g0ozs

An afterthought on air over oil vs. Vacuum is that the air system can store enough pressure for several applications of the brakes for an extended period even with the engine off - I wonder if that's why it was used ? Iain

Hi All The folks at SHAS are having another event on 16th October at the old US radio station on Foxhall Heath near Ipswich and I will be bringing the SUMB - details on their web site (google for Suffolk aviation heritage should find it). Hope to see some of you there ... Iain

Hi I have a SUMB with the original air over oil system working and the brakes apply viciously when the air assist is activated so it isn't a design fault. A couple of checks I would suggest based on how mine behaves are: 1) the pressure gauge should reach 9 or 10 and the warning light go out after about a minute from starting the engine 2) the air cylinders should hold pressure up to 8-9 on the gauge after a week or more 3) if there is pressure you should hear a loud hiss for 8 to 10 presses of the brake after the engine is stopped 4) there are pressure valves under each cylinder which should operate after the engine has been running for a few minutes and if you disturb the pin sticking out of the bottom air should be released even after weeks As far as I can recall at this time in the morning away from the manuals the air supply is from a belt driven compressor so if none of the above is true I'd look either for insufficient belt tension or a faulty compressor - it should be possible to put a pressure gauge on the output given some rubber hose and jubilee clips as final proof one way or the other ... If the air pressure is good then it's likely the air operated cylinder not working - what should happen is that the hydraulic cylinder works alone until it travels around 1/3 of the way under manual pressure then opens an air valve to trigger the air operated cylinder at the back of the air pack which pushes it the rest of the way. Dismantling and cleaning all of the assembly at the back of the air pack would be a first suggestion in that case. You can find the full service manual MAT4155 on line as individual jpeg scans of pages with a little help from google and http://www.tm-ww2.com sold me a PDF version last year As to why air over oil seemed a good idea at the time rather than vacuum assist or full air brakes I am not sure - no doubt people who were involved in motor vehicles in the late 50s can comment ... Hope this helps Iain

Hi Jamie Welcome to the Forum. It's good to see a few more owners of French vehicles on here (I have a Petrol SUMB). Hopefully eventually there will be enough posts related to these vehicles to justify their own topic alongside the German, American and East European vehicles. Iain

I have posted my photos of the event at: http://www.g0ozs.org/marmon/SUMB-2011-07-web/index.html Many thanks to Colin Durrant and the rest of the SHAS team for inviting me and for all all their hard work arranging a great event and good weather! I think I counted 4 jeeps, 3 landrovers, a WC62 and a Bedford MW beside my SUMB. There are more details of the site and event at: http://www.suffolkaviationheritage.org.uk/ Iain

Apologies that should have been http://www.aceshells.com Iain

My main servers are hosted by http://www.aceshells.co.uk at £12/month for a linux virtual server with 10GBytes of storage. I also have a static website hosted by BT Business for £5 + VAT per month for a 5GB and a .com or .org domain name. Aceshells support and online admin tools are way better but if you need only a simple static website with no scripts or database and disregard the confusing sign up emails and use commonsense and the online help instead BT is ok and cheap. Regards Iain

Dear All I am posting this on behalf of an amateur radio friend who is a volunteer at the display centre but who is not a forum member. I will be there with the Felixstowe and District ARS and appropriate ex-military radio kit, and It is also likely to be the first event at which my SUMB radio truck makes an appearance ! Please send all detailed inquiries to Colin Durrant at the address below. Iain ~~~~~~~~~~~~~~~~~~~~~~~~~~~ Military Heritage Weekend at the Suffolk Aviation Heritage Display Centre The old Communication Station Foxhall Road Ipswich 30th-31st July 2011 Public Admission 11am to 5pm both days Participants Admission from 7.30am Site info: http://www.suffolkaviationheritage.org.uk/ The event is hosted on an easily accessible 1.5 acre site on Foxhall Road just off the A12 (N) east of Ipswich is expected to include military vehicles, re-enactors, exhibitions by local military museums, aviation art stalls, refreshments and overnight camping. Public admission - Adults £2.50 OAP £1 Children (U16) 50p All proceeds towards the continued development and aims of the display centre Vehicle exhibitors are welcome and registration forms can be obtained by sending me a PM or by writing to: Colin Durrant, Suffolk Aviation Heritage Group, 101 Avondale Road, Ipswich, Suffolk, IP3 9LA

Hi Again I checked my 353 and the meter should read when the test switch is moved to the check 28V position and a supply is present, even if the power switch is at OFF. The original field test kit was a metal box with a plate on top to which the insides of the 353 were attached and multiple plugs from the tester to the insides connected. I have one but it has broken connectors so is on the "to repair when I get round to it and find a donor 353 for the plugs" list and not immediately useful. The base test set was I believe an early computerised automatic tester driven by paper tape, which was the donor for the Thorn 48V 50A bench power supplies that M&B Radio used to sell on e-Bay. So I think it is a case of open up, keep one hand in pocket, and trace the supply through the set with a meter to find the fault. I would suggest checking supply polarity first as the diode would then prevent a reading, if I read the document I sent the link for earlier correctly. Regards Iain

Hi I have never found a circuit diagram - the best technical description I have found free is: http://ferret-afv.org/manuals/clansman_vrc353_description.pdf Looking at that document para127 on page 44 of the pdf is the PSU description. It would appear that the meter should be connected when the radio is in 24V test position even if the set is otherwise off. Protection is electronic by a diode and relay for supply reversal (so supply is only connected to the electronics if it is right way round) and overvoltage protection is electronic. No fuse is mentioned. I have copied the relevant paragraphs below. Summary is that the symptoms are consistent with a relay fault, blown diode, or thermal cutout fault. I will for my own sanity check that the meter reads with the set off when I am near my 353 later. Regards Iain 73 de G0OZS 127. The power supply unit is fundamentally a DC to DC converter controlled by a square wave switching regulator. Control loops operate on the regulator and converter to ensure adequate overload and over-voltage protection. 128. The voltage supply to the equipment, +24V nominaly is applied at (1a)PLI from where it is passed via supply filter (le) to Meter Control Board (lb). The negative is also routed directIy to (7g)X2 and the positive line to (1a)RLAl. 129. The Meter Control Board (lb) has a resistive network incorporating variable component (1b)R I which enables the front panel test meter (1a)ME 1 to be centred when the input voltage is at +24V d.c. (TEST switch 54 to 28V supply). 130. The positive line connnection into (lb) is routed via (1b)Dl to Power Relay RLA. In the event of a reverse polarity supply connection into (lb), D l prevents (1a)RLA from energising. The negative supply to ( 1a)RLA is routed via (1a)THT (closed for temperatures LT 85 C) and wafer AF of POWER Switch 53. (1a)RLA will energise for correct polarity supplies in the range 21-33V d.c. at all temperatures below 85 C when S3 is in any position except OFF. With (1a)RLA energised, contact RLAl connects the positive polarity input line to (7g)Xl. Both input lines are isolated from the chassis.

Hi The radio links for Ptarmigan were called Triffid - see: http://www.armedforces.co.uk/army/listings/l0085.html#TRIFFID Trifid UK/TRTC-471 itself was a Siemens product adapted for UK use by Marconis: http://www.armyradio.co.uk/arsc/customer/product.php?productid=1517&cat=0&page=8 http://adsabs.harvard.edu/abs/1981mimi.proc..129D http://www.ekmpowershop5.com/ekmps/shops/greenmachines/uktrc-471-triffid-radio-station-illustrated-parts-list-1133-p.asp Band I was 225-400MHz, Band II was 610-690MHz and Band III was 1350 to 1850MHz. So the antennas dont seem like a good match to either the 70cm (430-440MHz), 23cm (1.3GHz) or 13cm (2.4GHz) amateur bands Hope this helps Iain

David I think when used as a radiating element rather than to support an elevated antenna, there was a (ceramic?) base insulator for the 27 foot Larkspur mast - I'm sure that you could make one from rubber or plastic now . In that case you attach the 320 antenna terminal by a short wire to the bottom of the mast and the 320 earth terminal to a counterpoise wire laid out on the ground. In its original Larkspur role the 27 foot mast was used with a remote antenna tuner at the bottom of the mast (with a counterpoise or ground spike) and there was a coaxial lead from the tuner to the transmitter. Using the Larkspur tuners with Clansman radios is not ideal because the Larkspur sets used 75 ohm coaxial cables and "Burndept" connectors whereas Clansman uses 50 ohm and BNC. You could use a Clansman RT321 tuner (TURF 25W) in a similar way with the 320. The downside is that you need two operators (one to key the radio and one to tune) or a lot of running back and forwards once they are separated, since the 321 tuner is manually operated. It is notable that the slightly later RT319 special forces manpack reverted to the Larkspur design of having a separate (automatic) tuner that could be separated from the radio so as to be at the bottom of the mast so I think it is a better idea than the sloping wire from mast head to radio. The modern commercial SGC automatic tuners work in a similar way to the RT319 auto tuner and are ideal for this kind of set up. I have an insulating base (a metal plate with a rubber lined cup for the bottom of the mast) for the 11M Racal telescopic mast which allows it to be used in the same way. The 5.4 metre fibreglass mast contemporary with the 320 could not be used as a radiating element itself so came with a wire antenna that stretched from the top of the mast down to the 320 for the same purpose, so a sloping wire tied off (but insulated from) the top of the 27 foot mast might well be a simpler alternative, again used with a counterpoise wire. Note that the 320 tuner is designed for use with short wires up to 1/4 wave or long wires around 3/4 wave at the frequency in use (based on the antenna cutting and tuning data plate on the back of the set) so some optimisation is possible by adjusting the length of the mast or sloping wire. D10 is OK for short connections but is steel cored for strength (so stiff) and has relatively few strands - I would usually use electrician's earth wire which is copper and so more flexible and less lossy. Regards Iain 73 de G0OZS

Hi Mogmaner You can find some info in: http://www.vmarsmanuals.co.uk/archive/3731_R109_Training_Notes_and_Diagrams.pdf and the R109 section of: http://www.vmarsmanuals.co.uk/archive/681_Notes_for_Radio_Mechanics_Part_3.pdf Hope this helps Iain 73 de G0OZS

Hi I have also noted the lack of a French vehicle section here - I am a Simca Marmon owner as in the first picture (the original V8 petrol version fitted for radio) and have most of the French language original documentation but would like to share experience of technical and MOT/licensing issues with other owners. See http://www.g0ozs.org/marmon/2010-11/index.html I'm hoping to end up with a radio configuration similar to the QR-MH-14 VHF link station (similar in concept to BAOR BRUIN stations in Bedford RL trucks at the time) pictured at http://materiels.trans.free.fr/FH/QRMH8-1.htm although the radios will be modern Amateur 2m/70cm VHF/UHF and Clansman HF, and the mast Clark rather than the originals which would not be compatible with much in use today. The present antenna fit with four stub masts is more like the original 1965 fit with VRC9 and VRC18 family radios of USA origin. Does anyone have a decent photo of the pioneer tools fitted on the left side between the wheels of the SUMB ? - I am trying to figure out what I need to buy and how it was attached at present. Regards Iain

Hi Tony Welcome to the forum ! Have you installed radio equipment in the M37 or the Jeep ? Iain 73 de G0OZS

Paul The options for charging the PRC349 batteries are either the universal (349, 350 and 320/351/352) battery charger tray for the IBMS or the 6-way slow charger plate used with a DCCU. For occasional use it's better (and likely cheaper) to get the 12 x AA battery cassette rather than the sealed ni-cad pack in my opinion, so normal AA cells can be used. Regards Iain

Alien I think for a vehicle intercom the IB2/IB3 and some CB2/CB3 boxes is the way to go. The 321, 251/2 and 353 have a limited intercom function between the headset/handset and remote terminals so a local operator (who can tune the set) can be paged by a remote user at the end of a long D10 phone wire. A number of the audio boxes intended for that kind of use also have support for intercom - in particular the remote combining unit and the Adapter Telegraph Radio (a RT321 sized box that sat beside the teleprinter). You could implement a limited intercom between Clansman headsets with a 351 and an RCU more cheaply than using harness if you want a VHF radio anyway (and it has the advantage of not needing 12-pin harness cables or a 24V supply if the 351 battery is adequate). I have read that it is also possible to use the D10 terminals on these sets as a star point for multiple remote handsets which will then be able to talk to each other and the radio operator, but I have not tried this myself. Regards Iain

Hi It's definitely a bigger 2-pin plug about twice the size of the usual 321/353/harness box power connector - I was lucky to get one with my 322. I believe someone I know in the West Midlands had a small stock of the plugs to fit the 322 last year at £35 each but has now sold out so I expect it will be necessary to figure out the right part number to order from Farnell - getting the body and pin size right is the easy bit, the keying is a whole other matter ! The connectors I have unfortunately have manufacturer's markings rather than NSNs but the info for what it's worth is: The free plug (PSU end) is marked TEE 05 270 13 50 PB 9501 and (taking the wide key as 12 o'clock) has narrow keys at 3, 4, 7 and 9 o'clock looking into the cable. The free socket (Amplifier end) is marked ?755 18 50 SC 1701 8525 and (taking the wide key as 12o'clock) has narrow keys at 4,5, 7 and 9 O'Clock. "?" represents characters too scuffed to read. Both have "Thorn" embossed in the rubber insert that surrounds the pins or sockets. Both connectors are 30mm diameter outside the locking ring, 24mm outside the fixed part of the body, and the pins or sockets are on 10mm spacing. I have the opposite problem at the moment - a 50A PSU with no connector to fit the output socket ! The obvious (if not quite proper) solution would appear to be to replace the connectors on the PSU and 322 amp with a gland and short cable terminated in a normal civillian DC power connector like the Anderson SB 50 amp which costs about £6 a pair and has a lot more metal in it than the pins on the 322 power plug. That cable seemed to cause a problem either for the amp or PSU with RF getting in the power lead though - I originally fitted a twin red & black power lead to my 322 power plug and found that the amp or PSU tripped out when keyed CW at full power - fitting a shielded twin power lead as in the original 50A PSU to 322 installation cured that instantly. So I think any replacement also has to be a shielded connector. Hope this helps Iain 73 de G0OZS PS if anyone is interested I have one working and one dead (trips RCD) Clansman 50A PSU left over from my last trip to Withams for sale with power leads but of course no output leads - please PM if interested.

Best wishes to everyone on the forum for a happy, safe and successful New Year Iain

Stone The No.31 bases are for use with the tubular 1 metre elements that screw end to end to make 2, 3 or 4 metre vehicle whips. Mine are in the shed and it is way too cold to go and look up their NSNs tonight. E-Bay item 300495998593 (which is not mine, and is not from a seller I have dealt with) has a photo. They aren't expensive - if you want a low profile solution best to use one section only. The optimum length (as a quarter wave) for VHF air band is somewhere between 50 and 75cm so you probably ought to cut it back to that if air band receive is your primary use. Regards Iain

Alien I'd be interested to know more about the masthead 20W adapter. The 20W amps I have seen were for the RT351 (taking 4W input to give 20W out) as in the finned middle section of this 352M Were you thinking of the EVHF "pineapple" antenna base ? I have had a look inside and it is purely a passive matching network to increase the bandwidth of the sleeve dipole screwed in to the top - it actually includes a resistive attenuator to improve the match at the expense of absorbing at least 20%-30% of the power which is probably why it is inadvisable to use it at 50 watts for long ! I have been told that they show up well on any kind of IR night vision kit when in use, too. See: http://www.g0ozs.org/clansman/EVHF/index.shtml Regards Iain

Alien I think the lower VHF band is now less of a concern to the DBP and its counterparts in other countries. The UK limit for full/advanced licenses is now 100W using CW or FM or 400W SSB on the 50-51MHz band and 100W on the 51-52MHz band - see: http://www.ofcom.org.uk/static/archive/ra/publication/ra_info/br68r11/br68.htm and German amateurs generally have higher limits on the bands they can use than we do. Having said that the 50-52MHz frequencies were only released to amateurs in Europe after most continental Band I TV services closed in the 1980s so it would probably have been more of a concern until then. Regards Iain 73 de G0OZS

Stone The connector at the bottom of the cylindrical part of the VHF base is a BNC. I had a look inside one of mine a few months ago and all it contains is a small transformer with the input side connected between the BNC centre and ground (the metal body of the antenna base which is electrically connected to the vehicle body), and the output side connected between the whip socket lead and ground. The upper frequency will be determined by the performance of the transformer - I would have thought FM from 88 to 108 MHz has a good chance of working given that the normal upper limit was 76 or 79.999MHz for the various Clansman VHF sets. Air band goes up to 140MHz so may be more of a stretch. If the transformer turns out to not work above 80MHz, the best thing is to remove the transformer and connect the flying lead from the antenna clamp directly to the BNC centre. This allows use of a resonant quarter wave antenna cut for the band in use - 75cm including the length of the flying lead for FM broadcast, 50cm for 2M amateur, and something in between for air band. You can always extend the whip with insulating material to 2M so it looks correct for the vehicle. The military operated over a much wider frequency range which is why they used a fixed length whip and the TUUAM antenna tuner. Regards Iain

Part 3 - use of D10 cable Most of the larger Clansman radios (RT349 and RT350 excepted) have the facility for remote operation over D10 field telephone twin wire out to a distance of 3KM or so. The RT320 requires an external interface box (CRL/R) and the other sets (321/2, 344, 351/2, and 353) all have a pair of terminal posts, a wire stripper and a mode switch. The mode switch has settings LOCAL - for use as a radio with directly connected headset REMOTE - for use as a radio controlled by a remote operator over D10 IC - for use as an intercom between the local headset and the remote operator over D10 CALL - sounds a tone in the remote audio equipment The remote operator may use either a telephone handset (a special remote version with insulation piercing terminals behind the microphone and a call button) or a remote combining unit (which allows use of 2 normal Clansman headsets to control either of 2 radios using a pair of D10 connections). The Adapter Telegraph Radio (ATR) can also be used as a remote interface box, and the Larkspur era loudspeaker gun control (which has a built in amplifier and 2-wire interface) can be used on receive only. Note that the polarity of the headset, RCU or ATR connections matters - the radio will squeal if they are reversed. I have read (but not tested) that it is actually possible to use the remote interface of the 321, 351 and 353 as a kind of crude telephone exchange by connecting multiple headsets to the same radio - in that case whichever handset has PTT pressed will be heard by the others. Hope this helps Iain 73 de G0OZS

(Part 2 after a coffee refill) Operating practices: Amateur radio procedure (such as it still exists - I must be becoming an old fogey ) is largely based on marine morse practice (since that is what was around to copy when amateur radio started before WW1) and that has been carried into voice operation. As such Amateur and Military VHF speech procedures are rather different. We are of course very different from military operators in that we talk mostly about our equipment and location, make general calls and tune around listening for other stations calling, tuning is one painful aspect of the Clansman sets that use dial switches for tuning. I generally find myself using a dial tuned receiver (Larkspur R210) to search on HF and then set the 321 to the same frequency to call back. Larkspur Radios: As with Clansman those sets that tune across an amateur band can be used in that band subject to power limits. These sets are based on 50KHz (No.2 versions) or 100KHz (original) for VHF so channel selection is more of an issue - the VHF B sets (B48 etc) should be low enough power for all licensees but the C sets are probably for intermediate and full licenses. I personally have no experience of operating the Larkspur VHF sets - but they are mostly fixed crystal controlled channels on the manpacks and continuous tuning (with a calibration aid) on the vehicle sets. The ultimate Larkspur reference is Louis Meulstee's site http://www.wftw.nl/larkspur/larkspur1.html On HF I know several amateurs using the C11 or C11(SSB) which produce a fine AM signal on the 80 metre (3.5-3.8MHz band) - the original valve C11 is quite reliable, but the C11 SSB (very early transistors) really needs a repair workshop in tow! I have the associated R210 receiver and can recommend it. RF Burns: These are deep under-the-skin burns due to RF heating - they require a lot of power (50 watts plus) and contact with a very badly set up antenna system or the vehicle attached to it. You wont get one of a Foundation license power set - and even a RT321/322 at 300 watts is safe using balanced (dipole) antennas. Great care as to earthing is required when using high power sets with a whip antenna and the vehicle as ground, however. the only times I have had burns is when an earth connection was broken and the microphone lead became live at RF since it was acting as a counterpoise (artificial earth) wire. Hope this helps Iain 73 de G0OZS