Keith_

again, congratulations Ynot. Interesting to note how many BT (GPO) engineers have contributed to the entertainments business, especially Am Drams over the past decades. I work for a university as an academic - a properly busy high pressure job, contrary to popular opinion. I'm about to put down my proverbial chalk (we stopped using that 20 years ago) next year and will certainly be glad of it. Long before I got into that profession, as a youth, I had a small business doing PA systems and recordings, so a few years ago, having retrieved some very old kit, I decided to get back into that and now have enough to put on a decent show or two (including digital, that I had to learn from scratch). Aiming to make it a proper business, but just doing a few gigs at present (income declared on the TR!). Thing is, like other over 60s here, the challenge is that is it just knackering lugging heavy boxes around and all that, staying until long past normal bed time to wrap up and being presented with incompatible sources at 30 seconds notice " my dance music is on this, can you plug it in?". On the other hand, when a client stands back and says "Wow!" in admiration, yes, it is worth it.

Happy ending: New iron kit arrived today. Tried it on 300C - not enough - went up to 380C (I think 400 is max) and suddenly the job was as easy as soldering an XLR. The Atten ST-80 seems pretty competent (though I've only used it for about 20 mins so far). Of the several tips I bought, T900-3C seemed to be the best for this job. So I will be using the Atten on my bench from now on and the Iroda pro 120 can do what it is best at - soldering in the field, up a ladder, on a gantry, in an underfloor crawl space and round the back of the big tent.

Thanks folks, this is excellent advice. Sunray's technique is exactly what I was trying to do (as he said: scaled up version of XLR), but I guess my iron just doesn't have the welly for it. I realise my use of the Iroda gas iron is just a habit built up from field work (old familiar tools etc.) and I need a well controlled electric for the bench. I would love a JBC station (Indyld), but it is well beyond my means. The review of irons was really useful, Sunray, not so much for the specific models as for explaining the factors determining real world performance. I think the problem with the Iroda is that the tips are quite lightweight and of course there only the crudest of controls (though it is actually rather nice to use: very responsive, like the gas hob in the kitchen). After a bit of hunting around, I have bought an ATEN ST-80 kit with an assortment of bits. I expect that will get it sorted and will be a good investment (I got from Telonic Instruments - same as Rigol- who offer a better price than CPC).

I agree with both of you and have some other tips on order and will use added flux. I think the iron is powerful enough (allegedly 125W), but probably the 3mm tip has insufficient heat capacity. Of course I have larger tips now, but they don't fit into the work without touching things that ought not to get hot. I saw some potentially useful bent tips that might help, but designed for another (very expensive) make of iron. I am particularly keen to hear from someone who has specific experience of tacking these Speakons with 4mm wire (otherwise maybe I should ask a brain surgeon to have a go).

If you are after something lighter and cheaper, I think SoundGear Orbit 4 is worth a look for mid tops (definately the 'upgraded' version). You get a lot of SPL for the weight and they are quite well controlled in dispersion (being horn based), yet still reasonably smooth. James makes them to order, so not good if you are in a hurry for them. He also does a compatible bass scoop.

Hi Folks, I thought I would tag onto this old thread, rather than starting a new one. I face making up 12 4mm^2 speaker cables with NTL4FXX solder connectors (IP65 rated) and the few I did in the past were total pigs to get right. Looking for tips if you have any (no pun intended, though recommendations of iron tips will be good). The problem I find is that there is very little space to get the iron in there with a fat wire in the solder cup and I can get either the cup hot enough, or the wire end, but not both, without also melting the plastic bits. I wish Neutric did these with screw terminals like their ordinary speakons, but I need these STX type for what I am doing. Any suggestions? I normally like to use an Iroda pro 120, but maybe it is not the best for this job. Thanks.

Yes, I am sorry, I made a not very good mental note last time I saw them. CPC seem only to do the StageLine children's size and it terminates in a mini XLR, unfortunately. I could not find a mini TRS in that size (and StageLine website is very unhelpful). I have in the past had Micronic (https://micronic.co.uk/collections/ear-hook-microphone/products/ear-hook-headset-microphone-for-sennheiser-3-5mm-locking-jack-transmitters) on youths (the adjustment of the boom helps), but not properly tiny people. I'm sure I have seen small ones elsewhere, but racking my brains, I still cannot remember, sorry.

I agree - they stay on, but are not very comfortable. The sound quality and level varies quite a lot depending on how the mini gooseneck is positioned but you get what you pay for. If you want something better, that will last, Senn ME3 is the one I recommend, > £60 new, but s/h often on ebay. Having said that those wee wire things are less obtrusive, which is obviously important for am. dram and musicals. I believe you can get them in child size too.

I'll check it out, Gary, thanks. In my applications, things have to be able to take some rough handling and be fine outdoors. I put Gutmann 'dead cats' on all my mics (outdoors), for example, so would expect to use one on the wee headset mic. I particularly like the juxtaposition in the attached photo (if you see what I mean). (Sennheiser MD46 with Gutmann screen on PA duty at a rally).

I see. The consensus is around what I was thinking of doing, but I am surprised there is nothing simpler. The point you all made about putting extra information on the IEM is a very good one and I will be doing that now I know a separate IEM channel is the way to go. I will put a feed from the walkie talkie link between start and finish onto the desk, sent out on a monitor just for the announcer - then he will know what is going on at both ends (but we will have to make sure he doesn't try to answer those on the other end with his PA mic live). Previously the announcer has had a walkie talkie in his pocket (these are Kenwood TK3501s). More than about 35 years ago I offered one of those Coles lip mics, but these days I haven't enough requirement for that (at the cost of them), but I think I might get a Senn HMD 300 set to upgrade. Thanks for advice from the usual gang.

Hi folks, For a while I have been looking for a cost effective solution for a customer who gives commentries at very noisy motorsports events etc. I have given them a Tecpro headset in the past, but it is wired and I really want to give them the freedom of movement from wireless. The user needs only to hear themself in the phones. Of course I could have separate RM and IEM, but that seems a waste. The intercom sets available all seem to be wired (or seriously expensive digital wireless) and ott. for this. In fact I expected to find an RM transmitter beltpack with an AF output for 'local' phones monitor: that would be ideal. Am I missing something here? Thanks.

Good point, DrV. Electrolytics recently featured in the Sound Forum - zero ohm - and could indeed be an issue. Though in this case I doubt that explains the same rate of decline in all the lamps at once, I will open them up and have a look. The PSUs may be at fault because I notice the lamps do not draw their rated power (not even close). They are from a very good manufacturer, though.

Thanks chaps. Mushi roughly corroborated what the technical document I linked to was saying, though perhaps older technology would have deteriorated faster. 50k hours is roughly on all night every night for a bit over 11 years, which would tally with outdoor lights that might have started service, e.g. illuminating a building, in 2011. Judging by the (high quality, but old) units I bought, that is not impossible. I take it, though, that modern LEDs from a reputable manufacturer should be fine for many years of service (as long as they don't get battered about). Don makes a point also corroborating the document - overheating reduces lifespan and unfortunately the mode of slow degeneration tends to increase heat in the diode leading to a viscious circle. I agree with Timesabres point about good quality and spare parts - it's one of the reasons I prefer good s/h over cheep new. Any more comments?

Hi Folks, I am new to lighting (came from sound), but occasionally I am asked for lights too (outdoor shows*), so I thought I would start getting a basic outdoor light set together. On a small budget, I have always preferred quality s/h over cheep new. Recent exerience teaches me this does not apply well to LED lights. After some disappointment, I have been reading: https://www.digikey.com/en/articles/understanding-the-cause-of-fading-in-high-brightness-leds and linked pages. I am here to get the opinion of lighting experts regarding aging and used equipment in this area. Many thanks. * E.g. I did sound for a set of local choirs in a town square on a winter evening and there was no lighting, so they were not best presented.

Just copied from Canford website: The frequency range 470 – 790 MHz is used for UK television broadcasting - but can also be assigned for radio microphones where they do not cause interference to television reception or are liable to suffer interference from television transmissions. The pattern of television coverage however is complex and constantly changing so contact Arqiva PMSE to determine whether given frequencies are available to be licensed at a particular location. Licence fees for co-ordinated frequencies £8.50 per frequency per 48 hour period – using the PMSE Licensing on-line application facility. (Or book direct with PMSE Licensing in writing – N.B. Then a minimum charge of £28 applies). Long term (up to 1 year) annual charge available for indoor fixed sites only: £28 per frequency or £168 per UHF channel block. Contact details PMSE Licensing 2nd Floor Riverside House 2a Southwark Bridge Road London SE1 9HA Tel: 020 7981 3803 Email: pmse@ofcom.org.uk Web: Ofcom - PMSE Licensing Obviously a good idea to check with PMSE to confirm. All the best...

Thanks mnorwood. So it's just a giant capacitor acting as a sort of flywheel or ballast, with a very basic high-pass filter to compensate. Sheesh! One of these for an experiment? https://uk.farnell.com/kemet/als70a203kf100/cap-20000-f-100v-alu-elec-screw/dp/2729166?st=20000 mf capacitor (legal issues asside, I won't be trying it on any expensive kit)

Great suggestion, Richard. I had wondered about taking power from the incoming audio (kind of cheating). You point about cable loss seems reasonable: I thought that was the basic reason for 100V line. If for simplicity we just consider resistive loads, then the current, at least for the first few speakers on the line would be enormous and require exceedingly fat cables (https://www.grc.nasa.gov/WWW/k-12/airplane/ohmrpar.html). It seems using that zero ohm thing would have most of the energy going into resistive, rather than inductive load (a very expensive heater). The low duty cycle PWM sounds analogous to a class D amp. Is the theory that current is effectively proportional to pulse width? I don't think I understand it yet, do you mind explaining or pointing me to the theory? One day I will learn how to read patents!

Well, that is interesting. They explicitly say there is no transformer and the thing handles 4kW, so I think there is not room in their short 2U box for any big power handling passive components. I had a quick look for relevant patents and found this: US20170070195A1. Is that relevant? If this thing works and is not too pricey, I would be up for using it. UK distributor: https://www.dizzyfish.net/

Finally got round to real-life testing antennas (I have been off with a total rupture of the quadriceps tendon, which put me in hospital for a week, now on crutches). What I found was that for Ch70 this thing works splendidly: https://www.rfsolutions.co.uk/antennas-c8/wall-mounting-gain-antenna-for-gsm-3g-and-wifi-p161 It only costs £37. Unfortunately, with my injury, a lot of work I had in the diary is up the spout - you never know what will happen next.

I just tried one of these https://www.farnell.com/datasheets/1641049.pdf and got 30 on the signal meter of my Senn G2 receiver with an skp100 placed 80m down the road, on the ground with parked cars in the way. I paid £50 +VAT for it about two years ago, they are £93 on CPC now. I bought it for communicating between speaker towers (for RX end only of course) - line of sight it is brilliant, but its beamwidth is too narrow for radio mic work. The smaller ones, I found not that great, so will continue experimenting. I have not made a cone antenna yet - will keep you posted.

Oh yes, Sunray, I remember we discussed them before. Good for Ch38, but their rejection at 862MHz to stop mobile phone intereference would probably put the damper on Ch70. I might have a play with some bits and pieces this weekend if it is not raining. Thanks.

That's very good, David. I thought the graph I was looking at fell off a bit hard. RCF are underselling themselves in their advertising lit. By the way, I recently started lusting after some Funktion one horns ... that is until I saw the price of them. Fabulous kit, but you could buy a yacht for that kind of money.

I've been thinking about this. To achieve the rather broad bandwidth, it is likely to be something very like a bow-tie antenna inside ( https://antenna-theory.com/antennas/wideband/bowtie.php ). The plastic lolipop shape is a weak clue. It is passve and the only thing I can think of is that the solder connection between its feed and the foil has failed, which I suppose might happen with a heavy knock or bend (e.g. if someone actually used it as a table tennis bat). As with all these sort of things, there is a small, highly specialised, enthusiast circle devoted to home brew antennas (URL above is an example). I expect the £120 is for developing the exact shape and use of well manufactured parts, but really it is stretching willingness to pay to the absolute limit (the thing itself probably costs less than a fiver to make). I am going to muck about with some copper foil and see if I can get anything resembling decent performance (just out of interest). By the way I see broad band mobile phone paddle antennas for about 1/10 the price, but unfortunately now 1 and 2G are gone, they start above 700MHz. I guess Sennheiser correctly believe if you want Sennheiser, you have to pay Sennheiser prices (or substite your preferred RM kit maker).

Have a look (if you did not already) at the freq response published by RCF https://www.rcf.it/en/products/product-detail/sub-8003-as-ii?p_p_id=it_dvel_rcf_products_frontend_web_portlet_ProductDownloadsPortlet&p_p_lifecycle=2&p_p_state=normal&p_p_mode=view&p_p_resource_id=downloadProductFileEntry&p_p_cacheability=cacheLevelPage&_it_dvel_rcf_products_frontend_web_portlet_ProductDownloadsPortlet_productCode=STP0145&_it_dvel_rcf_products_frontend_web_portlet_ProductDownloadsPortlet_profileId=239890 You will see it drops about 10dB from 50 to 80Hz and keeps going down at that rate as f increases. Your 932s are good down to 70 or 80Hz, so I expect L2 or L3 would be best, but agree with David from the Granite City above about experimenting. Also to note (if you want) the 932s are roughly cardioid polar pattern (horizontal) above around 1kHz, so 40 degrees or so off axis (of either of them) will be a bit wooly (especially with audience absorption) - beam width quoted as 90 degrees at 1k. As a rule that is not a big issue in small venues; it may be best to point them slightly inwards, not parralel (depends on where the walls are). I imagine you are putting the bass box in the middle FOH. The 932s are a bit less dB, so I don't expect them to be out of balance with the bass. You can use some pan to help avoid standing waves and feedback from the tops (it might make a bit of difference in some tricky, cramped situations). Returning to David's advice, I would play some familiar music through the system and walk around to see how it sounds in different parts of the venue, tweeking to taste. The speakers should serve you very well.

Thanks very much, Tom. I will give the bunch in Ireland a call (I can take it to them in the car without too much difficulty). I notice they also sell some components, which could be handy. As for the firewire, yes, very fragile it is, but has been treated like a live bomb-fuse from the beginning and still works. It is plugged into a dedicated Mac on OS10.6 (!!). On another recent thread, someone was saying they ran one in a school (I would not expect that to work for too long, but apparently it did). Personally I have an affinity for the old stuff (and a small budget).