pick it up (near Colchester) - I would be happy to try & get it working again. I could do with a replacement bench meter anyway even if only that part is ok - PM if you want to discuss further. Regards Iain

I've been playing with and building radios as a short wave listener since the mid 1970s and worked professionally in Electronics during the 1980s when Clansman sets were then the latest and greatest and are very much the kind of technology I used to work with in college and my first day job. Having waited 35 years or so they are now available as surplus and finding out about the insides over the last 4 or 5 years has been a great deal of fun - some are very much as I guessed when I first saw them in the 1980s and others are surprisingly mechanical (especially the 321 and 353). It helps that VMARS (the Vintage & Military Amateur Radio Society) obtained most of the military service manuals under a FOI request in 2010 and they are available to members from the Society archive - a few other manuals have escaped onto the open internet as well so Google has been most helpful ! As I get older and my eyesight gets worse I seem to be going further back in time to when components were bigger than rice grains so Larkspur radios next I think Regards Iain

Timbo I have been involved in wireless since school days in the 1970s when radio shops, the small ads in "Practical Wireless", and radio club junk sales were still full of interesting stuff of this and earlier vintage. There isnt much to do with 1950s and 1960s radio that I havent seen (and havent wasted pocket money on :nut: ) Having seen the front panel it looks more useful than a waveform monitor - more like a combined test meter and low spec oscilloscope - I suspect a lot of technicians and Radio Amateurs would have gladly traded an AVO for it in the 1950s ! Regards Iain

Any chance of a front panel photo - and any information as to where or what it came from? The style of the label looks 1960s or early 1970s prior to GEC taking over Marconi. I'd guess based on very little info that it is a waveform monitor used to check modulation on an HF radio transmitter - this is effectively a simple oscilloscope. Regards Iain

Looking at the ISO group NSN database I suspect I need 6625-99-622-5125 "Adapter Test Shorting" - if anyone has one I would be grateful to see a photo !

It should be clearer with a few more photos ... As an aside does anyone else have one of these - I am suspicious that I should have had 2 different breakout boxes with male & female of the 2 pin power and some other connectors rather than 2 of NSN 6625-99-622-5124 and would be happy to swap with someone who has 2 of the other kind ? This one has 2 x Harness 12 pin, 1 x 10 pin CPU male socket, 1 x 7 pin male, socket, 1 x 7 pin female socket and 1 x 2 pin male power socket. Regards Iain 73 de G0OZS

As to what they are and do, the TUUAM (Tuner Unit Automatic Antenna matching) is an antenna tuner designed to match a 2 metre whip antenna (w x Clansman rods) and base No. 31 with the cylindrical VHF adapter to 50 ohm cable as used with Clansman. The ARFAT (Adapter Radio Frequency Antenna Tuning) connects between the UK/VRC-353 and TUUAM and contains a power attenuator to protect the TUUAM and radio from high levels of reflected power (bad SWR) during the time when the radio is keyed but the TUUAM is working to match the antenna after a frequency change. Quite why the ARFAT was necessary and not built into the 353 or TUUAM is one of the mysteries of Clansman - as I understand it the TUUAM is a RACAL device and used with the initiate box rather than the ARFAT as part of the 351/2 vehicle kit whereas the 353 is a more powerful vehicle mounted set by Marconi. In use with a 353 connect a BNC lead and 12 way "harness" cable from radio to ARFAT and a BNC lead and 7 way cable from the ARFAT to the TUUAM. The TUUAM output has a short BNC to the antenna base adapter which contains a transformer and must be used with the TUUAM. Iain 73 de G0OZS

Hi I have one of these. There is a breakout box with 2 of each connector that connects to the 12 pin connector to enable almost all combinations to be tested. I'll try to do a couple of pics tomorrow if it quits raining and I can do it in daylight. As with the coax tester it is powered from a radio via a 7 pin cable. Regards Iain 73 de G0OZS

Hawky, cornishbloke Happy to do you a CD each. The masts share most of the components and the method of construction - the main differences are longer tubes and an extra guy attachment point on the 12m Regards Iain

Hi The ones I have are the EMERS for repair rather than the user guide - PM me with where to post it if you still need one and I will look at burning it on a CD-ROM for you- if you can donate the value of the stamp to a poppy tin come November I'll be happy Regards Iain

In terms of pre-ww2 Radar developments around the world the IEE conference publication "Radar Development to 1945" 2nd Edition 1989 ISBN-13: 978-0863411397 is highly recommended. This had papers by surviving pioneers and modern historians about pre 1945 developments in the major countries prior to WW2 - the work documented in my 1st edition pushes the beginnings of VHF radar in the UK and Germany back to 1934/35 although with rather different motivations - as a naval gunnery rangefinder in Germany and as air raid warning in the UK. US air warning development seems to have started a year or so later. The unique British contribution was the Cavity Magnetron developed at the University of Birmingham that allowed use of high power at progressively higher microwave frequencies to escape jamming and improve accuracy as the war progressed. Having said that (and returning slightly to topic) the early long wavelength Chain Home at 30 MHz/10 Metres was much better at detecting some "wood and wire" aircraft that would have had almost no reflecting area as seen by a 10cm or 3cm microwave radar but did have wires of comparable length to the radar wavelength that would re-radiate the signal - probably the Ho. 229 would have been in the same category if engines and control wires were the only large (or more importantly, long) pieces of metal. VHF radar remains one of the best counters to 1st generation stealth technology to this day Regards Iain

Diagrams from a manual or EMER related to focussing of optical equipment ?

Mike The pioneer rack looks like the one on my SUMB and a British shovel fitted that, if it helps ? Can you get a closer photo of the label on the ATU - I know a couple of people in France who may be able to help with data given that Regards Iain

Dave The voltage will be determined by the PSU regulation and battery charge current - my experience of the 50A PSU is that the variation between full load and no load voltage is minimal and most examples are set at 28v. You may find that some kind of charging regulator (or at least current limiter) is desirable if the batteries ever end up deeply discharged as the PSU will trip if its output exceeds 50A by much. Regards Iain 73 de G0OZS