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Michael McQueen

Nomad RF block 21 and 24

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so I was requested by Rado to do a test of frequency scans on block 21 with my Nomad on and off, I did the same with block 24.

Bloc 24 with Nomad powered off

nomad-blk24-off.jpg

Block 24 with Nomad powered up

nomad-blk24-on.jpg

Block 21 with Nomad powered off

nomad-blk21-off.jpg

Block 21 with Nomad powered on

nomad-blk21-on.jpg

nothing special done with this test. bag was sitting on my kitchen counter, Nomad switch off, turned on BDS and powered up receivers and did a scan. Then turned on Nomad and re-scanned. Looks to be some RF in block 21 after the power up. Not sure if Glenn has anything scientific for this. My SRa's are fairly close to the unit as you can tell from the photos and i could move them away by a good inch or so. But honestly, I haven't had any dropouts from general usage, even while being in NYC last week, which was quite the ugly scan.

nyc-blk21.jpg

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Thanks for doing this test.

As we can all see, real world testing can be invaluable.

Does anyone have a Nomad and 411's to see if they are more immune to whatever the Nomad is putting out?

Could the scans be seeing something else NOT coming from Nomad?

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It would also be interesting to see similar scans with UCR411's. I stopped using my SRa in the bag and swapped it out with 411's because the SRa was affected more than the 411's by RF spray...

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Whoa, nothing else on in the bag? Are the SRas and the Nomad being powered by the same battery feed? Any RF filters in that feed? If so, what happens when you power the SRas on a separate battery or power supply, in that same position? I see that the RX is positioned over the Nomad's meter--does the spray change if the RX is positioned over the other end (left) of the recorder? The Zaxnet aspect of your Nomad wasn't fired up, was it?

thanks for the tests dude!

phil p

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Yes, thanks Jack!

I have a feeling there would be a vast improvement on the amount of RF spray across the SRa if it were moved to the outer pockets on a Petrol bag.

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I'll redo some more testing in the coming days. Didn't have much time to mess with it today.

Rescan with:

Sra's own power

Own power moved more way from bag(how far to get clean scan)

Bag power but out of bag and how far to get clean scan

And I'd be interested in what zax rx's are getting too.

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Alright. I'm just gonna ask because I don't understand.

Why would a recorder affect RF? What is in it that causes this issue?

Just about every peice of electronics can potential cause RFI. It's just when electricity is passing through any medium it creates a electromagnetic field. Even though it is relatively very weak in high end recorders, the use of highly sensitive receivers used right next to any source of RFI will probably show it.

When you hear about recorders with internal HDD's having relatively more RFI than solid state recorders it is likely because the electric motor that spins the platter in the HDD is actually using a magnetic field to make the platter spin, thus emitting more RF than a recorder that didn't have to spin up a little electric motor.

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All digital mixers and recorders use internal RF frequency signals to move data within the unit. It is the RF energy created by these signals that causes interference when the RF energy is allowed to radiate either from the case itself or from cables pluged into the case.

Zaxcoms Nomad case design and its connections to external cables are all designed with RF supression in mind. And we have no complaints of any excessive RF radiation to date.

The best thing that anyone can do is to seperate any digital product from receiver antennas by as great a distance as possible. Even 6 inches can be a big help over nothing.

The Zaxnet 2.4 GHz signal has a high pass filter so interference to UHF radios is very unlikely.

Glenn

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All digital mixers and recorders use internal RF frequency signals to move data within the unit. It is the RF energy created by these signals that causes interference when the RF energy is allowed to radiate either from the case itself or from cables pluged into the case.

Zaxcoms Nomad case design and its connections to external cables are all designed with RF supression in mind. And we have no complaints of any excessive RF radiation to date.

The best thing that anyone can do is to seperate any digital product from receiver antennas by as great a distance as possible. Even 6 inches can be a big help over nothing.

The Zaxnet 2.4 GHz signal has a high pass filter so interference to UHF radios is very unlikely.

Glenn

Glenn,

I sent you a PM on this forum and the Zaxcom forum. Please read and then call me on my cell: 651-470-1637

I saw very little rf spray into my Lectro 211's by the way. There was some but nothing that was a problem.

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Just about every peice of electronics can potential cause RFI. It's just when electricity is passing through any medium it creates a electromagnetic field. Even though it is relatively very weak in high end recorders, the use of highly sensitive receivers used right next to any source of RFI will probably show it.

When you hear about recorders with internal HDD's having relatively more RFI than solid state recorders it is likely because the electric motor that spins the platter in the HDD is actually using a magnetic field to make the platter spin, thus emitting more RF than a recorder that didn't have to spin up a little electric motor.

Thank you. It all makes sense to me now.

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Can you tell us about how you are powering your RX and Nomad? Do they share a feed/battery? Did how you routed the DC ables make a diff?

phil p

411's and Nomad are both being powered from a communal NP1. No special filtration.

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Looks very similar to my 552 and 21 Block SRas.

I dont mind leaving my Sras out of the bag but an antenna distro should be a better solution.

When the PSC RF multi SMa is released.

411's block 25 and 26 with Nomad off and on:

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