armouredfarmer Posted September 26, 2016 Share Posted September 26, 2016 Someone very kindly gave me two radio masts at the weekend, I assumed at first that they were 5.4 mt type but further inspection shows they very definitely aren't. Each mast consists of 8 fiberglass sections, 36 ins long (not including spigots), 3 pegs, a round metal base, a selection of stay lines, a halyard, 2 stay plates and a cleat all contained in a very neat canvas carrying case . Ring any bells with anyone? Ive googled various NSNs on components and got nothing more useful back than "mast section" and "stay" so frustrated in that direction. The fact that the sections are apparently an imperial length and the carrying case is canvas as opposed to plastic may mean it predates the clansman era. Pictures to follow when I have the opportunity. PT Quote Link to comment Share on other sites More sharing options...
g0ozs Posted September 26, 2016 Share Posted September 26, 2016 Hi I had a few of the sections at one time but never a complete mast kit - whatever it is goes back to the Larkspur era as I got them at a Leicester radio rally before 1990. If what you have is what I had, then they differ from the more recent RACAL ones in that the outside is fluted and the green is closer to NATO than olive, if I remember rightly. I don't think they are actually Larkspur because the 1950s Larkspur antennas were designed for the 27 foot telescopic steel mast - I think it is related to fixed link or electronic warfare / DF equipment from the late 1960s or early 1970s just before metrication - I have dim memories of seeing a picture in a manual for pre-Vampire DF kit. The big cousin of the 5.4m Clansman mast is the RACAL MA675 which has 8 x 1m fibre glass sections - it differs in that each set of guys has four ropes at 90 degree rather than 3 at 120 degrees. Regards Iain Quote Link to comment Share on other sites More sharing options...
armouredfarmer Posted September 27, 2016 Author Share Posted September 27, 2016 Thanks Ian, the outside of mine are not fluted but otherwise they sound similar, one thing that puzzles me is that both mast kits have the same stay sets but there are a strange mix of lengths so you only have two pairs of stays the same length in each mast. As promised, pictures Quote Link to comment Share on other sites More sharing options...
Chris Suslowicz Posted September 27, 2016 Share Posted September 27, 2016 Thanks Ian, the outside of mine are not fluted but otherwise they sound similar, one thing that puzzles me is that both mast kits have the same stay sets but there are a strange mix of lengths so you only have two pairs of stays the same length in each mast.As promised, pictures QUOTE] That looks remarkably like a scaled-down MA-675 mast in terms of the poles and carrying case, and the direct ancestor of the Clansman 5.4 metre mast from the general size of the beast. Trials model of the 5.4 metre mast (later simplified and lightened as a result of the trials)? That would be my guess. Chris. Quote Link to comment Share on other sites More sharing options...
mogmaner Posted September 27, 2016 Share Posted September 27, 2016 Racial ma675 9m mast Quote Link to comment Share on other sites More sharing options...
armouredfarmer Posted September 27, 2016 Author Share Posted September 27, 2016 Thanks Chris and Mogmaner, I don't think it is an MA675 as its not 9m tall however your suggestions have pointed me in the right dirrection as I see Racal list an MA1381, 7.3m, fiberglass mast which would equate to the 24' of this one. Now to find out what it was used for.... PT Quote Link to comment Share on other sites More sharing options...
armouredfarmer Posted September 27, 2016 Author Share Posted September 27, 2016 And indeed on close examination of a mast section I can see a faint MA1381 1 marked in black, thanks again chaps. Quote Link to comment Share on other sites More sharing options...
jarrett Posted September 27, 2016 Share Posted September 27, 2016 Larkspur,used with the a14 backpack plus you have the nsn visible in one of the pics! Quote Link to comment Share on other sites More sharing options...
armouredfarmer Posted September 28, 2016 Author Share Posted September 28, 2016 Larkspur,used with the a14 backpack plus you have the nsn visible in one of the pics! Yes Jarret, but that's the NSN for the bag unfortunately. Quote Link to comment Share on other sites More sharing options...
Chris Suslowicz Posted September 28, 2016 Share Posted September 28, 2016 Yes Jarret, but that's the NSN for the bag unfortunately. This is true, but the bag is custom made for the mast and if you're lucky plugging the NSN into Google will get you one of the 'parts' websites that give a cross-reference to the manufacturer and their product code. (I did this with my MA-675 9 metre mast to get most of the parts list). Once you've got that much information you can expand the search a bit. The canvas case points to it being Larkspur, and stayplate with an extra hole for a halyard points to HF, so the SR A14 (aka BCC 30) is a very likely candidate. A look in the user handbook should confirm that. Chris. Quote Link to comment Share on other sites More sharing options...
armouredfarmer Posted September 28, 2016 Author Share Posted September 28, 2016 This is true, but the bag is custom made for the mast and if you're lucky plugging the NSN into Google will get you one of the 'parts' websites that give a cross-reference to the manufacturer and their product code. (I did this with my MA-675 9 metre mast to get most of the parts list). Once you've got that much information you can expand the search a bit. The canvas case points to it being Larkspur, and stayplate with an extra hole for a halyard points to HF, so the SR A14 (aka BCC 30) is a very likely candidate. A look in the user handbook should confirm that. Chris. Better get your Gnomes hat on Chris! Quote Link to comment Share on other sites More sharing options...
jarrett Posted September 28, 2016 Share Posted September 28, 2016 Here you are with nsn's Quote Link to comment Share on other sites More sharing options...
armouredfarmer Posted September 28, 2016 Author Share Posted September 28, 2016 Yep that's it, where did you find that? and could you get me a copy of the erection instructions please? Quote Link to comment Share on other sites More sharing options...
jarrett Posted September 28, 2016 Share Posted September 28, 2016 Thats from the a14 user handbook dtd1966 and i will scan the relevant page and post later although probably the same as the small Clansman masts. Quote Link to comment Share on other sites More sharing options...
Chris Suslowicz Posted September 28, 2016 Share Posted September 28, 2016 Yep that's it, where did you find that? and could you get me a copy of the erection instructions please? Interesting that it has asymmetric stays! Working out the erection instructions should be fairly easy, you just need to find the peg spacing by trial and error. (Guessing at about 12 feet for the 'inward facing' stays and 18 feet for the two ends as a first cut.) 1) pin the bases to the ground to suit your long-wire aerial (length of aerial + a few feet apart). 1a) measure around 12 feet at 60 degrees from the base either side of the aerial direction and drive a peg in 2) lay the poles out facing inwards, sockets downwards (towards base plate) 3) place halyard cleat over end of first pole, add two (or three) poles, then one stayplate. 4) clip the two short stays (24-ft) to the outer pair of the "group of three" holes in the stayplate. 5) run the stays out at 60 degrees to the line of the aerial and attach to pegs (leave slack!). 6) clip the shorter of the single stay to the single hole in the stayplate. 7) run that stay out towards the base of the mast (and beyond). 8) add the remaining poles to the mast and the stayplate to the top. 9) connect the two longer stays to the outer pair of the "group of three" holes in the stayplate and to the two pegs. 10) connect the halyard pulley block to the third hole. 11) attach the remaining (50-ft?) stay to the single hole in the stayplate and extend it past the base of the mast. Now the fun part, the first go at erecting it (for which you need 4 or 5 people). One person holds the long stays at the rear of the mast, a second person holds the top of the mast, two more hold the short stays (one at each peg), and the last one keeps the base of the mast in position while it is being raised. 12) lift the top of the mast and slowly "walk it up". tension should be applied to the back stays to assist the lift, and the two front stay people should keep it centred. (Do this carefully - it may be worth starting with "half a mast" to get the peg spacing sorted. 13) once vertical (-ish), decide on the rear peg position, drive that in, and attach the two long stays to that. 14) Adjust stays all-round to get the mast vertical, do not over-tighten the stays. 15) Repeat for second mast (but you now know the peg spacings required). 16) attach wire aerial to halyards and hoist. 17) Sorted! (I hope.) (It may be that only one mast was intended to be used, with a sloping wire, but this will do you for a dipole.) Good luck, Chris. Quote Link to comment Share on other sites More sharing options...
jarrett Posted September 28, 2016 Share Posted September 28, 2016 (edited) Here you go,although be carefull when walking it to vertical,do not let it whip as it will break(not from experience) Edited September 28, 2016 by jarrett Quote Link to comment Share on other sites More sharing options...
Chris Suslowicz Posted September 28, 2016 Share Posted September 28, 2016 Here you go,although be carefull when walking it to vertical,do not let it whip as it will break(not from experience) You need the page with Fig 27 on it, because that's the critical bit that shows the ground plan and where to position the stay pickets. Can you scan that one, please? Quote Link to comment Share on other sites More sharing options...
armouredfarmer Posted September 29, 2016 Author Share Posted September 29, 2016 That's great thank you all very much. Quote Link to comment Share on other sites More sharing options...
jarrett Posted September 29, 2016 Share Posted September 29, 2016 ...And finally Quote Link to comment Share on other sites More sharing options...
Chris Suslowicz Posted September 29, 2016 Share Posted September 29, 2016 ...And finally Hmmm... all the images seem to have vanished without trace. :??? (Not that I have one of these masts, I was just interested (but not enough to ferret through the archives).) Chris. Quote Link to comment Share on other sites More sharing options...
jarrett Posted September 30, 2016 Share Posted September 30, 2016 Right here is the guy line setup and to be honest i cant be arssed scanning again as everything is packed away,i know what happened i saw the pictures in the folder and thought i will clear that lot out not knowing it deletes them from the thread. Quote Link to comment Share on other sites More sharing options...
Chris Suslowicz Posted September 30, 2016 Share Posted September 30, 2016 Right here is the guy line setup and to be honest i cant be arssed scanning again as everything is packed away,i know what happened i saw the pictures in the folder and thought i will clear that lot out not knowing it deletes them from the thread. Thanks. That is a weird arrangement and must have been difficult to set up in a hurry with two pickets at 14 feet from the base and the third at 32 feet! So much easier with the modern "piece of string" to set the picket spacing.:-D (Mind you, I'm going to have fun trying out my SP48 masts in due course. I may have to make up a "cats cradle" of string with all the relevant peg positions and alignments marked for when setting it out - it doesn't help that the mast is erected at 45 degrees to the intended line of the antenna either.) Chris. Quote Link to comment Share on other sites More sharing options...
jarrett Posted September 30, 2016 Share Posted September 30, 2016 The guys do have colour coded tags on them to denote length but still an embuggerance,for a dipole i would use the mast but for the end fed as well?only reason behind it i can see is that the fibreglass does flex a bit and with a dipole the steeper angle will help to restrain it but i have had mine up a few times and never managed to get it vertical yet. Quote Link to comment Share on other sites More sharing options...
armouredfarmer Posted October 1, 2016 Author Share Posted October 1, 2016 Thanks again Jarret, might have a go at putting one up this weekend, I'll report back on the fun and games :laugh: Quote Link to comment Share on other sites More sharing options...
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