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[Jordan Wolf]

Hi All,

I was wondering if there was a similar unit for VHF?

I saw that Shure makes the UA860V, but it’s a bit different and more unsightly than RFVenue’s offering.

I have a friend doing interview-style video broadcasts, and the LED panel lights are apparently spewing RF hash. I recommended blackwrap on the backside of the panels and placing the panel in the null of the LPDA, but thought there might be other options.

[Keith Broughton]

You could try placing 1/2 wave antennas behind the drape, close to the transmitters and that would get away from the rear of the lights and give some distance from the RF noise source.
Looking at the setup in the pics, it seems like a lot more antenna than the job requires.

[Jordan Wolf]

You could try placing 1/2 wave antennas behind the drape, close to the transmitters and that would get away from the rear of the lights and give some distance from the RF noise source.
Looking at the setup in the pics...1

Yeah, that was another suggestion.

...t seems like a lot more antenna than the job requires.

I agree. Not my event, so I’m not sure what they had access to.

[Ike Zimbel]

Yeah, that was another suggestion.
I agree. Not my event, so I’m not sure what they had access to.

+1 And...make sure that they have the gain switch on the antennas set to the lowest position (I believe it's -6dB). If the switch is, say, in the +12 position, they're going to have lots of issues.

[Jordan Wolf]

...[a]nd...make sure that they have the gain switch on the antennas set to the lowest position...

That’s one thing he did have in-place already. I think repositioning the LPDAs so the LED panels were in the null helped enough.

Aside from shielding via blackwrap, etc., to reduce the RF spew, do you think some 3dB or 6dB pads would have helped lower the overall noise floor so that the received RF would have a higher overall S/N ratio?

[Jerome Malsack]

Band width RF filters RFVenue and others sell but Cost is as high as the antenna. 

Yes placing the antenna behind the curtain works but the wall behind the added metal from the pipe and drape would need some additional space. 
1/4 wave rule for vhf is about 2 feet from wall and pipe and drape metal.  That would put the pipe and drape about 5 feet into the room from the wall to prevent problems.

[Dave Garoutte]

How about from the ceiling above sight lines?

[Ike Zimbel]

That’s one thing he did have in-place already. I think repositioning the LPDAs so the LED panels were in the null helped enough.

Aside from shielding via blackwrap, etc., to reduce the RF spew, do you think some 3dB or 6dB pads would have helped lower the overall noise floor so that the received RF would have a higher overall S/N ratio?

Yes. With RF signal levels all you need is enough. IOW, if you use, say, 3dB pads, and the RX still shows full bars on the LED display when the Tx is on, you have just lowered your noise floor by 3dB with no cost to your signal.
From your picture, it looks like the distances involved are quite small, so I suspect you would have quite a lot of RF headroom to work with.

[Matthew Knischewsky]

Hi All,

I was wondering if there was a similar unit for VHF?

I saw that Shure makes the UA860V, but it’s a bit different and more unsightly than RFVenue’s offering.

I have a friend doing interview-style video broadcasts, and the LED panel lights are apparently spewing RF hash. I recommended blackwrap on the backside of the panels and placing the panel in the null of the LPDA, but thought there might be other options.

I know this is the RF forum but the photo would seem to indicate it's a sit-down interview, no audience. Has you friend considered using wired mics?

[Jordan Wolf]

...Has you friend considered using wired mics?

Knowing the production company, I’m almost certain it would have been discussed beforehand and the client demanded a wireless “solution”. They’re always “right”, right?

I hardwire whenever I can, at the very least for a backup to the backup’s backup, lol.

I’ve never been one to recommend a less-than-ideal solution to achieve a desired look/perception, but that’s not always my decision. Form over function is not my motto.

[Jason Glass]

Hi All,

I was wondering if there was a similar unit for VHF?

I saw that Shure makes the UA860V, but it’s a bit different and more unsightly than RFVenue’s offering.

I have a friend doing interview-style video broadcasts, and the LED panel lights are apparently spewing RF hash. I recommended blackwrap on the backside of the panels and placing the panel in the null of the LPDA, but thought there might be other options.

You can place those LPDA's flat on the floor (as long as it's not made of conductive metal), located within a few feet of the TX and pointing toward the talent.  The closer the better, such as directly beneath them on the set.  They even work well under carpet or beneath wooden set risers.

This achieves minimum distance to the desired source of signal and maximum distance to the source of noise, which allows the inverse square law of free space loss to work in your favor to improve CNR.

This is exactly the same application and philosophy of the RF Spotlight that is designed as a low-gain antenna, but substituting a high-gain antenna in a way that makes it perform as a low-gain device.

Violation of near-field obstruction best practices and its associated antenna detuning in this case is desirable to reduce the overall gain of the system as appropriate for such a close range of operation.  VHF has very low loss in dB per foot through properly spec'd coax, so its length in that small room will likely be negligible.  You may even wish to insert more attenuation as Ike suggested.

If this configuration doesn't work perfectly in the scenario that you've described, there may be other problems happening in addition to noisy lighting fixtures and a deeper dive into your components and procedures is necessary.

[Scott Helmke]

I've been known to tape a standard half-wave (what comes with every Shure receiver except for the very cheapest) to something right in the middle of the action. Maybe taped to the back of a chair leg?

[Matthew Knischewsky]

Knowing the production company, I’m almost certain it would have been discussed beforehand and the client demanded a wireless “solution”. They’re always “right”, right?

I hardwire whenever I can, at the very least for a backup to the backup’s backup, lol.

I’ve never been one to recommend a less-than-ideal solution to achieve a desired look/perception, but that’s not always my decision. Form over function is not my motto.

I had to make the suggestion! It would seem that some people forget that the simple solutions should be the most obvious. In my current role that happens all the time...

[Jordan Wolf]

I've been known to tape a standard half-wave (what comes with every Shure receiver except for the very cheapest) to something right in the middle of the action. Maybe taped to the back of a chair leg?

Hmm...that’s a good thought. Maybe I’ll give that a try myself sometime!

[Jordan Wolf]

I had to make the suggestion! It would seem that some people forget that the simple solutions should be the most obvious. In my current role that happens all the time...

Simple is better, in my experience, as well - less to go wrong, less to troubleshoot, etc.

[Jordan Wolf]

You can place those LPDA's flat on the floor (as long as it's not made of conductive metal), located within a few feet of the TX and pointing toward the talent.  The closer the better, such as directly beneath them on the set.  They even work well under carpet or beneath wooden set risers.

This achieves minimum distance to the desired source of signal and maximum distance to the source of noise, which allows the inverse square law of free space loss to work in your favor to improve CNR.

This is exactly the same application and philosophy of the RF Spotlight that is designed as a low-gain antenna, but substituting a high-gain antenna in a way that makes it perform as a low-gain device.

Violation of near-field obstruction best practices and its associated antenna detuning in this case is desirable to reduce the overall gain of the system as appropriate for such a close range of operation.  VHF has very low loss in dB per foot through properly spec'd coax, so its length in that small room will likely be negligible.  You may even wish to insert more attenuation as Ike suggested.

If this configuration doesn't work perfectly in the scenario that you've described, there may be other problems happening in addition to noisy lighting fixtures and a deeper dive into your components and procedures is necessary.

Very interesting!

[ProSoundWeb Community]