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Anyone find RF Hash/interference with SD 633?


Freeheel
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Not wishing to Hi-jack this thread but has anyone with a 633 used any other make of card apart from Delkin CF or SD card? Sound Devices recommended Sandisk for the 7 series and I followed their advice and have not have any issues whatsoever with this make and consequently have a lot of 2, 4 and 8Gb ones in stock. The Delkin cards they are now recommending  for the 633 are always the larger capacity ones and they don't mention anything less than 16Gb which tend to be expensive, when practicality tells me to use a 4 or 8Gb ones when recording 2 or 3 tracks.

Malcolm Davies. A.m.p.s.

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I've been following the 633 threads but haven't come across any comments about whether it throws any radio interference into your wirelesses.  I would think not, since it doesn't have a hard drive, but I though I'd ask... 

 

Any Comments?

 

Cheers,

Brent Calkin

 

Not to say the recorder does spray RFI but having a hard drive or no, does not singularly determine this outcome. Ie there are a few hard drive less recorders out there that do spray some RFI. I imagine it will be a while (2 to 3 months) before the 633 gets used in anger with a range of wireless mics and frequencies that represent what folks like use around the world. For the same reasons if there were issues with lectro or zaxcom wireless on US freqs we would hear about very quickly. The findings from use with Wisycom and other euro brands will be along later.

 

Dan. 

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My tascam dr-100 had a pretty mean spike at 559.5.

Mi initial testing with the 633 is that it's pretty well controlled though I'm seeing a tiny bit of very low level gunk in my block 20, 401 compared to free air or being next to my 442. Block 26 is unchanged for me.

Nothing that I can't work around and it's so low it's hardly worth mentioning. One dot on the scan, if that.

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Not wishing to Hi-jack this thread but has anyone with a 633 used any other make of card apart from Delkin CF or SD card? Sound Devices recommended Sandisk for the 7 series and I followed their advice and have not have any issues whatsoever with this make and consequently have a lot of 2, 4 and 8Gb ones in stock. The Delkin cards they are now recommending  for the 633 are always the larger capacity ones and they don't mention anything less than 16Gb which tend to be expensive, when practicality tells me to use a 4 or 8Gb ones when recording 2 or 3 tracks.

Malcolm Davies. A.m.p.s.

At approx. $40 for a 16 gig card it seems hardly worth the risk of using an unapproved card.  Even at any price it's not worth it.  

 

 

Andy

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I was present at the official unveiling at LSC in Los Angels, and recall hearing that there was no RF spray, which they made a point of telling us. I also believe they mentioned something about being sure to make sure there was none, so there you go. Also, I want a 633, now accepting hand outs!

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I was present at the official unveiling at LSC in Los Angels, and recall hearing that there was no RF spray, which they made a point of telling us. I also believe they mentioned something about being sure to make sure there was none, so there you go. Also, I want a 633, now accepting hand outs!

It's almost like they've made this sort of machine before. They've become very good at it by this point.

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I was present at the official unveiling at LSC in Los Angels, and recall hearing that there was no RF spray, which they made a point of telling us. I also believe they mentioned something about being sure to make sure there was none, so there you go. Also, I want a 633, now accepting hand outs!

At the unveiling at Gotham, Pat McConnel explained that the 633's casing was built to shield 100% of RF spray, and that it had been thoroughly tested.

To the OP, I'm positive that you will not experience any RF spray on your 633 if you decide to go ahead and buy it.

Good luck!

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  • 6 years later...

Reviving this thread.

 

On my cart I have 2 ALP 620 shark fins 10 feet in the air feeding a Venue2 with VRT2's, using a combo of SMQV's and wideband transmitters. I operate in A band and block 21. I work in NY and I haven't had too many unusual RF problems over the past few years. Now that I'm back to work, I'm noticing a lot of RF problems that just shouldn't be there. Signal that falls below full (down to 60% at times) when I have line of sight to the transmitters and some fuzz/snow/pops and it's been more than a little frustrating. My utility and I are constantly troubleshooting and trying to follow best practices.

 

It occurred to me yesterday that maybe I'm getting RF spray from my 664 and 744 which sit directly above the Venue2. Is this a possibility or do the shark fins being up high circumvent that?

 

And does anyone have access to any charts/specs on the SD rf spray? They've taken down their page on the 744 spray, I'm guessing years ago. Why would they do that?: https://www.sounddevices.com/notes/recorders/7-series-rf/

 

Thanks,

Ben

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1 hour ago, BAB414 said:

Signal that falls below full (down to 60% at times) when I have line of sight to the transmitters and some fuzz/snow/pops and it's been more than a little frustrating. My utility and I are constantly troubleshooting and trying to follow best practices.

The only time I've had trouble in the A1 band (anything outside of A1 these days in LA is pretty useless ever since the recent repack), it has usually been because of a walkie transmitting near while I'm in the 4xxmhz frequencies.  Speaking of repack, I think everything technically finished in July this year while we were all quarantining so maybe things that used to be clear aren't anymore for you?  Also, looks like you have a lot of Public Safety channels in the A1 range.  You're not transmitting in that range are you?

Screen Shot 2020-10-30 at 9.23.43 AM.png

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2 hours ago, BAB414 said:

Reviving this thread.

 

On my cart I have 2 ALP 620 shark fins 10 feet in the air feeding a Venue2 with VRT2's, using a combo of SMQV's and wideband transmitters. I operate in A band and block 21. I work in NY and I haven't had too many unusual RF problems over the past few years. Now that I'm back to work, I'm noticing a lot of RF problems that just shouldn't be there. Signal that falls below full (down to 60% at times) when I have line of sight to the transmitters and some fuzz/snow/pops and it's been more than a little frustrating. My utility and I are constantly troubleshooting and trying to follow best practices.

 

It occurred to me yesterday that maybe I'm getting RF spray from my 664 and 744 which sit directly above the Venue2. Is this a possibility or do the shark fins being up high circumvent that?

 

And does anyone have access to any charts/specs on the SD rf spray? They've taken down their page on the 744 spray, I'm guessing years ago. Why would they do that?: https://www.sounddevices.com/notes/recorders/7-series-rf/

 

Thanks,

Ben

Hi Ben,

With the good separation you have, I don't think the SD products are the problem. Those problems were common with bag setups where the SD was close to the receivers.

 

If you haven't already, do an RF scan with the Venue to make sure you have a clean RF spot for your selected frequencies.

 

Also try one transmitter on at a time just in case multiple transmitter are causing intermod. The proper selection of transmitter frquencies will dodge this problem

 

If the signal falls to 60% and it is interference, it must be very strong with the interference overloading the RF inputs, which is hard to do. You need to do some methodical, logical trouble shooting. Start by turning off those things that might be causing interference such as the SD's. Keep turning things off until the problem goes away. If it doesn't, move 100's of feet away from any video transmitters, walkies, controllers or any other thing using RF on set. You can also simulate this by setting up your sound rig at home and see if the problem exists. That will tell you if it is location specific. This may be the most important thing to try.

 

Check out your antenna system by getting rid of it temporarily. Put simple whip antennas on your Venue with the Venue out in the open and see if it now works properly. If it does, your problem may be as simple as bad cables. 

 

Basically, all the trouble shooting here is eliminate and simplify. If this doesn't resolve anything then it may be time to substitute a different receiver to see if the problem is in the Venue.

Best Regards,

Larry Fisher 

 

 

 

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2 hours ago, BAB414 said:

Reviving this thread.

 

On my cart I have 2 ALP 620 shark fins 10 feet in the air feeding a Venue2 with VRT2's, using a combo of SMQV's and wideband transmitters. I operate in A band and block 21. I work in NY and I haven't had too many unusual RF problems over the past few years. Now that I'm back to work, I'm noticing a lot of RF problems that just shouldn't be there. Signal that falls below full (down to 60% at times) when I have line of sight to the transmitters and some fuzz/snow/pops and it's been more than a little frustrating. My utility and I are constantly troubleshooting and trying to follow best practices.

 

It occurred to me yesterday that maybe I'm getting RF spray from my 664 and 744 which sit directly above the Venue2. Is this a possibility or do the shark fins being up high circumvent that?

 

And does anyone have access to any charts/specs on the SD rf spray? They've taken down their page on the 744 spray, I'm guessing years ago. Why would they do that?: https://www.sounddevices.com/notes/recorders/7-series-rf/

 

Thanks,

Ben

The 744 is a sprayer for sure: I ended up putting some of that RF filter cloth between the 744 and my RX in the pouch of a PortaBrace bag.  That and the slight increase in distance caused by all the layers of the bag+pouch fabric made it workable, but there is still some spray noticeable when the 744 is powered up.   I have not noticed spray in my 6xx machines, and they live in similar proximity to the RX in their bags.

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In addition to Larry's recommendations, I will suggest looking at some band filtering and possibly attenuation. The ALP690 antenna offers both. With your ALP620s and short cables, you are likely pulling in more RF than you really need, which raises the noise floor and can increase intermods in the receiver. By putting a bandpass filter at "6" on the antennas (470-608) and then bringing down the gain by say 3dB (set the gain to -3), you will see your noise floor go down and also you'll reduce the possibility of strong out-of-band signals desensitizing your receivers. 

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Fun to see this thread again 7 years later!   I will confirm Philip's confirmation on the 744 being quite a nasty sprayer of RF when in a bag, and it was a big part of my push to quickly get a 633 seven years ago once I determined it didn't have the same problem.  As Larry stated, the separation you have with your antennas should make the spray of the 744 pretty negligible.  It generally only took a few inches of spacing to knock down the spurious spray enough to stop worrying about it.  Hard to do in a bag, but not an issue  with a 10 ft antenna. 

 

Cheers,

Brent Calkin

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