sunray

I installed some dimmers in a nightclub and we promptly got blamed for significant flickering problems on the LED pars, the original DMX installation was 13x13 PAR's, the 'main' DMX line ran along one side with choc bloc joins to provide the feed to the first PAR in every line. It worked perfectly until we added the new dimmers and incandescent fittings which were not even a part of the DMX set-up. What he didn't know is I had already used some DMX cables elsewhere... He is part of the shows crew and one of the scenery guys had already tipped me off that this guy removes the cables very quickly after the final show and will/does remove everything, especially cables that do not belong to him. No I don't try to offer advice to people like him, I learnt that one a long time ago. That's a difficult one when every single fitting in the system has 3pin connectors. I have always been concerned about this but in practice I've only found it to be a problem if something is not right, such as no terminator or some audio running unbalanced.

Indeed Agreed, but Beldon 9500 style cable should be 110Ω which is what the DMX spec was written around and is used for most installed tielines.

I've seen and heard all sorts of arguments about using the right cables for DMX but today I stumbled into the opposite while setting up for a show. The official tech guy has insisted that only his cables are used, for 2 reasons: 1) There will be no issues identifying his and others at de-rig, 2) They are 'good quality' cables. So I picked up a couple of cables with blue marking rings on the XLR's (DMX) to use for the intercom and was told they would not work for audio and in no uncertain terms how stupid I am for trying to use DMX cable incorrectly, I asked what the problem is and a long lecture followed about how DMX runs pin 3 hot vs pin 2 for audio, even to the point where plugs were opened to show where the red wire is. It didn't help matters when I saw the poor workmanship and asked if the plugs were terminated by a monkey, another lecture about how he has been making cables for 10 years, my 50 years worth was oh so irrelevant... Good god I didn't have to edit the CR's back in...

I have found I need to adjust the sidetone pots almost everytime I use the bluecom sets and had assumed it's due to the number of units in use, until today while setting up for a show next week I set up the same 4 beltpacks as last time. The difference is the PSU used, last time I used my homemade unit and today the 721. I substituted the homemade and they returned to 'tuned' state. I adjusted them for the 721 as I wanted the aux in facility, out of curiosity I then tried te other channel of the 721 and again out of balance. Has anyone else noticed this?

I had all of my Trantec S4 beltpacks (4xCH70, 4XCH38) out on hire a little while back, customer wanted these to match up with other kit, and checked them over on return. I needed 2 during the week and randomly took 4 with me (3xCH70, 1xCH38) I found the range of the CH70 sets struggled to cover the 20m indoors. I had the RX's on top of a L/S at 7ft (very normal for me) and the speakers were standing with packs in breast pockets facing L/S. CH38 body pack and CH70&38 HH's showed rock solid signals of 3 or 4 blobs and occasional aerial change. CH70 body packs kept dropping out, I tried all 4 frequencies and all 3 packs. After the event I tested outdoors and found some similar results reaching 40-50m max, I know I've done better than this in the past but CH38 went to the end of the field. The strange question, all 8 aerials are the same length and a niggle in my head says they were different. Could anyone measure theirs for me please, I'm currently working on the thought the hirer did a bit of swappage and I now have all CH38 aerials.

I'd completely forgotten about this thread from nearly a year ago. Bearing in mind I'm nearly retired and my invoice count has plummeted to an all time low, of my 47 invoices since 5th April, 29 of them mention True 1 connectors.

<br /><br />No they are M3<br />Ah I thought m4 seemed to big but it's rare I take one off.

Are they 4mm threads?

Dam, I'll not be able to make that one ...

I absolutely love this thread, sensible request for help and appreciated sensible replies. Long live BR

Of course, what else is it used for? :)

I have been thinking along the same lines but wanted to test it before posting. I fully expect a Dect phone to require the DC element across the line for internal signalling. I was planning to try with a transformer 477 and use the BlueCom 24V power with some current limiting to energise the phone line. My big concern: some (possibly cheap) Dect phones have a tendency to feed the I/C audio back out at a low level with a small delay which may be too noticeable on headphones. Personally I'd look at using full duplex radios, it's well proven and non digital so less prone to falling over.

Already in there (I think 1A) and 1.5 ohm resistor which sit between the original 2200uF and the 100uH. There's also a combined mains IEC/fuse/switch/filter and a LED/10K across the 24V o/p. Did the show tonight and it was picking up very low level DMX, the bunch of cables running length of hall must have been dressed differently but otherwise perfect. Next item to develop: remotely controlled switch to add comms into show relay. Should be easy, balanced I/p, simple mixer, balanced o/p and modified board letting the call function operate trigger a device like the mic switch does. Edit: In fact now that lay in bed thinking about it, belt pack board has everything in place - Alter mic preamp to balanced line level I/p, let call cct trigger J175, remove cap between mic buffer and bus and move hybrid pot from I/p of mic buffer to o/p. h/p amp provides balanced o/p. The only question I can't answer from bed is 'will another XLR fit in place of the dip switch on the back panel'?

Wow, all the effort has culminated in 6 belt packs and tonight we used 3 for dress rehearsal, and they worked perfectly. We decided the original mic switch was not an ideal design being so close to the volume control and the complication of getting a gloved finger in the limited space to use the (1) position. As we ran out of time I mounted one of the original switches upside down on copper wire (strands from 4mm conduit cable. So its 1-0-(1) instead of (1)-0-1. I will need to revisit this as they're currently only held in place by the 3 bits of wire and the hole in the front panel and will fail. 5 of the 6 worked instantly at switch-on, the 6th believe it or not was R27 being very high resistance in the order of several mega ohms. So far we have only one power supply which is a 60VA 18-0-18 torroid, bridge rectifier and a pair of 2200uF caps built into a diecast box. Origin unknown, I added a pair of XLR 3F's and the R-C network, oh and one of the 100uH inductors and 4 off 4700uF's. All a bit of overkill but totally free from the junk box. Massive thanks to Brian and boatman for all of your R&D effort, board designs and help. Plus the several other people I've been chatting to. I've purchased 3 of these: <a href='https://www.ebay.co.uk/itm/Headphones-with-Mic-for-PS4-Sony-Play-Station-4-PC-Stereo-Wired-Gaming-Headsets/123064152765?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649' class='bbc_url' title='External link' rel='nofollow external'>https://www.ebay.co....872.m2749.l2649</a> which seem to work well but one does have to alter wiring within the cable mounted vol control/mic switch. Again thankyou and very well done.

I have 6 of the originals Alps 10x5mm buttons available for sale, they have cost me £1.52p each from Mouser.

As above, it is too big for the led I haven't done it, but I eyed it up and thought it will fit. Having said that I have not used the LED mounting block [cpc no longer stock that item] so it takes up less space. My intention has been to apply a blob of hot melt glue but we don't think it is essential as the LED leads are quite short.

I looked at these, actually have 2 'in stock' but they are 12x7mm, the current hole will need the hole filing out as it is designed for a 10x5mm. If we begged Boatman hard enough perhaps we may persuade him to do another version of the panels to accommodate the larger button or perhaps the round version.

I got my boards from Elecrow and found them to be very good, I struggled with the order and ended up with 2 lots of circuit boards during the kerfuffle of the selection of emails that it took to sort out, but read their ordering information correctly [like I didn't] and it should be pain free.As such I have ended up with more than 10 spare circuit boards.The way the standard boards work is for the front panel to stay on the enclosure and removing the 4 screws of the back panel the whole assembly slides out. So it wold be better if the LED bezel could be modified.

Yep that's it, I offered ideas which will need completing to make the appropriate system for the user. Most of the kit for satellite [or pro TV] work is usually F type unfortunately but I have in the past used belling lee type patch leads that are actually a coax with push fit F types and adapters, I have cut the cables in half to make 2 BNC's or TNC's to F cables.

Looking good.In the 'standard' design they use a plastic block to mount the LED for it to poke through the front panel, CPC have discontinued the original so we have just bent the legs and soldered at the right height the plan was to encase in hot melt but we seem to have forgotten. I like the bezel, does the LED just slide in from the rear? Similar things I've seen don't.

plugged into one of these http://cpc.farnell.com/sac/ae9701/in-line-sat-amplifier/dp/AP02364?st=satelite amplifier then something like this http://cpc.farnell.com/vision/111730/splitter-2-way-5-2300mhz/dp/AP02599?st=satelite amplifier

Ah, OK. All understood. I was a little concerned about the dip switch but once fitted it seems OK, we considered gluing it to the board but after assembling the first decided to leave as is and maybe address it later if necessary.For a moment I was getting excited about the square button... We are doing the 6 with the correct size button but any more we will file the hole to take a 10mm round button as we have a few in stock, it won't be perfect but at only a 1mm error hopefully it will not be too bad.I intend building a radio interface module, basically a modified beltpack board with a PSU, also suitable to run the radio's.

OOOO that's interesting, it may cause a few problems in the industry.

Interesting, the guys spent a lot od R&D time on this and I spent a lot of time looking at project before investing. In my case there are 3 of us who regularly work together and planned to make 2 beltpacks and a psu each. We have made 6 boards up and 5 worked instantly, the sixth is distorted and over loud, I assume that a wrong resistor has been used in a feedback circuit but it has not been faulted yet.I have been very impressed with the whole project so far, the only thing we have not followed is the mic switch as the 'follow spot' guy predicted it will be too fiddly while wearing gloves. I wonder what alterations you are intending?

I guess they are supposed to complement the S4.4 series etc and they are not line level output. Loud mic level yes but not line level.