timtheenchanteruk Posted October 11, 2012 Share Posted October 11, 2012 Got a rack of trantec S4.4s, tuesday developed a fault on one receiver. It sounds like the receiver is slightly off channel, is some rf noise coming through with audio, but not constantly, the same artefacts you get on a fully tunable system if the frequency is off by a couple of points of Mhz. I have narrowed it down to the receiver, as the belt pack is fine on another receiver, but other beltpacks develop the same noise with the faulty receiver.I have also had it disconnected from the ADU on just a pair of antenna (to see if it was an ADU issue) any idea, or know how to tweak it back? guessing id need some kit I dont have, like a signal generator, oscillascope (cedd, you got one??)The system is just over 22 years old, probably only done 12 shows, all been rigged/run by me, a beltpack failing I could understand the receiver though... They are stored in a house as well, so its not temp/damp issues. Forgot to say, have emailed Trantec to see if they can help Link to comment Share on other sites More sharing options...
Simon Lewis Posted October 11, 2012 Share Posted October 11, 2012 Have you tried adjusting the receiver's squelch control? Link to comment Share on other sites More sharing options...
IRW Posted October 11, 2012 Share Posted October 11, 2012 snip... The system is just over 22 years old Maybe it's time to replace :P Link to comment Share on other sites More sharing options...
timtheenchanteruk Posted October 11, 2012 Author Share Posted October 11, 2012 typo :blink: 2y/o... I do have some 20 y/o sennys & trantec vhfs!! Link to comment Share on other sites More sharing options...
Jon Wiles Posted October 11, 2012 Share Posted October 11, 2012 Speak to Mike at MLEC http://www.mlec.co.uk He's very good and will re tune/service for you Jon Link to comment Share on other sites More sharing options...
cedd Posted October 11, 2012 Share Posted October 11, 2012 Yeah I'd really suggest getting it looked at properly. I suspect it'll be PLL so very little to adjust internally - at least with any ease! I do indeed have a scope and also a spectrum analyser (that drifts like mad and weighs about the same as a small bungalow!) but I don't think either would be of use to you unless you were very brave and had a service manual! Have you tried different receivers on the same channel to check it's not an interference issue? Might be the case. It can be anything from a faulty emergency light to the pub down the road! The only other person I know locally using channel 38 is me, and mine are switched off, honest! Link to comment Share on other sites More sharing options...
timtheenchanteruk Posted October 11, 2012 Author Share Posted October 11, 2012 Have you tried different receivers on the same channel to check it's not an interference issue? Might be the case. It can be anything from a faulty emergency light to the pub down the road! The only other person I know locally using channel 38 is me, and mine are switched off, honest! Not tried that yet, will do when I get to the town hall this eve.there's no RF when the transmitter is off, ill try turning the squelch down see if something breaks through. Oh, and I lied, its a 4.16 system, not the 4.4 going to have to dig the manual out, cant find one online for the Ch38 4.16, want to look up what frequency "channel 2" is Link to comment Share on other sites More sharing options...
Jon Wiles Posted October 11, 2012 Share Posted October 11, 2012 According to the manual ch 2 should be 607.500 if ch 38 and probably 863.725 which makes that Ch70 http://www.trantec.co.uk/documentation/s416rxe-aw_sa1e.pdf Dont forget that after Jan 01 2013, you won't be able to use anything after ch 4 (if it is a ch 69/70 receiver) only Ch38 Jon Link to comment Share on other sites More sharing options...
timtheenchanteruk Posted October 11, 2012 Author Share Posted October 11, 2012 thankyou. 607.500 it will be then. nope bought mine for Ch38, I'd been nursing my old kit through till I could get 38's Link to comment Share on other sites More sharing options...
timtheenchanteruk Posted October 13, 2012 Author Share Posted October 13, 2012 OK, feel an Eejit now (thats what long working hours does, numbs your problem finding brain) tried another receiver on Ch2 (607.500) the problem moves around, so, it not a receiver fault at all, but an RF one, not had time to take another brand/model it to see if it affects that as well. Link to comment Share on other sites More sharing options...
cedd Posted October 14, 2012 Share Posted October 14, 2012 Interesting.... sorry I've not replied sooner Tim, I've been away. Could have brought one of my receivers up to check on that as well. Mine have RF level displays on them so we stand a chance of direction finding the source. I'll have a look before we're in there next and see what I can find. Worth powering up your receiver rack when you get it away from the venue and see if it's still an issue. It's not unknown for receivers to re-radiate, particularly their IF when their front end filtering breaks down. Doubt it'll be the case with your newer PLL receivers though, but I've seen it before on older stuff. Link to comment Share on other sites More sharing options...
timtheenchanteruk Posted October 16, 2012 Author Share Posted October 16, 2012 checked receivers on sunday (just to double check) and they were fine. no RF breakthrough when the bodypack off, even with my squelch right down, like I said in the op, it was an acompanying rf noise when audio came though (although it was pretty noisy if you turned the pfl up in the headphones, more noticable with audio coming through) Its exactly the same this as if you were using a fully tunable system, like a senn with the rf off by a few points. just to add, sunday, at home... I don;t have ollys number, but if you could let him know, might save him a problem he's in next for fiddler. Link to comment Share on other sites More sharing options...
cedd Posted October 16, 2012 Share Posted October 16, 2012 I nipped in to the venue today (actually to drop off a subwoofer that I've just repaired) and took a receiver with me. As you say, nothing visible on the RF display. Sadly as I didn't read your first post properly, I didn't take a transmitter with me so it's not been particularly conclusive! I'll be working with Oli on Fiddler so will put him in the picture. Hopefully between then and now I'll get in to the place with a decent spectrum analyser (perk of the day job!) and see just what's bouncing around. It'd be interesting to know if you saw the problem when the rest of the tech supplies were powered up, or if you were still seeing it with lighting, amps and the video system switched off? Might just help narrow down the source. It'll be something really simple! I had an almost identical problem at work and it was a flourescent tube in an office emergency light that had died. That said, it sounds like it's been quite isolated to one frequency. RF noise from an arc tends to be reasonably wide band. I guess only time will tell. Not done any direction finding in a while so this could be fun! Were your receivers at front of house or at the stage? The bar's just been refitted and I wonder if it could be related? It's very close to front of house. I'll report back! I'd considered moving this conversation to private messages, but as a few other people have chipped in and as it might be useful to someone else in the future in a different venue, I've kept it public.Hope people are happy with that. Link to comment Share on other sites More sharing options...
timtheenchanteruk Posted October 16, 2012 Author Share Posted October 16, 2012 fine by me.actually, bar may be worth a look. Nothing on the Tech (sunday) Tuesday (dress) was when it started, they were setting the bar up at the same time, bar stuff also going on when testing (no finger pointing, just the full picture)Testing done with and without lighting, and my kit powered up (turned stuff off/unplugged one by one to see if it was something of mine causing issues, PCs being a known culprit in the past) Receivers FOH, with omni antenna on front of balcony, although proximity to the antenna didn't seem to improve/change anything, same results stood under the antenna, as on the stage, and like I said tried it directly onto a pair of receiver mounted antenna to see if I had a dodgy splitter issue Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.