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John Updike

Receiver advice

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Hi, first post and happy to be here.

 

I need some advice. 

 

I've got a live event coming up which needs recording. It's hosted in a relatively small/ medium sized room with around 60 guests and 3 speakers with a Q&A. I planned to work in the bag with 3 wisycom kits and two hand held mics which are sennheiser G3 body pack type TX And RX 

 

I've used the same rig before a few times. The wisycom in channel 38 have always been rock solid where as the G3 kit has been a bit crap really. Firstly scanning for a  free frequency, one of the the G3 receivers actually recommends that I use the same frequency the other G3 RX is on! 

 

I don't trust them, it's a live show so I can't really have them fail on me which they seem to be doing from the occasional bursts of static to pops and drop outs depending on which angle the rx is at. 

 

I know the diversity and range is not great on these body packs but what makes the wisycom so stable over them?

 

I'm looking to sell the G3 RXs and perhaps keep the hand held tx mics. After buying my 633 mixer, 4 channels of wisycom and lav mics it's left me a bit poor and although I'd like to buy a venue rack or wisycom stereo rack I just can't afford it at the moment. This is where I need some advice.

 

Given I've got the hand held mics would two G3 500 racks be considered an upgrade in terms of stability and intermod resistance etc over the body worn G3 rx units?... the diversity system I've been told is better at work on the racks with the standard antennas. 

 

Buying the 500 units would in turn allow me to also eventually get some passive paddles and have my antennas off the ground for better line of sight too, would this also help fend off rougue issues from laptops and mobile phones in the room messing the receivers? 

My room range runs are not so long that I would need active antennas but I like the idea of Betso panels with their plus and minus amping, I presume a good fit for both long and shorter range. Is this making sense or am I throwing money away on a non suitable upgrade and I should just save up for a venue rack or similar which has better diversity and filtering etc. 

 

Any help would be appreciated 

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10 hours ago, John Updike said:

Firstly scanning for a  free frequency, one of the the G3 receivers actually recommends that I use the same frequency the other G3 RX is on! 

If only the Rx 1 was on (without matching Tx)  actually that is a sign that the scan was accurate, Rx1 + Rx2 show the same results in the same environment. G3 Rx are only receivers, they do not communicate with other Rx.  If you want to set it up properly, you make a scan with Rx1, switch on the respective Tx1 and then scan again for a clear Frequency with Rx 2. Now Rx 2 should NOT suggest the frequency Tx1 is already transmitting...

I use the G3 for IEM only, but they have impressed me during the years with their ruggedness and also signal stability. Zaxcoms, Lectros, Wisys...  can play their strenghts when it comes to congested RF, addidtional range, minimal Tx size  and extreme dynamics.

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I think that you could get away with a G3 100 series rack and get a similar performance as far as RF goes compared with the 500 series rack. I do think you'd get better performance with the Rack series just because you can put up better antennas,  it I don't know how much better. I e never compared side to side with sennheiser bag vs rack. Obviously the best route would be to go Lectrosonics or wisycom but only you can make that decision. 

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On 11/25/2017 at 11:40 AM, axel said:

If only the Rx 1 was on (without matching Tx)  actually that is a sign that the scan was accurate, Rx1 + Rx2 show the same results in the same environment. G3 Rx are only receivers, they do not communicate with other Rx.  If you want to set it up properly, you make a scan with Rx1, switch on the respective Tx1 and then scan again for a clear Frequency with Rx 2. Now Rx 2 should NOT suggest the frequency Tx1 is already transmitting.

 

Sadly this is the case, and not for the first time has this happened. 

Thanks for all the help. 

 

Has any one used the EM 2050 Sennheiser stereo rack? Would you know if my G3 hand held mics are compatible? I really like the idea of the built in active splitter to be used in the future when I can get a better budget and buy active antennas. Another question please, passive antenna paddles, How do they improve RF signal pick up? I understand antenna seperation is beneficial but is it also the area size of the paddle that is also beneficial? As by principal there is obviously no amplification being Passive 

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2 hours ago, John Updike said:

 

Sadly this is the case, and not for the first time has this happened. 

Thanks for all the help. 

 

Has any one used the EM 2050 Sennheiser stereo rack? Would you know if my G3 hand held mics are compatible? I really like the idea of the built in active splitter to be used in the future when I can get a better budget and buy active antennas. Another question please, passive antenna paddles, How do they improve RF signal pick up? I understand antenna seperation is beneficial but is it also the area size of the paddle that is also beneficial? As by principal there is obviously no amplification being Passive 

'paddles' are direction. signal amplification is used to compensate for splitting the signal (across RX) and/or long coax runs. 

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9 hours ago, John Updike said:

 

Sadly this is the case, and not for the first time has this happened. 

Thanks for all the help. 

 

Has any one used the EM 2050 Sennheiser stereo rack? Would you know if my G3 hand held mics are compatible? I really like the idea of the built in active splitter to be used in the future when I can get a better budget and buy active antennas. Another question please, passive antenna paddles, How do they improve RF signal pick up? I understand antenna seperation is beneficial but is it also the area size of the paddle that is also beneficial? As by principal there is obviously no amplification being Passive 

I believe they are compatible because you can use the sk2000 transmitters with the 300 series IEM. 

 

They are are both Omni and directional antennas. Just depends on which one you get. The sna600 from lectrosonics is not directional but does improve reception. There are a lot of directional antennas to choose from.  Maybe Larry can pitch in on the physics and electronics of exactly how and why external antennas are better than whips. 

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7 hours ago, ryanpeds said:

Maybe Larry can pitch in on the physics and electronics of exactly how and why external antennas are better than whips. 

 

I think I've got the jist of the matter. But if he's around that would be beneficial. 

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9 hours ago, ryanpeds said:

I believe they are compatible because you can use the sk2000 transmitters with the 300 series IEM. 

 

They are are both Omni and directional antennas. Just depends on which one you get. The sna600 from lectrosonics is not directional but does improve reception. There are a lot of directional antennas to choose from.  Maybe Larry can pitch in on the physics and electronics of exactly how and why external antennas are better than whips. 

 

External antennas can be mounted higher and with more separation than whips on a receiver. Typically the receiver is position constrained on a cart, rack or camera. On top of that, the separation of the antennas for diversity on the receiver is less than optimal because everyone wants smaller receivers. Those two factors are pretty obvious. Less obvious is that the ground plane for a whip should be theoretically  infinite in size (ignoring the smaller, tuned ground plane case). A receiver case is fat and has good area but is still not an ideal ground plane. This why Lectro receiver whips are cut to a different length than for the 1/4 wavelength rule. To make up for ground plane mis-tuning. 

 

Common external antennas such as the SNA-600 dipole or ALP-500 log periodics, do not need a ground plane since they are balanced antennas. Mounting a whip antenna high in the air would make a good antenna except you need a matching ground plane up there also; just mounting the whip on the end of a co-ax is not very good. External antennas also can be mounted away from other metallic reflecting or interfering objects. External antennas also can be mounted to be line of sight with fewer lumps of wet protoplasm between the transmitter and receiver antennas.

 

For the relative importance of all these factors, imagine mounting two ALP-500 log periodics on a UM 411 receiver on a camera. Not only would it look funny as Hell, but the antennas wouldn't work that well. They would be low to the ground, interact with each other due to small separation, not have sufficient diversity separation and sometimes be pointing in the wrong direction.

 

So in conclusion, there is nothing magically better about external antennas such as having a lot more gain. They only have a little more.Their biggest benefit is their (usually) much improved placement. 

Best,

Larry F

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I've been using a couple of G3s with the handheld sticks for the last 12 months and I have to say they've worked perfectly, right across Europe and beyond.  They're only plugged into an SQN so there's nothing really "digital" going on in the bag that could cause problems.  I've used them on recorded and live work and had no issues at all.

 

Are you using the correct cables, and are they tightened up fully on the receiver?  The Sennheiser cables form part of the antenna and you can have problems if you don't use the locking ring on the minijack fully.

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Thanks Larry. Not as much magic going on as I would have thought. As always your insight and knowledge are much appreciated. 

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7 hours ago, Lancashire soundie said:

Are you using the correct cables, and are they tightened up fully on the receiver?  The Sennheiser cables form part of the antenna and you can have problems if you don't use the locking ring on the minijack fully.

 

Thanks everyone. 

 

Lancashire I didn't know this! I'm using a mini jack to 3 pin mini XLR as the RX output due to it being connected to a line input on my 633

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On 27/11/2017 at 9:20 PM, John Updike said:

 

Thanks everyone. 

 

Lancashire I didn't know this! I'm using a mini jack to 3 pin mini XLR as the RX output due to it being connected to a line input on my 633

 

Ensure you're using the correct Sennheiser cable (they have a blue ring on the XLR).

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