LarryF Posted May 17, 2011 Report Share Posted May 17, 2011 We have tested the D4T transmitter and the Quadra transmitter next to our receivers and found no detectable bleed. A little more subtle point is we also found there was no induced RF noise in un-bypassed lavalieres or unfiltered audio inputs. The occupied bandwidth is so wide (5 MHz) that there is very little energy at the audio frequencies. On top of that, the modulation method has a relatively low AM component. Best, Larry F Lectro Snip This is why the Lectro D4 was appealing, no pickup of RF bleed at all in my receivers even with the Tx right next to My RX's. Snip Quote Link to comment Share on other sites More sharing options...
PTA Posted May 17, 2011 Report Share Posted May 17, 2011 I can post a pic if you would like to see what it looks like. That would be great. We have tested the D4T transmitter and the Quadra transmitter next to our receivers and found no detectable bleed. A little more subtle point is we also found there was no induced RF noise in un-bypassed lavalieres or unfiltered audio inputs. The occupied bandwidth is so wide (5 MHz) that there is very little energy at the audio frequencies. On top of that, the modulation method has a relatively low AM component. Best, Larry F Lectro Larry, I really do like that aspect of the D4. The downside that I noticed is that the Tx takes quite a bit of power and drains my NP about 2 times as much so instead of 10 hrs on my setup, I'm getting 5. Is there any chance the D4 will ever have less power consumption? Quote Link to comment Share on other sites More sharing options...
TimPitot Posted May 17, 2011 Report Share Posted May 17, 2011 Here are some scans I did, both with my Zaxcom turned on and turned off, they were both done with the filter antenna mounted on my back. The receivers are not usually on top of one another, I put them there for the pic, I get very similar scans regardless of where in the bag they sit. Wierdly, the top SRa gets a lot more RFI despite them both being about 8 months old. Any thoughts? Larry? Zax powered off [img alt=photo width=640 height=426] Zaxcom powered on [img alt=photo width=640 height=426] They both give similarly crap range, despite the extra RFI displaying on the top RX. Quote Link to comment Share on other sites More sharing options...
TimPitot Posted May 17, 2011 Report Share Posted May 17, 2011 I also tried moving the whole TRX900 away from the bag (usially it sits outside in one of those Petrol pouches) - no difference. Quote Link to comment Share on other sites More sharing options...
Rob Beal Posted May 17, 2011 Report Share Posted May 17, 2011 Since I am getting RF spray from my ZFR100, which has no transmitter, it is likely that some of the RF spray from the TRX900 is coming from the recorder mechanism (or timecode generator) and therefore wouldn't be eliminated by the filtered antenna. Getting the zaxcom unit physically away from the bag should eliminate the issue though... strange that that isn't the case in Tim's setup. Quote Link to comment Share on other sites More sharing options...
jason porter Posted May 17, 2011 Report Share Posted May 17, 2011 Here you go- That would be great. Quote Link to comment Share on other sites More sharing options...
jason porter Posted May 17, 2011 Report Share Posted May 17, 2011 and the range is good when the Zaxcom hop is off? When I perform a Scan, I get similar results, the Rx nearer the Zaxcom Tx has a solid line across the bottom of the RF meter. If I just look at the RF meter when not in Scan Mode it is usually just a little blip that comes in and out. Here are some scans I did, both with my Zaxcom turned on and turned off, they were both done with the filter antenna mounted on my back. The receivers are not usually on top of one another, I put them there for the pic, I get very similar scans regardless of where in the bag they sit. They both give similarly crap range, despite the extra RFI displaying on the top RX. Quote Link to comment Share on other sites More sharing options...
LarryF Posted May 17, 2011 Report Share Posted May 17, 2011 We have discussed a redesign down the road. The current packaging is not ideal. Best, Larry F Lectro Snip The downside that I noticed is that the Tx takes quite a bit of power and drains my NP about 2 times as much so instead of 10 hrs on my setup, I'm getting 5. Is there any chance the D4 will ever have less power consumption? Quote Link to comment Share on other sites More sharing options...
LarryF Posted May 17, 2011 Report Share Posted May 17, 2011 Hi Tim, I'm not sure why you are getting different display levels on the two receivers. As far as the reduction in range, try this: start separating items from your bag and testing range differences. First, I'd try just the SRa's by themselves with only the battery power. Then start moving items near the SR's =>ONE<= at a time and see what happens to the range. You can look at the display, but usually by the time you see anything on the display, your range has dropped by a factor of 3. It is possible that RF is coming off the cases or cables of various items and not necessarily from the filtered antenna. Best Regards, Larry Fisher Lectrosonics Quote Link to comment Share on other sites More sharing options...
PTA Posted May 17, 2011 Report Share Posted May 17, 2011 We have discussed a redesign down the road. The current packaging is not ideal. Best, Larry F Lectro Any idea how far down the road? Quote Link to comment Share on other sites More sharing options...
LarryF Posted May 17, 2011 Report Share Posted May 17, 2011 Next NAB. L Any idea how far down the road? Quote Link to comment Share on other sites More sharing options...
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