Line 6 Digital Wireless Systems

[ramdram]

Battery life indicator, I don't suppose it can be an exact science if the ambient temperature is up and down.

 

I gather the battery chemistry is "endothermic" in that the reaction is affected by hot or cold. Some of us may recall the early NiCad batteries on camcorders, when a top tip was to keep the spare batteries warm (under your coat, say) when filming in the winter. Or how lead acid car batteries seem unhappy when the temperature is below freezing.

 

Ref the ISM band, I would be a tad unhappy if some medical kit WAS affected by rf interference. And, if you read the blurb on these devices (Part 15 of the FCC rules, sections 1 and 2) there is something to the effect that said devices are not to cause rf interference and, at the same time, are supposed to be able to cope with rf interference.

 

Perhaps a bit of work in that department is needed?

[paulears]

For info, the wall warts from Thomann are two pin varieties, which I rather expected from them.

[boswell]

Now that at least Paul & I have 4 or more of these systems, anyone know of a 9vdc 2A linear power supply that we can use to power them?

9V supplies seem to be getting rare and they are mostly switched mode.

[ramdram]

Of interest?

link 1

 

link 2

 

Moderation: quotes fixed

[cedd]

Are you looking for linear purely for noise issues? I'm just starting to plan my 2 x channel 38 racks of 6 receivers and was hoping to do a psu (12v) for each rack, but with a link cable between the 2 and diode combiners such that if a power supply in one rack failed, the other could run all 12 systems. I was looking at SMPSU's though. Getting a linear for that current could be a fair bit more expensive!

[boswell]

Hi Cedd/Ramdram,

Yep, it's the possible noise from switchmode and also any earthloop hum problems. I like the concept of a 100% transformer isolation.

I'm just wary that I introduce the same problems as Dell laptop power supplies

The Roland power supply RamDram links to is double insulated and has no mains earth but I think it is switchmode, not sure yet

It's a good find nevertheless.

 

One point to consider on earth loops, the -ve of the RX DC power, the aerial screen, the RX chassis and the RX audio output ground are all common.

So Racking them up will common them all to the rack. Then if you have the rack earthed, you have introduced a possible earth loop

 

I'm just starting to plan my 2 x channel 38 racks of 6 receivers and was hoping to do a psu (12v) for each rack,

What do your Ch38 RX take?, 400ma each max at a guess, so a 12V 5a will power the lot, plenty of 13.8V linear ham radio powerpacks around that will do that sort of load (I think I've got 2 in my shack, Pye & Motorola) and the regulators can be turned down a notch (or use 3 series diodes).

[Lamplighter]

I've built quite a few receiver racks over the years using switched mode supplies. I have never experienced earth loop problems using the XLR outputs or any RF noise problems. I have also used large numbers (hundreds) of switched mode supplies for commercial radio systems without either of these problems. Trantec, for instance, supply their racks fitted with switched mode supplies with 3 pin IEC inputs. I don't believe it's likely to be a problem if you use supplies from a reputable source.

Brian

[Rob_Beech]

I notice the G3 PSU's for the Ch38 are switch mode. But the Ch69 ones aren't. A colleague pointed this out to me the other day. I have some Ch38 G3's and noted the new PSU, but wasn't aware that the Ch69 variant had the old supplies.

 

With reference to the feedback thing, it's hardly ideal is it. I just don't like the sound of this, locking onto the closest one lark. I'm not sure. I haven't used it so I'm not prepared to comment as it would be unfair, but the idea concerns me. In THEORY it would never cause a problem, but RF isn't quite as straightforward as people would like to think.

 

Rob

[cedd]

Thanks

I've also just noticed that my newer trantec receiver looks to have a switch mode psu as the wallwart.

I think I'll have a word with the Trantec boys at Plasa Focus in a couple of weeks time. I guess as they seem to use smpsu's in their racked and ready sets, they won't see it as an issue.

I've nothing against linear psu's, but I'm going to need a reasonably well matched pair to do the diode trick, and I've not got 2 identical 12v psu's on the shelf, so I need to buy a new pair. Clearly with an investment like a mic rack, I need them to be reliable (hence the diodes). I'm pretty open as to which way I go with them.

 

Depending on a meeting with HR at work tomorrow, I'll either be in a position to buy another few RX's, or I'll be very grumpy...... We'll see!

 

On the subject of the Line 6 kit, like others I quite fancy having one or 2 in stock to try out. I've got a couple of shows coming up where it'd be nice to have a second pack and mic on the lead character. For this I need a few more channels to hand, and it'd be a good chance to A/B them. It'll only get used in an emergency, and I'd record both mics for a couple of nights to listen back to.

In reality it probably won't happen till I have a pair of ch38 racks done and working, by which time all sorts may have happened in terms of products on the market. Will see what happens!

[paulears]

Tried them out yesterday with big system and must say, the initial impression was pretty good. You can make the take off if you push it, and although feedback starts very quickly, it seems controllable - but the acoustic warning is not the same - there is a slight different 'tone' when you are approaching feedback, but it's very different from analogue. In my venue we always have problems when artistes leave the stage and walk into the audience, the side steps meet the auditorium floor right next to the main loudspeakers which make life very different - with the mic at performance level, I could walkd down and into the audience without all hell breaking out. Range is not a problem at all, with three mics on stage, a fourth 40m from the stage, at the sound desk had full RF level on the meters - which is pretty impressive - this is using one pair of aerials and the loop through connection of four receivers in the rack sitting on the amps.

 

Encouraging so far.

[HolyPhish]

This might be a silly question:

 

What happens to the signal when someone turns a microwave on in the nearby vicinity?

 

I know that they have an effect on 'wifi' and I was just wondering if they ruin this system too....

[boswell]

What did you think of the audio quality? I found it to be very clean & clear, no discernible background noise, (using £5 CPC headset mics).

[paulears]

I didn't find the audio quality any different to a real mic on a cable. No background noise I could detect, and although it was odd not having to set a gain on the mic, it did what they claimed - acted like a real wired mic. I tried yelling and holding the mic away and talking quietly - looking at the gain setting on the desk it seems very close to where a wired mic would sit. There are two wifi systems in the building, both were on, and didn't annoy me - I wasn't silly enough to ask the reverse question. There is a microwave in the crew room directly under the rack location - so tomorrow, I'll fire it up and see what happens.

[boswell]

There is a microwave in the crew room directly under the rack location - so tomorrow, I'll fire it up and see what happens.

Any excuse for a hot pastie :D

[paulears]

You don't know our crew room - few people would consider eating anything cooked in it! You know the nice stainless steel sinks and stuff commercial kitchens have? Well forget those and imagine a 40 year old sink with the enamel worn off so the actual colour is black and a horrible yellow - and a microwave where the cavity has rusted so badly the paint has fallen off. Lovely! We also have personalised mugs, as in not washed up since the last time you used them. Boiling water kills the germs by all accounts. The one and only towel is green and black in places where somebody wiped down a gearbox last year, and it is still there, festering away. Milk comes in two varieties, with and without limps. Coffee has some tea in it, and sugar - the tea bags gave coffee stains and the sugar has odd brown bits that are probably coffee, hopefully.